DOKK Library

Specialized Emacs Features

Authors Free Software Foundation

License GFDL-1.3-or-later

Plaintext
Specialized Emacs Features
This manual describes specialized features of Emacs.
Copyright c 2004–2023 Free Software Foundation, Inc.
     Permission is granted to copy, distribute and/or modify this document under
     the terms of the GNU Free Documentation License, Version 1.3 or any later
     version published by the Free Software Foundation; with no Invariant Sections,
     with the Front-Cover Texts being “A GNU Manual,” and with the Back-Cover
     Texts as in (a) below. A copy of the license is included in the section entitled
     “GNU Free Documentation License”.
     (a) The FSF’s Back-Cover Text is: “You have the freedom to copy and modify
     this GNU manual.”
                                                                                                                                  i



Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Editing Pictures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
   Basic Editing in Picture Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
   Controlling Motion after Insert. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   Picture Mode Tabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
   Picture Mode Rectangle Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
   Auto Reverting Non-File Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
      Auto Reverting the Buffer Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
      Auto Reverting Dired buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Subdirectory Switches in Dired . . . . . . . . . . . . . . . . . . . . 7

More advanced features of the Calendar and Diary . . 8
   Customizing the Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
   Customizing the Holidays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
   Converting from the Mayan Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
   Date Display Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
   Time Display Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
   Customizing the Diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
   Diary Entries Using non-Gregorian Calendars . . . . . . . . . . . . . . . . . . . . . . . 13
   Diary Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
   Fancy Diary Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
   Sexp Entries and the Fancy Diary Display . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Merging Files with Emerge . . . . . . . . . . . . . . . . . . . . . . . 20
   Overview of Emerge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
   Submodes of Emerge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
   State of a Difference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
   Merge Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
   Exiting Emerge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
   Combining the Two Versions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
   Fine Points of Emerge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Advanced VC Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
   Miscellaneous Commands and Features of VC . . . . . . . . . . . . . . . . . . . . . . .                                 25
     Change Logs and VC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            25
     Deleting and Renaming Version-Controlled Files . . . . . . . . . . . . . . . . .                                      25
     Revision Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   26
     Inserting Version Control Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                       27
     Editing VC Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .               27
                                                                                                                                ii



      Preparing Patches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
    Customizing VC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
      General Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
      Options for RCS and SCCS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
      Options specific for CVS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Fortran Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
    Motion Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
    Fortran Indentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
       Fortran Indentation and Filling Commands . . . . . . . . . . . . . . . . . . . . . . 32
       Continuation Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
       Line Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
       Syntactic Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
       Variables for Fortran Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
    Fortran Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
    Auto Fill in Fortran Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
    Checking Columns in Fortran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
    Fortran Keyword Abbrevs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Emacs and MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
    Keyboard Usage on MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
    Mouse Usage on MS-DOS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
    Display on MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
    File Names on MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
    Printing and MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
    International Support on MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
    Subprocesses on MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Appendix A                        GNU Free Documentation License . . 45

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
                                                                                            1



Introduction
This manual contains detailed information about various features that are too specialized to
be included in the printed Emacs manual. It is intended to be readable by anyone having a
basic knowledge of Emacs. However, certain sections may be intended for a more specialized
audience, such as Elisp authors. This should be clearly pointed out at the beginning of these
sections.
   Certain packages (or collections of related features) have their own manuals, separate
from the main Emacs manual. This manual is intended as a complement, rather than an
alternative, to reading those additional manuals. In a nutshell, it is a collection of smaller
specialized features (or extra detail about standard features), too small or too obscure to
justify their own manual, or inclusion in the printed Emacs manual. The chapters in this
manual are, however, included (at the relevant places) in the main Emacs manual when it is
formatted as an Info document.
   Sections intended specifically for Elisp programmers can follow the style of the Elisp
manual. Other sections should follow the style of the Emacs manual.
                                                                                            2



Editing Pictures
To edit a picture made out of text characters (for example, a picture of the division of a
register into fields, as a comment in a program), use the command M-x picture-mode to
enter Picture mode.
    In Picture mode, editing is based on the quarter-plane model of text, according to which
the text characters lie studded on an area that stretches infinitely far to the right and
downward. The concept of the end of a line does not exist in this model; the most you can
say is where the last nonblank character on the line is found.
    Of course, Emacs really always considers text as a sequence of characters, and lines
really do have ends. But Picture mode replaces the most frequently-used commands with
variants that simulate the quarter-plane model of text. They do this by inserting spaces or
by converting tabs to spaces.
    Most of the basic editing commands of Emacs are redefined by Picture mode to do
essentially the same thing but in a quarter-plane way. In addition, Picture mode defines
various keys starting with the C-c prefix to run special picture editing commands.
    One of these keys, C-c C-c, is particularly important. Often a picture is part of a larger
file that is usually edited in some other major mode. Picture mode records the name of the
previous major mode so you can use the C-c C-c command (picture-mode-exit) later to
go back to that mode. C-c C-c also deletes spaces from the ends of lines, unless given a
numeric argument.
    The special commands of Picture mode all work in other modes (provided the picture
library is loaded), but are not bound to keys except in Picture mode. The descriptions below
talk of moving “one column” and so on, but all the picture mode commands handle numeric
arguments as their normal equivalents do.
    Turning on Picture mode runs the hook picture-mode-hook. Additional extensions to
Picture mode can be found in artist.el.

Basic Editing in Picture Mode
Most keys do the same thing in Picture mode that they usually do, but do it in a quarter-
plane style. For example, C-f is rebound to run picture-forward-column, a command
which moves point one column to the right, inserting a space if necessary so that the actual
end of the line makes no difference. C-b is rebound to run picture-backward-column,
which always moves point left one column, converting a tab to multiple spaces if necessary.
C-n and C-p are rebound to run picture-move-down and picture-move-up, which can
either insert spaces or convert tabs as necessary to make sure that point stays in exactly
the same column. C-e runs picture-end-of-line, which moves to after the last nonblank
character on the line. C-a runs picture-beginning-of-line. (The choice of screen model
does not affect beginnings of lines; the only extra thing this command does is update the
current picture column to 0.)
   Insertion of text is adapted to the quarter-plane screen model through the use of Overwrite
mode (see Section “Minor Modes” in the Emacs Manual.) Self-inserting characters replace
existing text, column by column, rather than pushing existing text to the right. RET runs
picture-newline, which just moves to the beginning of the following line so that new text
will replace that line.
Editing Pictures                                                                             3



    In Picture mode, the commands that normally delete or kill text, instead erase text
(replacing it with spaces). DEL (picture-backward-clear-column) replaces the preced-
ing character with a space rather than removing it; this moves point backwards. C-d
(picture-clear-column) replaces the next character or characters with spaces, but does
not move point. (If you want to clear characters to spaces and move forward over them, use
SPC.) C-k (picture-clear-line) really kills the contents of lines, but does not delete the
newlines from the buffer.
    To do actual insertion, you must use special commands. C-o (picture-open-line)
creates a blank line after the current line; it never splits a line. C-M-o (split-line) makes
sense in Picture mode, so it is not changed. C-j (picture-duplicate-line) inserts another
line with the same contents below the current line.
    To do actual deletion in Picture mode, use C-w, C-c C-d (which is defined as delete-char,
as C-d is in other modes), or one of the picture rectangle commands (see [Rectangles in
Picture], page 4).

Controlling Motion after Insert
Since self-inserting characters in Picture mode overwrite and move point, there is no essential
restriction on how point should be moved. Normally point moves right, but you can specify
any of the eight orthogonal or diagonal directions for motion after a self-inserting character.
This is useful for drawing lines in the buffer.
C-c <
C-c LEFT    Move left after insertion (picture-movement-left).
C-c >
C-c RIGHT Move right after insertion (picture-movement-right).
C-c ^
C-c UP      Move up after insertion (picture-movement-up).
C-c .
C-c DOWN    Move down after insertion (picture-movement-down).
C-c `
C-c Home    Move up and left (“northwest”) after insertion (picture-movement-nw).
C-c '
C-c PageUp
C-c prior Move up and right (“northeast”) after insertion (picture-movement-ne).
C-c /
C-c End     Move down and left (“southwest”) after insertion
            (picture-movement-sw).
C-c \
C-c PageDown
C-c next Move down and right (“southeast”) after insertion
          (picture-movement-se).
   Two motion commands move based on the current Picture insertion direction. The
command C-c C-f (picture-motion) moves in the same direction as motion after insertion
currently does, while C-c C-b (picture-motion-reverse) moves in the opposite direction.
Editing Pictures                                                                               4



Picture Mode Tabs
 Two kinds of tab-like action are provided in Picture mode. Use M-TAB (picture-tab-
 search) for context-based tabbing. With no argument, it moves to a point underneath
 the next “interesting” character that follows whitespace in the previous nonblank line.
“Next” here means “appearing at a horizontal position greater than the one point starts
 out at”. With prefix argument, as in C-u M-TAB, this command moves to the next such
 interesting character in the current line. M-TAB does not change the text; it only moves point.
“Interesting” characters are defined by the variable picture-tab-chars, which should define
 a set of characters. The syntax for this variable is like the syntax used inside of ‘[...]’ in a
 regular expression—but without the ‘[’ and the ‘]’. Its default value is "!-~".
   TAB itself runs picture-tab, which operates based on the current tab stop settings; it is
the Picture mode equivalent of tab-to-tab-stop. Normally it just moves point, but with a
numeric argument it clears the text that it moves over.
    The context-based and tab-stop-based forms of tabbing are brought together by the
command C-c TAB (picture-set-tab-stops). This command sets the tab stops to the
positions which M-TAB would consider significant in the current line. The use of this command,
together with TAB, can get the effect of context-based tabbing. But M-TAB is more convenient
in the cases where it is sufficient.
   It may be convenient to prevent use of actual tab characters in pictures. For example,
this prevents C-x TAB from messing up the picture. You can do this by setting the variable
indent-tabs-mode to nil.

Picture Mode Rectangle Commands
Picture mode defines commands for working on rectangular pieces of the text in ways that
fit with the quarter-plane model. The standard rectangle commands may also be useful. See
Section “Rectangles” in the Emacs Manual.
C-c C-k      Clear out the region-rectangle with spaces (picture-clear-rectangle). With
             a prefix argument, delete the text.
C-c C-w r Similar, but save rectangle contents in register r first (picture-clear-
          rectangle-to-register).       See Section “Registers” in the Emacs
          Manual.
C-c C-y      Copy last killed rectangle into the buffer by overwriting, with upper left corner
             at point (picture-yank-rectangle). With argument, insert instead.
C-c C-x r Similar, but use the rectangle in register r (picture-yank-rectangle-from-
          register).
   The picture rectangle commands C-c C-k (picture-clear-rectangle) and C-c C-w
(picture-clear-rectangle-to-register) differ from the standard rectangle commands
in that they normally clear the rectangle instead of deleting it; this is analogous with the
way C-d is changed in Picture mode.
   However, deletion of rectangles can be useful in Picture mode, so these commands delete
the rectangle if given a numeric argument. C-c C-k either with or without a numeric
argument saves the rectangle for C-c C-y.
Editing Pictures                                                                                5



   The Picture mode commands for yanking rectangles differ from the standard ones in
that they overwrite instead of inserting. This is the same way that Picture mode insertion
of other text differs from other modes. C-c C-y (picture-yank-rectangle) inserts (by
overwriting) the rectangle that was most recently killed, while C-c C-x (picture-yank-
rectangle-from-register) does likewise for the rectangle found in a specified register.

Auto Reverting Non-File Buffers
Global Auto Revert Mode normally only reverts file buffers. There are two ways to auto-
revert certain non-file buffers: by enabling Auto Revert Mode in those buffers (using M-x
auto-revert-mode); and by setting global-auto-revert-non-file-buffers to a non-nil
value. The latter enables Auto Reverting for all types of buffers for which it is implemented
(listed in the menu below).
    Like file buffers, non-file buffers should normally not revert while you are working on
them, or while they contain information that might get lost after reverting. Therefore, they
do not revert if they are modified. This can get tricky, because deciding when a non-file
buffer should be marked modified is usually more difficult than for file buffers.
    Another tricky detail is that, for efficiency reasons, Auto Revert often does not try to
detect all possible changes in the buffer, only changes that are major or easy to detect. Hence,
enabling auto-reverting for a non-file buffer does not always guarantee that all information
in the buffer is up-to-date, and does not necessarily make manual reverts useless.
    At the other extreme, certain buffers automatically revert every auto-revert-interval
seconds. (This currently only applies to the Buffer Menu.) In this case, Auto Revert does
not print any messages while reverting, even when auto-revert-verbose is non-nil.
    Some non-file buffers can be updated reliably by file notification on their default directory;
Dired buffers is an example. The major mode can indicate this by setting buffer-auto-
revert-by-notification to a non-nil value in that buffer, allowing Auto Revert to avoid
periodic polling. Such notification does not include changes to files in that directory, only to
the directory itself.
    The details depend on the particular types of buffers and are explained in the correspond-
ing sections.

Auto Reverting the Buffer Menu
If auto-reverting of non-file buffers is enabled, the Buffer Menu (see Section “Several Buffers”
in the Emacs Manual) automatically reverts every auto-revert-interval seconds, whether
there is a need for it or not. (It would probably take longer to check whether there is a need
than to actually revert.)
    If the Buffer Menu inappropriately gets marked modified, just revert it manually using
g and auto-reverting will resume. However, if you marked certain buffers to get deleted
or to be displayed, you have to be careful, because reverting erases all marks. The fact
that adding marks sets the buffer’s modified flag prevents Auto Revert from automatically
erasing the marks.

Auto Reverting Dired buffers
Dired buffers only auto-revert when the file list of the buffer’s main directory changes (e.g.,
when a new file is added or deleted). They do not auto-revert when information about a
Editing Pictures                                                                             6



particular file changes (e.g., when the size changes) or when inserted subdirectories change.
To be sure that all listed information is up to date, you have to manually revert using g, even
if auto-reverting is enabled in the Dired buffer. Sometimes, you might get the impression
that modifying or saving files listed in the main directory actually does cause auto-reverting.
This is because making changes to a file, or saving it, very often causes changes in the
directory itself; for instance, through backup files or auto-save files. However, this is not
guaranteed.
    If the Dired buffer is marked modified and there are no changes you want to protect,
then most of the time you can make auto-reverting resume by manually reverting the buffer
using g. There is one exception. If you flag or mark files, you can safely revert the buffer.
This will not erase the flags or marks (unless the marked file has been deleted, of course).
However, the buffer will stay modified, even after reverting, and auto-reverting will not
resume. This is because, if you flag or mark files, you may be working on the buffer and
you might not want the buffer to change without warning. If you want auto-reverting to
resume in the presence of marks and flags, mark the buffer non-modified using M-~. However,
adding, deleting or changing marks or flags will mark it modified again.
    Remote Dired buffers are currently not auto-reverted. Neither are Dired buffers for
which you used shell wildcards or file arguments to list only some of the files. *Find* and
*Locate* buffers do not auto-revert either.
    Note that auto-reverting Dired buffers may not work satisfactorily on some systems.
                                                                                               7



Subdirectory Switches in Dired
You can insert subdirectories with specified ls switches in Dired buffers using C-u i. You
can change the ls switches of an already inserted subdirectory at point using C-u l.
   Dired preserves the switches if you revert the buffer. Deleting a subdirectory forgets
about its switches.
   Using dired-undo (see Section “Marks vs Flags” in the Emacs Manual) to reinsert or
delete subdirectories that were inserted with explicit switches can bypass Dired’s machinery
for remembering (or forgetting) switches. Deleting a subdirectory using dired-undo does
not forget its switches. When later reinserted using i, it will be reinserted using its old
switches. Using dired-undo to reinsert a subdirectory that was deleted using the regular
Dired commands (not dired-undo) will originally insert it with its old switches. Reverting
the buffer, however, will relist it using the buffer’s default switches. If any of this yields
problems, you can easily correct the situation using C-u i or C-u l.
   Dired does not remember the R switch. Inserting a subdirectory with switches that
include the R switch is equivalent to inserting each of its subdirectories using all remaining
switches. For instance, updating or killing a subdirectory that was inserted with the R switch
will not update or kill its subdirectories.
   The buffer’s default switches do not affect subdirectories that were inserted using explicitly
specified switches. In particular, commands such as s that change the buffer’s switches do
not affect such subdirectories. (They do, however, affect subdirectories without explicitly
assigned switches.)
   You can make Dired forget about all subdirectory switches and relist all subdirectories
with the buffer’s default switches using M-x dired-reset-subdir-switches. This also
reverts the Dired buffer.
                                                                                          8

More advanced features of the Calendar and
Diary
This section describes some of the more advanced/specialized features of the calendar and
diary. It starts with some of the many ways in which you can customize the calendar and
diary to suit your personal tastes.

Customizing the Calendar
The calendar display unfortunately cannot be changed from three months, but you
can customize the whitespace used by setting the variables: calendar-left-margin,
calendar-day-header-width, calendar-day-digit-width, calendar-column-width,
and calendar-intermonth-spacing.       To display text between the months, for
example week numbers, customize the variables calendar-intermonth-header and
calendar-intermonth-text as described in their documentation.
   The variable calendar-month-header controls the text that appears above each month
in the calendar. By default, it shows the month and year. The variable calendar-day-
header-array controls the text that appears above each day’s column in every month. By
default, it shows the first two letters of each day’s name.
    The variable calendar-holiday-marker specifies how to mark a date that is a holiday.
Its value may be a single-character string to insert next to the date, or a face name to use
for displaying the date. Likewise, the variable diary-entry-marker specifies how to mark
a date that has diary entries. The function calendar-mark-today uses calendar-today-
marker to mark today’s date. By default, the calendar uses faces named holiday, diary,
and calendar-today for these purposes.
   Starting the calendar runs the normal hook calendar-initial-window-hook. Recom-
putation of the calendar display does not run this hook. But if you leave the calendar with
the q command and reenter it, the hook runs again.
   The variable calendar-today-visible-hook is a normal hook run after the calendar
buffer has been prepared with the calendar, when the current date is visible in the window.
One use of this hook is to mark today’s date; to do that use either of the functions
calendar-mark-today or calendar-star-date:
      (add-hook 'calendar-today-visible-hook 'calendar-mark-today)
A similar normal hook, calendar-today-invisible-hook is run if the current date is not
visible in the window.
   Each of the calendar cursor motion commands runs the hook calendar-move-hook after
it moves the cursor.

Customizing the Holidays
There are several variables listing the default holidays that Emacs knows about. These
are: holiday-general-holidays, holiday-local-holidays, holiday-solar-holidays,
holiday-bahai-holidays, holiday-christian-holidays, holiday-hebrew-holidays,
holiday-islamic-holidays,         holiday-oriental-holidays,     and holiday-other-
holidays. The names should be self-explanatory; e.g., holiday-solar-holidays lists sun-
and moon-related holidays.
More advanced features of the Calendar and Diary                                           9



   You can customize these lists of holidays to your own needs, deleting or adding holidays
as described below. Set any of them to nil to not show the associated holidays.
   The general holidays are, by default, holidays common throughout the United States.
In contrast, holiday-local-holidays and holiday-other-holidays are both empty by
default. These are intended for system-wide settings and your individual use, respectively.
   By default, Emacs does not include all the holidays of the religions that it knows,
only those commonly found in secular calendars. For a more extensive collection of reli-
gious holidays, you can set any (or all) of the variables calendar-bahai-all-holidays-
flag, calendar-christian-all-holidays-flag, calendar-hebrew-all-holidays-flag,
or calendar-islamic-all-holidays-flag to t.
   Each of the holiday variables is a list of holiday forms, each form describing a holiday
(or sometimes a list of holidays). Here is a table of the possible kinds of holiday form. Day
numbers and month numbers count starting from 1, but dayname numbers count Sunday as
0. The argument string is always the description of the holiday, as a string.
(holiday-fixed month day string)
          A fixed date on the Gregorian calendar.
(holiday-float month dayname k string
          &optional day) The kth dayname (dayname=0 for Sunday, and so on) after or
          before Gregorian date month, day. Negative k means count back from the end
          of the month. Optional day defaults to 1 if k is positive, and the last day of
          month otherwise.
(holiday-chinese month day string)
          A fixed date on the Chinese calendar.
(holiday-hebrew month day string)
          A fixed date on the Hebrew calendar.
(holiday-islamic month day string)
          A fixed date on the Islamic calendar.
(holiday-julian month day string)
          A fixed date on the Julian calendar.
(holiday-sexp sexp string)
          A date calculated by the Lisp expression sexp. The expression should use the
          variable year to compute and return the date of a holiday in the form of a list
          (month day year), or nil if the holiday doesn’t happen this year.
(if condition holiday-form)
          A holiday that happens only if condition is true.
(function [args])
           A list of dates calculated by the function function, called with arguments args.
   For example, suppose you want to add Bastille Day, celebrated in France on July 14 (i.e.,
the fourteenth day of the seventh month). You can do this as follows:
      (setq holiday-other-holidays '((holiday-fixed 7 14 "Bastille Day")))
More advanced features of the Calendar and Diary                                            10



   Many holidays occur on a specific day of the week, at a specific time of month. Here is a
holiday form describing Hurricane Supplication Day, celebrated in the Virgin Islands on the
fourth Monday in July:
      (holiday-float 7 1 4 "Hurricane Supplication Day")
Here the 7 specifies July, the 1 specifies Monday (Sunday is 0, Tuesday is 2, and so on), and
the 4 specifies the fourth occurrence in the month (1 specifies the first occurrence, 2 the
second occurrence, −1 the last occurrence, −2 the second-to-last occurrence, and so on).
   You can specify holidays that occur on fixed days of the Bahá’ı́, Chinese, Hebrew, Islamic,
and Julian calendars too. For example,
      (setq holiday-other-holidays
            '((holiday-hebrew 10 2 "Last day of Hanukkah")
              (holiday-islamic 3 12 "Mohammed's Birthday")
              (holiday-julian 4 2 "Jefferson's Birthday")))
adds the last day of Hanukkah (since the Hebrew months are numbered with 1 starting from
Nisan), the Islamic feast celebrating Mohammed’s birthday (since the Islamic months are
numbered from 1 starting with Muharram), and Thomas Jefferson’s birthday, which is 2
April 1743 on the Julian calendar.
   To include a holiday conditionally, use either Emacs Lisp’s if or the holiday-sexp
form. For example, American presidential elections occur on the first Tuesday after the first
Monday in November of years divisible by 4:
      (holiday-sexp '(if (zerop (% year 4))
                         (calendar-gregorian-from-absolute
                          (1+ (calendar-dayname-on-or-before
                                1 (+ 6 (calendar-absolute-from-gregorian
                                        (list 11 1 year)))))))
                    "US Presidential Election")
or
      (if (zerop (% displayed-year 4))
          (holiday-fixed 11
                 (calendar-extract-day
                   (calendar-gregorian-from-absolute
                     (1+ (calendar-dayname-on-or-before
                           1 (+ 6 (calendar-absolute-from-gregorian
                                    (list 11 1 displayed-year)))))))
                 "US Presidential Election"))
    Some holidays just don’t fit into any of these forms because special calculations are
involved in their determination. In such cases you must write a Lisp function to do the
calculation. To include eclipses, for example, add (eclipses) to holiday-other-holidays
and write an Emacs Lisp function eclipses that returns a (possibly empty) list of the
relevant Gregorian dates among the range visible in the calendar window, with descriptive
strings, like this:
      (((6 4 2012) "Lunar Eclipse") ((11 13 2012) "Solar Eclipse") ... )


Converting from the Mayan Calendar
Here are the commands to select dates based on the Mayan calendar:
gml         Move to a date specified by the long count calendar (calendar-mayan-goto-
            long-count-date).
More advanced features of the Calendar and Diary                                         11



gmnt        Move to the next occurrence of a place in the tzolkin calendar (calendar-mayan-
            next-tzolkin-date).

gmpt        Move to the previous occurrence of a place in the tzolkin calendar
            (calendar-mayan-previous-tzolkin-date).

gmnh        Move to the next occurrence of a place in the haab calendar (calendar-mayan-
            next-haab-date).

gmph        Move to the previous occurrence of a place in the haab calendar
            (calendar-mayan-previous-haab-date).

gmnc        Move to the next occurrence of a place in the calendar round (calendar-mayan-
            next-calendar-round-date).

gmpc        Move to the previous occurrence of a place in the calendar round
            (calendar-mayan-previous-calendar-round-date).

   To understand these commands, you need to understand the Mayan calendars. The long
count is a counting of days with these units:
      1 kin = 1 day 1 uinal = 20 kin 1 tun = 18 uinal
      1 katun = 20 tun 1 baktun = 20 katun
Thus, the long count date 12.16.11.16.6 means 12 baktun, 16 katun, 11 tun, 16 uinal, and 6
kin. The Emacs calendar can handle Mayan long count dates as early as 7.17.18.13.3, but
no earlier. When you use the g m l command, type the Mayan long count date with the
baktun, katun, tun, uinal, and kin separated by periods.
   The Mayan tzolkin calendar is a cycle of 260 days formed by a pair of independent cycles
of 13 and 20 days. Since this cycle repeats endlessly, Emacs provides commands to move
backward and forward to the previous or next point in the cycle. Type g m p t to go to the
previous tzolkin date; Emacs asks you for a tzolkin date and moves point to the previous
occurrence of that date. Similarly, type g m n t to go to the next occurrence of a tzolkin
date.
    The Mayan haab calendar is a cycle of 365 days arranged as 18 months of 20 days each,
followed by a 5-day monthless period. Like the tzolkin cycle, this cycle repeats endlessly,
and there are commands to move backward and forward to the previous or next point in the
cycle. Type g m p h to go to the previous haab date; Emacs asks you for a haab date and
moves point to the previous occurrence of that date. Similarly, type g m n h to go to the
next occurrence of a haab date.
    The Maya also used the combination of the tzolkin date and the haab date. This
combination is a cycle of about 52 years called a calendar round. If you type g m p c, Emacs
asks you for both a haab and a tzolkin date and then moves point to the previous occurrence
of that combination. Use g m n c to move point to the next occurrence of a combination.
These commands signal an error if the haab/tzolkin date combination you have typed is
impossible.
  Emacs uses strict completion (see Section “Completion Exit” in the Emacs Manual)
whenever it asks you to type a Mayan name, so you don’t have to worry about spelling.
More advanced features of the Calendar and Diary                                            12



Date Display Format
You can customize the way dates are displayed in the diary, mode lines, and messages
by setting calendar-date-display-form. This variable holds a list of expressions that
can involve the variables month, day, and year, which are all numbers in string form, and
monthname and dayname, which are both alphabetic strings. In the American style, the
default value of this list is as follows:
      ((if dayname (concat dayname ", ")) monthname " " day ", " year)
while in the European style this value is the default:
      ((if dayname (concat dayname ", ")) day " " monthname " " year)
The default ISO date representation is:
      ((format "%s-%.2d-%.2d" year (string-to-number month)
               (string-to-number day)))
Another typical American format is:
      (month "/" day "/" (substring year -2))


Time Display Format
The calendar and diary by default display times of day in the conventional American style
with the hours from 1 through 12, minutes, and either ‘am’ or ‘pm’. If you prefer the European
style, also known in the US as military, in which the hours go from 00 to 23, you can alter
the variable calendar-time-display-form. This variable is a list of expressions that can
involve the variables 12-hours, 24-hours, and minutes, which are all numbers in string
form, and am-pm and time-zone, which are both alphabetic strings. The default value is:
      (12-hours ":" minutes am-pm
                (if time-zone " (") time-zone (if time-zone ")"))
Here is a value that provides European style times:
      (24-hours ":" minutes
                (if time-zone " (") time-zone (if time-zone ")"))
   Note that few calendar functions return a time of day (at present, only solar functions).

Customizing the Diary
Ordinarily, the diary window indicates any holidays that fall on the date of the diary entries,
either in the mode line or the buffer itself. The process of checking for holidays can be slow,
depending on the defined holidays. In that case, setting diary-show-holidays-flag to
nil will speed up the diary display.
    The variable diary-number-of-entries controls the number of days of diary entries
to be displayed at one time. It affects the initial display when calendar-view-diary-
initially-flag is t, as well as the command M-x diary. For example, a value of 1 (the
default) displays only the current day’s diary entries, whereas a value of 2 will also show
the next day’s entries. The value can also be a vector of seven integers: for example, if the
value is [0 2 2 2 2 4 1] then no diary entries appear on Sunday, the current date’s and the
next day’s diary entries appear Monday through Thursday, Friday through Monday’s entries
appear on Friday, while on Saturday only that day’s entries appear.
    You can customize the form of dates in your diary file by setting the variable diary-date-
forms. This variable is a list of patterns for recognizing a date. Each date pattern is a list
More advanced features of the Calendar and Diary                                          13



whose elements may be regular expressions (see Section “Regular Expressions” in the Emacs
Lisp Reference Manual) or the symbols month, day, year, monthname, and dayname. All
these elements serve as patterns that match certain kinds of text in the diary file. In order
for the date pattern as a whole to match, all of its elements must match consecutively.
   A regular expression in a date pattern matches in its usual fashion, using the standard
syntax table altered so that ‘*’ is a word constituent.
   The symbols month, day, year, monthname, and dayname match the month number, day
number, year number, month name, and day name of the date being considered. The symbols
that match numbers allow leading zeros; those that match names allow capitalization and
abbreviation (as specified by calendar-month-abbrev-array and calendar-day-abbrev-
array). All the symbols can match ‘*’; since ‘*’ in a diary entry means “any day”, “any
month”, and so on, it should match regardless of the date being considered.
   The default value of diary-date-forms in the American style is provided by
diary-american-date-forms:
      ((month "/" day "[^/0-9]")
       (month "/" day "/" year "[^0-9]")
       (monthname " *" day "[^,0-9]")
       (monthname " *" day ", *" year "[^0-9]")
       (dayname "\\W"))
The variables diary-european-date-forms and diary-iso-date-forms provide other de-
fault styles.
    The date patterns in the list must be mutually exclusive and must not match any portion
of the diary entry itself, just the date and one character of whitespace. If, to be mutually
exclusive, the pattern must match a portion of the diary entry text—beyond the whitespace
that ends the date—then the first element of the date pattern must be backup. This causes
the date recognizer to back up to the beginning of the current word of the diary entry, after
finishing the match. Even if you use backup, the date pattern must absolutely not match
more than a portion of the first word of the diary entry. For example, the default value of
diary-european-date-forms is:
      ((day "/" month "[^/0-9]")
       (day "/" month "/" year "[^0-9]")
       (backup day " *" monthname "\\W+\\<\\([^*0-9]\\|\\([0-9]+[:aApP]\\)\\)")
       (day " *" monthname " *" year "[^0-9]")
       (dayname "\\W"))
Notice the use of backup in the third pattern, because it needs to match part of a word
beyond the date itself to distinguish it from the fourth pattern.

Diary Entries Using non-Gregorian Calendars
As well as entries based on the standard Gregorian calendar, your diary can have entries
based on Bahá’ı́, Chinese, Hebrew, or Islamic dates. Recognition of such entries can be
time-consuming, however, and since most people don’t use them, you must explicitly enable
their use. If you want the diary to recognize Hebrew-date diary entries, for example, you
must do this:
      (add-hook 'diary-nongregorian-listing-hook 'diary-hebrew-list-entries)
More advanced features of the Calendar and Diary                                           14



      (add-hook 'diary-nongregorian-marking-hook 'diary-hebrew-mark-entries)
Similarly, for Islamic, Bahá’ı́ and Chinese entries, add diary-islamic-list-entries
and diary-islamic-mark-entries, diary-bahai-list-entries and diary-bahai-mark-
entries, or diary-chinese-list-entries and diary-chinese-mark-entries.
   These diary entries have the same formats as Gregorian-date diary entries; except that
diary-bahai-entry-symbol (default ‘B’) must precede a Bahá’ı́ date, diary-chinese-
entry-symbol (default ‘C’) a Chinese date, diary-hebrew-entry-symbol (default ‘H’) a
Hebrew date, and diary-islamic-entry-symbol (default ‘I’) an Islamic date. Moreover,
non-Gregorian month names may not be abbreviated (because the first three letters are
often not unique). (Note also that you must use “Adar I” if you want Adar of a common
Hebrew year.) For example, a diary entry for the Hebrew date Heshvan 25 could look like
this:
      HHeshvan 25 Happy Hebrew birthday!
and would appear in the diary for any date that corresponds to Heshvan 25 on the Hebrew
calendar. And here is an Islamic-date diary entry that matches Dhu al-Qada 25:
      IDhu al-Qada 25 Happy Islamic birthday!
    As with Gregorian-date diary entries, non-Gregorian entries are nonmarking if preceded
by diary-nonmarking-symbol (default ‘&’).
    Here is a table of commands used in the calendar to create diary entries that match the
selected date and other dates that are similar in the Bahá’ı́, Chinese, Hebrew, or Islamic
calendars:
ihd         diary-hebrew-insert-entry
ihm         diary-hebrew-insert-monthly-entry
ihy         diary-hebrew-insert-yearly-entry
iid         diary-islamic-insert-entry
iim         diary-islamic-insert-monthly-entry
iiy         diary-islamic-insert-yearly-entry
iBd         diary-bahai-insert-entry
iBm         diary-bahai-insert-monthly-entry
iBy         diary-bahai-insert-yearly-entry
iCd         diary-chinese-insert-entry
iCm         diary-chinese-insert-monthly-entry
iCy         diary-chinese-insert-yearly-entry
iCa         diary-chinese-insert-anniversary-entry
   These commands work much like the corresponding commands for ordinary diary entries:
they apply to the date that point is on in the calendar window, and what they do is insert
just the date portion of a diary entry at the end of your diary file. You must then insert the
rest of the diary entry. The basic commands add an entry for the specific non-Gregorian date,
the ‘monthly’ commands for the given non-Gregorian day-within-month in every month,
and the ‘yearly’ commands for the given non-Gregorian day and month in every year.
More advanced features of the Calendar and Diary                                             15



Diary Display
Diary display works by preparing the list of diary entries and then running the function spec-
ified by the variable diary-display-function. The default value diary-fancy-display
displays diary entries and holidays by copying them into a special buffer that exists only for
the sake of display. Copying diary entries to a separate buffer provides an opportunity to
change the displayed text to make it prettier—for example, to sort the entries by the dates
they apply to.
   Ordinarily, the fancy diary buffer does not show days for which there are no diary entries,
even if that day is a holiday. If you want such days to be shown in the fancy diary buffer,
set the variable diary-list-include-blanks to t.
  The fancy diary buffer enables View mode (see Section “View Mode” in the Emacs
Manual).
    The alternative display method diary-simple-display shows the actual diary buffer,
and uses invisible text to hide entries that don’t apply. Holidays are shown in the mode
line. The advantage of this method is that you can edit the buffer and save your changes
directly to the diary file. This method is not as flexible as the fancy method, however. For
example, it cannot sort entries. Another disadvantage is that invisible text can be confusing.
For example, if you copy a region of text in order to paste it elsewhere, invisible text may
be included. Similarly, since the diary buffer as you see it is an illusion, simply printing the
buffer may not print what you see on your screen.
   For this reason, there is a special command to print hard copy of the diary buffer
as it appears; this command is M-x diary-print-entries. It works with either display
method, although with the fancy display you can also print the buffer like any other. To
print a hard copy of a day-by-day diary for a week, position point on the first day of the
week, type 7 d, and then do M-x diary-print-entries. As usual, the inclusion of the
holidays slows down the display slightly; you can speed things up by setting the variable
diary-show-holidays-flag to nil.
    This command prepares a temporary buffer that contains only the diary entries currently
visible in the diary buffer. Unlike with the simple display, the other irrelevant entries are
really absent, not just hidden. After preparing the buffer, it runs the hook diary-print-
entries-hook. The default value of this hook sends the data directly to the printer with
the command lpr-buffer (see Section “Printing” in the Emacs Manual). If you want to
use a different command to do the printing, just change the value of this hook. Other uses
might include, for example, rearranging the lines into order by day and time.
    You can edit the diary entries as they appear in the simple diary window, but it is
important to remember that the buffer displayed contains the entire diary file, with portions
of it concealed from view. This means, for instance, that the C-f (forward-char) command
can put point at what appears to be the end of the line, but what is in reality the middle of
some concealed line.
   Be careful when editing the diary entries in the simple display! Inserting additional lines
or adding/deleting characters in the middle of a visible line cannot cause problems, but
editing at the end of a line may not do what you expect. Deleting a line may delete other
invisible entries that follow it. Before editing the simple diary buffer, it is best to display
the entire file with s (diary-show-all-entries).
More advanced features of the Calendar and Diary                                             16



Fancy Diary Display
The following features only work with the fancy diary display.
   You can use the normal hook diary-list-entries-hook to sort each day’s diary entries
by their time of day. Here’s how:
      (add-hook 'diary-list-entries-hook 'diary-sort-entries t)
For each day, this sorts diary entries that begin with a recognizable time of day according
to their times. Diary entries without times come first within each day. Note how the sort
command is placed at the end of the hook list, in case earlier members of the list change the
order of the diary entries, or add items.
   You can write ‘comments’ in diary entries, by setting the variables diary-comment-start
and diary-comment-end to strings that delimit comments. The fancy display does not
print comments. You might want to put meta-data for the use of other packages (e.g., the
appointment package, see Section “Appointments” in the Emacs Manual) inside comments.
   Your main diary file can include other files. This permits a group of people to share
a diary file for events that apply to all of them. Lines in the diary file starting with
diary-include-string:
      #include "filename"
include the diary entries from the file filename in the fancy diary buffer. The include
mechanism is recursive, so that included files can include other files, and so on (you must
be careful not to have a cycle of inclusions, of course). Here is how to enable the include
facility:
      (add-hook 'diary-list-entries-hook 'diary-include-other-diary-files)
      (add-hook 'diary-mark-entries-hook 'diary-mark-included-diary-files)
   The include mechanism works only with the fancy diary display, because simple diary
display shows the entries directly from your diary file.

Sexp Entries and the Fancy Diary Display
 Sexp diary entries allow you to do more than just have complicated conditions under which a
 diary entry applies. Sexp entries should be preceded by diary-sexp-entry-symbol (default
‘%%’) in the diary file. With the fancy diary display, sexp entries can generate the text of the
 entry depending on the date itself.
    For example, an anniversary diary entry can insert the number of years since the
 anniversary date into the text of the diary entry. Thus the ‘%d’ in this diary entry:
      %%(diary-anniversary 10 31 1948) Arthur's birthday (%d years old)
gets replaced by the age, so on October 31, 1990 the entry appears in the fancy diary buffer
like this:
      Arthur's birthday (42 years old)
If the diary file instead contains this entry:
      %%(diary-anniversary 10 31 1948) Arthur's %d%s birthday
the entry in the fancy diary buffer for October 31, 1990 appears like this:
      Arthur's 42nd birthday
   Similarly, cyclic diary entries can interpolate the number of repetitions that have occurred:
      %%(diary-cyclic 50 1 1 2012) Renew medication (%d%s time)
More advanced features of the Calendar and Diary                                            17



looks like this:
      Renew medication (5th time)
in the fancy diary display on September 7, 2012.
    There is an early-reminder diary sexp that includes its entry in the diary not only on the
date of occurrence, but also on earlier dates. For example, if you want a reminder a week
before your anniversary, you can use
      %%(diary-remind '(diary-anniversary 12 22 1968) 7) Ed's anniversary
and the fancy diary will show ‘Ed's anniversary’ both on December 15 and on December
22.
    The function diary-date applies to dates described by a month, day, year combination,
each of which can be an integer, a list of integers, or t (meaning all values). For example,
      %%(diary-date '(10 11 12) 22 t) Rake leaves
causes the fancy diary to show
      Rake leaves
on October 22, November 22, and December 22 of every year.
    The function diary-float allows you to describe diary entries that apply to dates like
the third Friday of November, or the last Tuesday in April. The parameters are the month,
dayname, and an index n. The entry appears on the nth dayname after the first day of
month, where dayname=0 means Sunday, 1 means Monday, and so on. If n is negative it
counts backward from the end of month. The value of month can be a list of months, a
single month, or t to specify all months. You can also use an optional parameter day to
specify the nth dayname on or after/before day of month; the value of day defaults to 1 if n
is positive and to the last day of month if n is negative. For example,
      %%(diary-float t 1 -1) Pay rent
causes the fancy diary to show
      Pay rent
on the last Monday of every month.
    The generality of sexp diary entries lets you specify any diary entry that you can describe
algorithmically. A sexp diary entry contains an expression that computes whether the entry
applies to any given date. If its value is non-nil, the entry applies to that date; otherwise,
it does not. The expression can use the variable date to find the date being considered; its
value is a list (month day year) that refers to the Gregorian calendar.
    The sexp diary entry applies to a date when the expression’s value is non-nil, but some
values have more specific meanings. If the value is a string, that string is a description of
the event which occurs on that date. The value can also have the form (mark . string);
then mark specifies how to mark the date in the calendar, and string is the description of
the event. If mark is a single-character string, that character appears next to the date in
the calendar. If mark is a face name, the date is displayed in that face. If mark is nil, that
specifies no particular highlighting for the date.
    Suppose you get paid on the 21st of the month if it is a weekday, and on the Friday
before if the 21st is on a weekend. Here is how to write a sexp diary entry that matches
those dates:
      &%%(let ((dayname (calendar-day-of-week date))
               (day (cadr date)))
More advanced features of the Calendar and Diary                                           18



            (or (and (= day 21) (memq dayname '(1 2 3 4 5)))
                (and (memq day '(19 20)) (= dayname 5)))
               ) Pay check deposited
   The following sexp diary entries take advantage of the ability (in the fancy diary display)
to concoct diary entries whose text varies based on the date:
%%(diary-sunrise-sunset)
          Make a diary entry for today’s local times of sunrise and sunset.
%%(diary-lunar-phases)
          Make a diary entry for the phases (quarters) of the moon.
%%(diary-day-of-year)
          Make a diary entry with today’s day number in the current year and the number
          of days remaining in the current year.
%%(diary-iso-date)
          Make a diary entry with today’s equivalent ISO commercial date.
%%(diary-julian-date)
          Make a diary entry with today’s equivalent Julian calendar date.
%%(diary-astro-day-number)
          Make a diary entry with today’s equivalent astronomical (Julian) day number.
%%(diary-bahai-date)
          Make a diary entry with today’s equivalent Bahá’ı́ calendar date.
%%(diary-chinese-date)
          Make a diary entry with today’s equivalent Chinese calendar date.
%%(diary-coptic-date)
          Make a diary entry with today’s equivalent Coptic calendar date.
%%(diary-ethiopic-date)
          Make a diary entry with today’s equivalent Ethiopic calendar date.
%%(diary-french-date)
          Make a diary entry with today’s equivalent date on the French Revolutionary
          calendar.
%%(diary-hebrew-date)
          Make a diary entry with today’s equivalent Hebrew calendar date.
%%(diary-islamic-date)
          Make a diary entry with today’s equivalent Islamic calendar date.
%%(diary-mayan-date)
          Make a diary entry with today’s equivalent Mayan calendar date.
%%(diary-persian-date)
          Make a diary entry with today’s equivalent Persian calendar date.
For example, including the diary entry
      &%%(diary-hebrew-date)
More advanced features of the Calendar and Diary                                           19



 causes every day’s diary display to contain the equivalent date on the Hebrew calendar,
 if you are using the fancy diary display. (With simple diary display, the literal line
‘&%%(diary-hebrew-date)’ appears in the diary for any date.)
     This function has been used to construct certain standard Hebrew sexp diary entries:
%%(diary-hebrew-rosh-hodesh)
          Make a diary entry that tells the occurrence and ritual announcement of each
          new Hebrew month.
%%(diary-hebrew-parasha)
          Make a Saturday diary entry that tells the weekly synagogue scripture reading.
%%(diary-hebrew-sabbath-candles)
          Make a Friday diary entry that tells the local time of Sabbath candle lighting.
%%(diary-hebrew-omer)
          Make a diary entry that gives the omer count, when appropriate.
%%(diary-hebrew-yahrzeit month day year) name
          Make a diary entry marking the anniversary of a date of death. The date is the
          Gregorian (civil) date of death. The diary entry appears on the proper Hebrew
          calendar anniversary and on the day before. (The order of the parameters
          changes according to the calendar date style; for example in the European style
          to day, month, year.)
%%(diary-hebrew-birthday month day year)
          Make a diary entry for a birthday on the Hebrew calendar.
   All the functions documented above take an optional argument mark which specifies how
to mark the date in the calendar display. If one of these functions decides that it applies to
a certain date, it returns a value that contains mark, as described above.
                                                                                          20



Merging Files with Emerge
It’s not unusual for programmers to get their signals crossed and modify the same program in
two different directions. To recover from this confusion, you need to merge the two versions.
Emerge makes this easier. For other ways to compare files, see Section “Comparing Files”
in the Emacs Manual, and Section “Ediff” in The Ediff Manual.

Overview of Emerge
To start Emerge, run one of these four commands:
M-x emerge-files
          Merge two specified files.
M-x emerge-files-with-ancestor
          Merge two specified files, with reference to a common ancestor.
M-x emerge-buffers
          Merge two buffers.
M-x emerge-buffers-with-ancestor
          Merge two buffers with reference to a common ancestor in a third buffer.
   The Emerge commands compare two files or buffers, and display the comparison in
three buffers: one for each input text (the A buffer and the B buffer), and one (the merge
buffer) where merging takes place. The merge buffer shows the full merged text, not just
the differences. Wherever the two input texts differ, you can choose which one of them to
include in the merge buffer.
   The Emerge commands that take input from existing buffers use only the accessible
portions of those buffers, if they are narrowed. See Section “Narrowing” in the Emacs
Manual.
   If a common ancestor version is available, from which the two texts to be merged were
both derived, Emerge can use it to guess which alternative is right. Wherever one current
version agrees with the ancestor, Emerge presumes that the other current version is a
deliberate change which should be kept in the merged version. Use the ‘with-ancestor’
commands if you want to specify a common ancestor text. These commands read three file
or buffer names—variant A, variant B, and the common ancestor.
  After the comparison is done and the buffers are prepared, the interactive merging starts.
You control the merging by typing special merge commands in the merge buffer (see [Merge
Commands], page 22). For each run of differences between the input texts, you can choose
which one of them to keep, or edit them both together.
   The merge buffer uses a special major mode, Emerge mode, with commands for making
these choices. But you can also edit the buffer with ordinary Emacs commands.
   At any given time, the attention of Emerge is focused on one particular difference, called
the selected difference. This difference is marked off in the three buffers like this:
      vvvvvvvvvvvvvvvvvvvv
      text that differs
      ^^^^^^^^^^^^^^^^^^^^
Merging Files with Emerge                                                                     21



Emerge numbers all the differences sequentially and the mode line always shows the number
of the selected difference.
    Normally, the merge buffer starts out with the A version of the text. But when the
A version of a difference agrees with the common ancestor, then the B version is initially
preferred for that difference.
    Emerge leaves the merged text in the merge buffer when you exit. At that point, you
can save it in a file with C-x C-w. If you give a numeric argument to emerge-files or
emerge-files-with-ancestor, it reads the name of the output file using the minibuffer.
(This is the last file name those commands read.) Then exiting from Emerge saves the
merged text in the output file.
    Normally, Emerge commands save the output buffer in its file when you exit. If you
abort Emerge with C-], the Emerge command does not save the output buffer, but you can
save it yourself if you wish.

Submodes of Emerge
 You can choose between two modes for giving merge commands: Fast mode and Edit mode.
 In Fast mode, basic merge commands are single characters, but ordinary Emacs commands
 are disabled. This is convenient if you use only merge commands. In Edit mode, all merge
 commands start with the prefix key C-c C-c, and the normal Emacs commands are also
 available. This allows editing the merge buffer, but slows down Emerge operations.
    Use e to switch to Edit mode, and C-c C-c f to switch to Fast mode. The mode line
 indicates Edit and Fast modes with ‘E’ and ‘F’.
    Emerge has two additional submodes that affect how particular merge commands work:
Auto Advance mode and Skip Prefers mode.
    If Auto Advance mode is in effect, the a and b commands advance to the next difference.
This lets you go through the merge faster as long as you simply choose one of the alternatives
 from the input. The mode line indicates Auto Advance mode with ‘A’.
    If Skip Prefers mode is in effect, the n and p commands skip over differences in states
“prefer-A” and “prefer-B” (see [State of Difference], page 21). Thus you see only differences
 for which neither version is presumed correct. The mode line indicates Skip Prefers mode
with ‘S’. This mode is only relevant when there is an ancestor.
    Use the command s a (emerge-auto-advance) to set or clear Auto Advance mode. Use
 s s (emerge-skip-prefers) to set or clear Skip Prefers mode. These commands turn on
 the mode with a positive argument, turn it off with a negative or zero argument, and toggle
 the mode with no argument.

State of a Difference
In the merge buffer, a difference is marked with lines of ‘v’ and ‘^’ characters. Each difference
has one of these seven states:
A           The difference is showing the A version. The a command always produces this
            state; the mode line indicates it with ‘A’.
B           The difference is showing the B version. The b command always produces this
            state; the mode line indicates it with ‘B’.
Merging Files with Emerge                                                                   22



default-A
default-B   The difference is showing the A or the B state by default, because you haven’t
            made a choice. All differences start in the default-A state (and thus the merge
            buffer is a copy of the A buffer), except those for which one alternative is
            preferred (see below).
            When you select a difference, its state changes from default-A or default-B to
            plain A or B. Thus, the selected difference never has state default-A or default-B,
            and these states are never displayed in the mode line.
            The command d a chooses default-A as the default state, and d b chooses default-
            B. This chosen default applies to all differences that you have never selected
            and for which no alternative is preferred. If you are moving through the merge
            sequentially, the differences you haven’t selected are those following the selected
            one. Thus, while moving sequentially, you can effectively make the A version
            the default for some sections of the merge buffer and the B version the default
            for others by using d a and d b between sections.
prefer-A
prefer-B    The difference is showing the A or B state because it is preferred. This means
            that you haven’t made an explicit choice, but one alternative seems likely to
            be right because the other alternative agrees with the common ancestor. Thus,
            where the A buffer agrees with the common ancestor, the B version is preferred,
            because chances are it is the one that was actually changed.
            These two states are displayed in the mode line as ‘A*’ and ‘B*’.
combined    The difference is showing a combination of the A and B states, as a result of the
            x c or x C commands.
            Once a difference is in this state, the a and b commands don’t do anything to it
            unless you give them a numeric argument.
            The mode line displays this state as ‘comb’.

Merge Commands
Here are the Merge commands for Fast mode; in Edit mode, precede them with C-c C-c:
p           Select the previous difference.
n           Select the next difference.
a           Choose the A version of this difference.
b           Choose the B version of this difference.
C-u n j     Select difference number n.
.           Select the difference containing point.
q           Quit—finish the merge.
C-]         Abort—exit merging and do not save the output.
f           Go into Fast mode. (In Edit mode, this is actually C-c C-c f.)
e           Go into Edit mode.
Merging Files with Emerge                                                                  23



l           Recenter (like C-l) all three windows. With an argument, reestablish the default
            three-window display.
-           Specify part of a prefix numeric argument.
digit       Also specify part of a prefix numeric argument.
da          Choose the A version as the default from here down in the merge buffer.
db          Choose the B version as the default from here down in the merge buffer.
ca          Copy the A version of this difference into the kill ring.
cb          Copy the B version of this difference into the kill ring.
ia          Insert the A version of this difference at point.
ib          Insert the B version of this difference at point.
m           Put point and mark around the difference.
^           Scroll all three windows down (like M-v).
v           Scroll all three windows up (like C-v).
<           Scroll all three windows left (like C-x <).
>           Scroll all three windows right (like C-x >).
|           Reset horizontal scroll on all three windows.
x1          Shrink the merge window to one line. (Use C-u l to restore it to full size.)
xc          Combine the two versions of this difference (see [Combining in Emerge], page 24).
xf          Show the names of the files/buffers Emerge is operating on, in a Help window.
            (Use C-u l to restore windows.)
xj          Join this difference with the following one. (C-u x j joins this difference with
            the previous one.)
xs          Split this difference into two differences. Before you use this command, position
            point in each of the three buffers at the place where you want to split the
            difference.
xt          Trim identical lines off the top and bottom of the difference. Such lines occur
            when the A and B versions are identical but differ from the ancestor version.

Exiting Emerge
The q command (emerge-quit) finishes the merge, storing the results into the output file if
you specified one. It restores the A and B buffers to their proper contents, or kills them if
they were created by Emerge and you haven’t changed them. It also disables the Emerge
commands in the merge buffer, since executing them later could damage the contents of the
various buffers.
    C-] aborts the merge. This means exiting without writing the output file. If you didn’t
specify an output file, then there is no real difference between aborting and finishing the
merge.
    If the Emerge command was called from another Lisp program, then its return value is t
for successful completion, or nil if you abort.
Merging Files with Emerge                                                                  24



Combining the Two Versions
Sometimes you want to keep both alternatives for a particular difference. To do this, use x
c, which edits the merge buffer like this:
      #ifdef NEW
      version from B buffer
      #else /* not NEW */
      version from A buffer
      #endif /* not NEW */
While this example shows C preprocessor conditionals delimiting the two alternative versions,
you can specify the strings to use by setting the variable emerge-combine-versions-
template to a string of your choice. In the string, ‘%a’ says where to put version A, and ‘%b’
says where to put version B. The default setting, which produces the results shown above,
looks like this:
      "#ifdef NEW\n%b#else /* not NEW */\n%a#endif /* not NEW */\n"

Fine Points of Emerge
During the merge, you mustn’t try to edit the A and B buffers yourself. Emerge modifies
them temporarily, but ultimately puts them back the way they were.
   You can have any number of merges going at once—just don’t use any one buffer as input
to more than one merge at once, since the temporary changes made in these buffers would
get in each other’s way.
   Starting Emerge can take a long time because it needs to compare the files fully. Emacs
can’t do anything else until diff finishes. Perhaps in the future someone will change Emerge
to do the comparison in the background when the input files are large—then you could keep
on doing other things with Emacs until Emerge is ready to accept commands.
   After setting up the merge, Emerge runs the hook emerge-startup-hook. See Section
“Hooks” in the Emacs Manual.
                                                                                            25



Advanced VC Usage
Commonly used features of Emacs’s version control (VC) support are described in the main
Emacs manual (see Section “Version Control” in the Emacs Manual). This chapter describes
more advanced VC usage.

Miscellaneous Commands and Features of VC
This section explains the less-frequently-used features of VC.

Change Logs and VC
If you use RCS or CVS for a program with a ChangeLog file (see Section “Change Log” in
the Emacs Manual), you can generate change log entries from the version control log entries
of previous commits.
    Note that this only works with RCS or CVS. This procedure would be particularly incor-
rect on a modern changeset-based version control system, where changes to the ChangeLog
file would normally be committed as part of a changeset. In that case, you should write the
change log entries first, then pull them into the ‘*vc-log*’ buffer when you commit (see
Section “Log Buffer” in the Emacs Manual).
C-x v a       Visit the current directory’s ChangeLog file and, for registered files in that
              directory, create new entries for versions committed since the most recent change
              log entry (vc-update-change-log).
C-u C-x v a
              As above, but only find entries for the current buffer’s file.
    For example, suppose the first line of ChangeLog is dated 1999-04-10, and that the only
 check-in since then was by Nathaniel Bowditch to rcs2log on 1999-05-22 with log entry
‘Ignore log messages that start with '#'.’. Then C-x v a inserts this ChangeLog entry:
      1999-05-22    Nathaniel Bowditch   <nat@apn.org>

                * rcs2log: Ignore log messages that start with '#'.

 If the version control log entry specifies a function name (in parenthesis at the beginning of
 a line), that is reflected in the ChangeLog entry. For example, if a log entry for vc.el is
‘(vc-do-command): Check call-process status.’, the ChangeLog entry is:
      1999-05-06    Nathaniel Bowditch   <nat@apn.org>

                * vc.el (vc-do-command): Check call-process status.

   When C-x v a adds several change log entries at once, it groups related log entries
together if they all are checked in by the same author at nearly the same time. If the log
entries for several such files all have the same text, it coalesces them into a single entry.

Deleting and Renaming Version-Controlled Files
M-x vc-delete-file
          Prompt for a file name, delete the file from the working tree, and schedule the
          deletion for committing.
Advanced VC Usage                                                                            26



M-x vc-rename-file
          Prompt for two file names, old and new, rename them in the working tree,
          and schedule the renaming for committing. The old file defaults to the current
          buffer’s file name if it is under VC.
    If you wish to delete a version-controlled file, use the command M-x vc-delete-file.
This prompts for the file name, and deletes it via the version control system. The file is
removed from the working tree, and in the VC Directory buffer (see Section “VC Directory
Mode” in the Emacs Manual), it is displayed with the ‘removed’ status. When you commit
it, the deletion takes effect in the repository.
   To rename a version-controlled file, type M-x vc-rename-file. This prompts for two
arguments: the name of the file you wish to rename, and the new name; then it performs
the renaming via the version control system. The renaming takes effect immediately in the
working tree, and takes effect in the repository when you commit the renamed file.
    On modern version control systems that have built-in support for renaming, the renamed
file retains the full change history of the original file. On CVS and older version control
systems, the vc-rename-file command actually works by creating a copy of the old file
under the new name, registering it, and deleting the old file. In this case, the change history
is not preserved.

Revision Tags
Most version control systems allow you to apply a revision tag to a specific version of a
version-controlled tree. On modern changeset-based version control systems, a revision tag
is simply a symbolic name for a particular revision. On older file-based systems like CVS,
each tag is added to the entire set of version-controlled files, allowing them to be handled as
a unit. Revision tags are commonly used to identify releases that are distributed to users.
   There are two basic commands for tags; one makes a tag with a given name, the other
retrieves a named tag.
C-x v s name RET
           Define the working revision of every registered file in or under the current
           directory as a tag named name (vc-create-tag).
C-x v r name RET
           For all registered files at or below the current directory level, retrieve the tagged
           revision name. This command will switch to a branch if name is a branch name
           and your VCS distinguishes branches from tags. (vc-retrieve-tag).
            This command reports an error if any files are locked at or below the current
            directory, without changing anything; this is to avoid overwriting work in
            progress.
   You can give a tag or branch name as an argument to C-x v = or C-x v ~ (see Section
“Old Revisions” in the Emacs Manual). Thus, you can use it to compare a tagged version
against the current files, or two tagged versions against each other.
   On SCCS, VC implements tags itself; these tags are visible only through VC. Most later
systems (including CVS, Subversion, bzr, git, and hg) have a native tag facility, and VC
uses it where available; those tags will be visible even when you bypass VC.
Advanced VC Usage                                                                          27



   In file-based version control systems, when you rename a registered file you need to
rename its master along with it; the command vc-rename-file will do this automatically
(see Section “VC Delete/Rename” in the Emacs Manual). If you are using SCCS, you must
also update the records of the tag, to mention the file by its new name (vc-rename-file
does this, too). An old tag that refers to a master file that no longer exists under the
recorded name is invalid; VC can no longer retrieve it. It would be beyond the scope of this
manual to explain enough about RCS and SCCS to explain how to update the tags by hand.
Using vc-rename-file makes the tag remain valid for retrieval, but it does not solve all
problems. For example, some of the files in your program probably refer to others by name.
At the very least, the makefile probably mentions the file that you renamed. If you retrieve
an old tag, the renamed file is retrieved under its new name, which is not the name that the
makefile expects. So the program won’t really work as retrieved.

Inserting Version Control Headers
On Subversion, CVS, RCS, and SCCS, you can put certain special strings called version
headers into a work file. When the file is committed, the version control system automatically
puts the revision number, the name of the user who made the commit, and other relevant
information into the version header.
   VC does not normally use the information in the version headers. As an exception, when
using RCS, Emacs uses the version header, if there is one, to determine the file version,
since it is often more reliable than the RCS master file. To inhibit using the version header
this way, change the variable vc-consult-headers to nil. VC then always uses the file
permissions (if it is supposed to trust them), or else checks the master file.
   To insert a suitable header string into the current buffer, use the command M-x vc-
insert-headers. This command works only on Subversion, CVS, RCS, and SCCS. The
variable vc-backend-header contains the list of keywords to insert into the version header;
for instance, CVS uses vc-cvs-header, whose default value is '("\$Id\$"). (The extra
backslashes prevent the string constant from being interpreted as a header, if the Emacs
Lisp file defining it is maintained with version control.) The vc-insert-headers command
inserts each keyword in the list on a new line at point, surrounded by tabs, and inside
comment delimiters if necessary.
   The variable vc-static-header-alist specifies further strings to add based on the
name of the buffer. Its value should be a list of elements of the form (regexp . format).
Whenever regexp matches the buffer name, format is also inserted as part of the version
header. A ‘%s’ in format is replaced with the file’s version control type.

Editing VC Commands
You can use the C-x v ! (vc-edit-next-command) prefix command to edit the shell command
line that VC is about to run. This is primarily intended to make it possible to add optional
command-line arguments to VCS commands without unnecessary complications of the VC
command set and its interfaces with the backend.
   For example, Git can produce logs of more than one branch, but C-x v b l (vc-print-
branch-log) prompts for the name of just one branch. To obtain a log of more than one
branch, you can type C-x v ! C-x v b l and then append the names of additional branches
to the end of the ‘git log’ command that VC is about to run.
Advanced VC Usage                                                                             28



Preparing Patches
When collaborating on projects it is common to send patches via email, to share changes.
You can do this using VC with the vc-prepare-patch command. This will prompt you for
the revisions you wish to share, and which destination email address(es) to use. Separate
the revisions using the value of crm-separator, commas by default. The command will then
prepare those revisions using your MUA (Mail User Agent) for you to review and send.
   When invoked interactively in a Log View buffer with marked revisions, those marked
revisions will be used.
    Depending on the value of the user option vc-prepare-patches-separately,
vc-prepare-patch will generate one or more messages. The default value t means prepare
and display a message for each revision, one after another. A value of nil means to generate
a single message with all patches attached in the body.
   If you expect to contribute patches on a regular basis, you can set the user option
vc-default-patch-addressee to the address(es) you wish to use. This will be used as the
default value when invoking vc-prepare-patch. Project maintainers may consider setting
this as a directory local variable (see hundefinedi [Directory Variables], page hundefinedi).


Customizing VC
The variable vc-handled-backends determines which version control systems VC should
handle. The default value is (RCS CVS SVN SCCS SRC Bzr Git Hg), so it contains all the
version systems that are currently supported. If you want VC to ignore one or more of these
systems, exclude its name from the list. To disable VC entirely, set this variable to nil.
    The order of systems in the list is significant: when you visit a file registered in more than
one system, VC uses the system that comes first in vc-handled-backends by default. The
order is also significant when you register a file for the first time (see Section “Registering”
in the Emacs Manual).

General Options
Emacs normally does not save backup files for source files that are maintained with version
control. If you want to make backup files even for files that use version control, set the
variable vc-make-backup-files to a non-nil value.
    Editing a version-controlled file through a symbolic link may cause unexpected results,
if you are unaware that the underlying file is version-controlled. The variable vc-follow-
symlinks controls what Emacs does if you try to visit a symbolic link pointing to a
version-controlled file. If the value is ask (the default), Emacs asks for confirmation. If it is
nil, Emacs just displays a warning message. If it is t, Emacs automatically follows the link
and visits the real file instead.
   If vc-suppress-confirm is non-nil, then C-x v v and C-x v i can save the current
buffer without asking, and C-x v u also operates without asking for confirmation.
   VC mode does much of its work by running the shell commands for the appropriate
version control system. If vc-command-messages is non-nil, VC displays messages to
indicate which shell commands it runs, and additional messages when the commands finish.
Advanced VC Usage                                                                          29



Options for RCS and SCCS
By default, RCS uses locking to coordinate the activities of several users, but there is a
mode called non-strict locking in which you can check-in changes without locking the file
first. Use ‘rcs -U’ to switch to non-strict locking for a particular file, see the rcs manual
page for details.
    When deducing the version control state of an RCS file, VC first looks for an RCS version
header string in the file (see [Version Headers], page 27). If there is no header string, VC
normally looks at the file permissions of the work file; this is fast. But there might be
situations when the file permissions cannot be trusted. In this case the master file has to be
consulted, which is rather expensive. Also the master file can only tell you if there’s any
lock on the file, but not whether your work file really contains that locked version.
   You can tell VC not to use version headers to determine the file status by setting
vc-consult-headers to nil. VC then always uses the file permissions (if it is supposed to
trust them), or else checks the master file.
   VC determines the version control state of files under SCCS much as with RCS. It does
not consider SCCS version headers, though. Thus, the variable vc-consult-headers does
not affect SCCS use.

Options specific for CVS
You can specify additional command line options to pass to all CVS operations in the
variable vc-cvs-global-switches. These switches are inserted immediately after the cvs
command, before the name of the operation to invoke.
    When using a CVS repository on a remote machine, VC can try keeping network
interactions to a minimum. This is controlled by the variable vc-cvs-stay-local. If
vc-cvs-stay-local is only-file (the default), VC determines the version control status
of each file using only the entry in the local CVS subdirectory and the information returned
by previous CVS commands. As a consequence, if you have modified a file and somebody
else has checked in other changes, you will not be notified of the conflict until you try to
commit.
   If you change vc-cvs-stay-local to nil, VC queries the remote repository before it
decides what to do in vc-next-action (C-x v v), just as it does for local repositories.
   You can also set vc-cvs-stay-local to a regular expression that is matched against the
repository host name; VC then stays local only for repositories from hosts that match the
pattern.
    When using a remote repository, Emacs normally makes automatic version backups of
the original versions of each edited file. These local backups are made whenever you save the
first changes to a file, and they are removed after you commit your changes to the repository.
(Note that these are not the same as ordinary Emacs backup files; see Section “Backup” in
the Emacs Manual.) Commands like C-x v = and C-x v u make use of automatic version
backups, if possible, to avoid having to access the network.
   Setting vc-cvs-stay-local to nil disables the making of automatic version backups.
   Automatic version backups have names of the form file.~version.~. This is similar
to the name that C-x v ~ saves old versions to (see Section “Old Revisions” in the Emacs
Manual), except for the additional dot (‘.’) after the version. The relevant VC commands
Advanced VC Usage                                                                        30



can use both kinds of version backups. The main difference is that the manual version
backups made by C-x v ~ are not deleted automatically when you commit.
   CVS does not use locking by default, but there are ways to enable locking-like behavior
using its CVSREAD or watch feature; see the CVS documentation for details. If that case, you
can use C-x v v in Emacs to toggle locking, as you would for a locking-based version control
system (see Section “VC With A Locking VCS” in the Emacs Manual).
                                                                                            31



Fortran Mode
 Fortran mode is meant for editing fixed form (and also tab format) source code (normally
 Fortran 77). For editing more modern free-form source code (Fortran 90, 95, 2003, 2008),
 use F90 mode (f90-mode). Emacs normally uses Fortran mode for files with extension ‘.f’,
‘.F’ or ‘.for’, and F90 mode for the extensions ‘.f90’, ‘.f95’, ‘.f03’ and ‘.f08’. Customize
 auto-mode-alist to add more extensions. GNU Fortran supports both free and fixed form.
 This manual mainly documents Fortran mode, but the corresponding F90 mode features are
 mentioned when relevant.
    Fortran mode provides special motion commands for Fortran statements and subprograms,
and indentation commands that understand Fortran conventions of nesting, line numbers
and continuation statements. Fortran mode has support for Auto Fill mode that breaks long
lines into proper Fortran continuation lines. Fortran mode also supports Hideshow minor
mode (see Section “Hideshow” in the Emacs Manual), and Imenu (see Section “Imenu” in
the Emacs Manual).
   Special commands for comments are provided because Fortran comments are unlike
those of other languages. Built-in abbrevs optionally save typing when you insert Fortran
keywords.
   Use M-x fortran-mode to switch to this major mode. This command runs the hook
fortran-mode-hook. See Section “Hooks” in the Emacs Manual.

Motion Commands
In addition to the normal commands for moving by and operating on defuns (Fortran
subprograms—functions and subroutines, as well as modules for F90 mode, using the com-
mands fortran-end-of-subprogram and fortran-beginning-of-subprogram), Fortran
mode provides special commands to move by statements and other program units.
C-c C-n     Move to the beginning of the                next   statement     (fortran-next-
            statement/f90-next-statement).
C-c C-p     Move to the beginning of the previous statement (fortran-previous-
            statement/f90-previous-statement). If there is no previous statement (i.e.,
            if called from the first statement in the buffer), move to the start of the buffer.
C-c C-e     Move point forward to the start of the next code block, or the end of the current
            one, whichever comes first (f90-next-block). A code block is a subroutine,
            if–endif statement, and so forth. This command exists for F90 mode only, not
            Fortran mode. With a numeric argument, it moves forward that many blocks.
C-c C-a     Move point backward to the previous block (f90-previous-block). This is like
            f90-next-block, but moves backwards.
C-M-n       Move to the end of the current code block (fortran-end-of-block/f90-end-
            of-block). With a numeric argument, move forward that number of blocks.
            The mark is set before moving point. The F90 mode version of this command
            checks for consistency of block types and labels (if present), but it does not
            check the outermost block since that may be incomplete.
Fortran Mode                                                                                   32



C-M-p        Move to the start of the current code block (fortran-beginning-of-
             block/f90-beginning-of-block). This is like fortran-end-of-block, but
             moves backwards.
   The commands fortran-beginning-of-subprogram and fortran-end-of-subprogram
move to the start or end of the current subprogram, respectively. The commands
fortran-mark-do and fortran-mark-if mark the end of the current do or if block, and
move point to the start.

Fortran Indentation
Special commands and features are needed for indenting fixed (or tab) form Fortran code in
order to make sure various syntactic entities (line numbers, comment line indicators and
continuation line flags) appear in the required columns.

Fortran Indentation and Filling Commands
C-M-j        Break the current line at point and set up a continuation line (fortran-split-
             line).
M-^          Join this line to the previous line (fortran-join-line).
C-M-q        Indent all the lines of the subprogram that point is in (fortran-indent-
             subprogram).
M-q          Fill a comment block or statement (using fortran-fill-paragraph or
             fortran-fill-statement).
    The key C-M-q runs fortran-indent-subprogram, a command to reindent all the lines
of the Fortran subprogram (function or subroutine) containing point.
   The key C-M-j runs fortran-split-line, which splits a line in the appropriate fashion
for Fortran. In a non-comment line, the second half becomes a continuation line and is
indented accordingly. In a comment line, both halves become separate comment lines.
   M-^ or C-c C-d run the command fortran-join-line, which joins a continuation line
back to the previous line, roughly as the inverse of fortran-split-line. The point must
be on a continuation line when this command is invoked.
   M-q in Fortran mode fills the comment block or statement that point is in. This removes
any excess statement continuations.

Continuation Lines
Most Fortran 77 compilers allow two ways of writing continuation lines. If the first non-space
character on a line is in column 5, then that line is a continuation of the previous line. We call
this fixed form. (In GNU Emacs we always count columns from 0; but note that the Fortran
standard counts from 1. You can customize the variable column-number-indicator-zero-
based to make the column display Fortran-like; see Section “Optional Mode Line” in the
Emacs Manual.) The variable fortran-continuation-string specifies what character to
put in column 5. A line that starts with a tab character followed by any digit except ‘0’ is
also a continuation line. We call this style of continuation tab format. (Fortran 90 introduced
free-form continuation lines.)
Fortran Mode                                                                               33



     Fortran mode can use either style of continuation line. When you enter Fortran mode, it
 tries to deduce the proper continuation style automatically from the buffer contents. It does
 this by scanning up to fortran-analyze-depth (default 100) lines from the start of the
 buffer. The first line that begins with either a tab character or six spaces determines the
 choice. If the scan fails (for example, if the buffer is new and therefore empty), the value
 of fortran-tab-mode-default (nil for fixed form, and non-nil for tab format) is used.
‘/t’ (fortran-tab-mode-string) in the mode line indicates tab format is selected. Fortran
 mode sets the value of indent-tabs-mode accordingly.
   If the text on a line starts with the Fortran continuation marker ‘$’, or if it begins with
any non-whitespace character in column 5, Fortran mode treats it as a continuation line.
When you indent a continuation line with TAB, it converts the line to the current continuation
style. When you split a Fortran statement with C-M-j, the continuation marker on the
newline is created according to the continuation style.
   The setting of continuation style affects several other aspects of editing in Fortran mode.
In fixed form mode, the minimum column number for the body of a statement is 6. Lines
inside of Fortran blocks that are indented to larger column numbers must use only the
space character for whitespace. In tab format mode, the minimum column number for the
statement body is 8, and the whitespace before column 8 must consist of one tab character.

Line Numbers
If a number is the first non-whitespace in the line, Fortran indentation assumes it is a line
number and moves it to columns 0 through 4. (Columns always count from 0 in Emacs,
but setting column-number-indicator-zero-based to nil can change that, see Section
“Optional Mode Line” in the Emacs Manual.)
   Line numbers of four digits or less are normally indented one space. The variable
fortran-line-number-indent controls this; it specifies the maximum indentation a line
number can have. The default value of the variable is 1. Fortran mode tries to prevent line
number digits passing column 4, reducing the indentation below the specified maximum if
necessary. If fortran-line-number-indent has the value 5, line numbers are right-justified
to end in column 4.
   Simply inserting a line number is enough to indent it according to these rules. As each
digit is inserted, the indentation is recomputed. To turn off this feature, set the variable
fortran-electric-line-number to nil.

Syntactic Conventions
Fortran mode assumes that you follow certain conventions that simplify the task of under-
standing a Fortran program well enough to indent it properly:
  • Two nested ‘do’ loops never share a ‘continue’ statement.
  • Fortran keywords such as ‘if’, ‘else’, ‘then’, ‘do’ and others are written without
    embedded whitespace or line breaks.
     Fortran compilers generally ignore whitespace outside of string constants, but Fortran
     mode does not recognize these keywords if they are not contiguous. Constructs such as
    ‘else if’ or ‘end do’ are acceptable, but the second word should be on the same line as
     the first and not on a continuation line.
Fortran Mode                                                                             34



If you fail to follow these conventions, the indentation commands may indent some lines
unaesthetically. However, a correct Fortran program retains its meaning when reindented
even if the conventions are not followed.

Variables for Fortran Indentation
Several additional variables control how Fortran indentation works:
fortran-do-indent
          Extra indentation within each level of ‘do’ statement (default 3).
fortran-if-indent
          Extra indentation within each level of ‘if’, ‘select case’, or ‘where’ statements
          (default 3).
fortran-structure-indent
          Extra indentation within each level of ‘structure’, ‘union’, ‘map’, or ‘interface’
          statements (default 3).
fortran-continuation-indent
          Extra indentation for bodies of continuation lines (default 5).
fortran-check-all-num-for-matching-do
           In Fortran 77, a numbered ‘do’ statement is terminated by any statement with
           a matching line number. It is common (but not compulsory) to use a ‘continue’
           statement for this purpose. If this variable has a non-nil value, indenting any
           numbered statement must check for a ‘do’ that ends there. If you always end
          ‘do’ statements with a ‘continue’ line (or if you use the more modern ‘enddo’),
           then you can speed up indentation by setting this variable to nil (the default).
fortran-blink-matching-if
          If this is t, indenting an ‘endif’ (or ‘enddo’) statement moves the cursor
          momentarily to the matching ‘if’ (or ‘do’) statement to show where it is. The
          default is nil.
fortran-minimum-statement-indent-fixed
          Minimum indentation for Fortran statements when using fixed form continuation
          line style. Statement bodies are never indented by less than this. The default is
          6.
fortran-minimum-statement-indent-tab
          Minimum indentation for Fortran statements for tab format continuation line
          style. Statement bodies are never indented by less than this. The default is 8.
   The following section describes the variables controlling the indentation of comments.

Fortran Comments
The usual Emacs comment commands assume that a comment can follow a line of code.
In Fortran 77, the standard comment syntax requires an entire line to be just a comment.
Therefore, Fortran mode replaces the standard Emacs comment commands and defines some
new variables.
Fortran Mode                                                                             35



   Fortran mode can also handle the Fortran 90 comment syntax where comments start
with ‘!’ and can follow other text. Because only some Fortran 77 compilers accept this
syntax, Fortran mode will not insert such comments unless you have said in advance to
do so. To do this, set the variable fortran-comment-line-start to ‘"!"’. If you use an
unusual value, you may need to change fortran-comment-line-start-skip.
M-;         Align comment or insert new comment (comment-dwim).
C-x ;       Applies to nonstandard ‘!’ comments only (comment-set-column).
C-c ;       Turn all lines of the region into comments, or (with argument) turn them back
            into real code (fortran-comment-region).
   M-; in Fortran mode runs the standard comment-dwim. This recognizes any kind of
existing comment and aligns its text appropriately; if there is no existing comment, a
comment is inserted and aligned. Inserting and aligning comments are not the same in
Fortran mode as in other modes.
    When a new comment must be inserted, if the current line is blank, a full-line comment
is inserted. On a non-blank line, a nonstandard ‘!’ comment is inserted if you have said
you want to use them. Otherwise, a full-line comment is inserted on a new line before the
current line.
   Nonstandard ‘!’ comments are aligned like comments in other languages, but full-line
comments are different. In a standard full-line comment, the comment delimiter itself must
always appear in column zero. What can be aligned is the text within the comment. You can
choose from three styles of alignment by setting the variable fortran-comment-indent-
style to one of these values:
fixed       Align the text at a fixed column, which is the sum of fortran-comment-line-
            extra-indent and the minimum statement indentation. This is the default.
            The minimum indentation is fortran-minimum-statement-indent-tab for
            tab format continuation line style and fortran-minimum-statement-indent-
            fixed for fixed form style.
relative    Align the text as if it were a line of code, but with an additional
            fortran-comment-line-extra-indent columns of indentation.
nil         Don’t move text in full-line comments automatically.
   In addition, you can specify the character to be used to indent within full-line comments
by setting the variable fortran-comment-indent-char to the single-character string you
want to use.
    Compiler directive lines, or preprocessor lines, have much the same appearance as
comment lines. It is important, though, that such lines never be indented at all, no matter
what the value of fortran-comment-indent-style. The variable fortran-directive-re
is a regular expression that specifies which lines are directives. Matching lines are never
indented, and receive distinctive font-locking.
   The normal Emacs comment command C-x ; (comment-set-column) has not been
redefined. If you use ‘!’ comments, this command can be used with them. Otherwise, it is
useless in Fortran mode.
Fortran Mode                                                                                     36



    The command C-c ; (fortran-comment-region) turns all the lines of the region into
comments by inserting the string ‘c$$$’ at the front of each one. With a numeric argument,
it turns the region back into live code by deleting ‘c$$$’ from the front of each line in it. The
string used for these comments can be controlled by setting the variable fortran-comment-
region. Note that here we have an example of a command and a variable with the same
name; these two uses of the name never conflict because in Lisp and in Emacs it is always
clear from the context which one is meant.

Auto Fill in Fortran Mode
Fortran mode has specialized support for Auto Fill mode, which is a minor mode that
automatically splits statements as you insert them when they become too wide. Splitting
a statement involves making continuation lines using fortran-continuation-string (see
[ForIndent Cont], page 32). This splitting happens when you type SPC, RET, or TAB, and
also in the Fortran indentation commands. You activate Auto Fill in Fortran mode in the
normal way. See Section “Auto Fill” in the Emacs Manual.
   Auto Fill breaks lines at spaces or delimiters when the lines get longer than the desired
width (the value of fill-column). The delimiters (besides whitespace) that Auto Fill can
break at are ‘+’, ‘-’, ‘/’, ‘*’, ‘=’, ‘<’, ‘>’, and ‘,’. The line break comes after the delimiter if
the variable fortran-break-before-delimiters is nil. Otherwise (and by default), the
break comes before the delimiter.
   To enable Auto Fill in all Fortran buffers, add auto-fill-mode to fortran-mode-hook.
See Section “Hooks” in the Emacs Manual.

Checking Columns in Fortran
In standard Fortran 77, anything beyond column 72 is ignored. Most compilers provide
an option to change this (for example, ‘-ffixed-line-length-N’ in gfortran). Customize
the variable fortran-line-length to change the line length in Fortran mode. Anything
beyond this point is font-locked as a comment. (Unless it is inside a string: strings that
extend beyond fortran-line-length will confuse font-lock.)
C-c C-r      Display a column ruler momentarily above the current line (fortran-column-
             ruler).
C-c C-w      Split the current window horizontally temporarily so that it is fortran-line-
             length columns wide (fortran-window-create-momentarily). This may help
             you avoid making lines longer than the limit imposed by your Fortran compiler.
C-u C-c C-w
           Split the current window horizontally so that it is fortran-line-length
           columns wide (fortran-window-create). You can then continue editing.
M-x fortran-strip-sequence-nos
          Delete all text in column fortran-line-length and beyond.
    The command C-c C-r (fortran-column-ruler) shows a column ruler momentarily
above the current line. The comment ruler is two lines of text that show you the locations
of columns with special significance in Fortran programs. Square brackets show the limits
Fortran Mode                                                                                 37



of the columns for line numbers, and curly brackets show the limits of the columns for the
statement body. Column numbers appear above them.
    Note that the column numbers count from zero, as always in GNU Emacs (but customiz-
ing column-number-indicator-zero-based can change column display to match that of
Fortran; see Section “Optional Mode Line” in the Emacs Manual.) As a result, the numbers
may be one less than those you are familiar with; but the positions they indicate in the line
are standard for Fortran.
    The text used to display the column ruler depends on the value of the variable
indent-tabs-mode.        If indent-tabs-mode is nil, then the value of the variable
fortran-column-ruler-fixed is used as the column ruler. Otherwise, the value of the
variable fortran-column-ruler-tab is displayed. By changing these variables, you can
change the column ruler display.
    C-c C-w (fortran-window-create-momentarily) temporarily splits the current window
horizontally, making a window fortran-line-length columns wide, so you can see any
lines that are too long. Type a space to restore the normal width.
    You can also split the window horizontally and continue editing with the split in place.
To do this, use C-u C-c C-w (M-x fortran-window-create). By editing in this window you
can immediately see when you make a line too wide to be correct Fortran.
    The command M-x fortran-strip-sequence-nos deletes all text in column
fortran-line-length and beyond, on all lines in the current buffer. This is the easiest
way to get rid of old sequence numbers.

Fortran Keyword Abbrevs
 Fortran mode provides many built-in abbrevs for common keywords and declarations. These
 are the same sort of abbrev that you can define yourself. To use them, you must turn on
 Abbrev mode. See Section “Abbrevs” in the Emacs Manual.
    The built-in abbrevs are unusual in one way: they all start with a semicolon. For
 example, one built-in Fortran abbrev is ‘;c’ for ‘continue’. If you insert ‘;c’ and then insert
 a punctuation character such as a space or a newline, the ‘;c’ expands automatically to
‘continue’, provided Abbrev mode is enabled.
    Type ‘;?’ or ‘;C-h’ to display a list of all the built-in Fortran abbrevs and what they
 stand for.
                                                                                           38



Emacs and MS-DOS
This section briefly describes the peculiarities of using Emacs on MS-DOS. Information
about Emacs and Microsoft’s current operating system Windows is in the main Emacs
manual (see Section “Microsoft Windows” in the Emacs Manual).
    If you build Emacs for MS-DOS, the binary will also run on Windows 3.X, Windows NT,
Windows 9X/ME, or Windows 2000/XP as a DOS application; all of this chapter applies
for all of those systems, if you use an Emacs that was built for MS-DOS.
   See Section “Text and Binary” in the Emacs Manual, for information about Emacs’s
special handling of text files under MS-DOS (and Windows).

Keyboard Usage on MS-DOS
The key that is called DEL in Emacs (because that’s how it is designated on most workstations)
is known as BS (backspace) on a PC. That is why the PC-specific terminal initialization
remaps the BS key to act as DEL; the Delete key is remapped to act as C-d for the same
reasons.
   Emacs built for MS-DOS recognizes C-Break as a quit character, just like C-g. This is
because Emacs cannot detect that you have typed C-g until it is ready for more input. As a
consequence, you cannot use C-g to stop a running command (see Section “Quitting” in
the Emacs Manual). By contrast, C-Break is detected as soon as you type it (as C-g is on
other systems), so it can be used to stop a running command and for emergency escape (see
Section “Emergency Escape” in the Emacs Manual).
    The PC keyboard maps use the left Alt key as the Meta key. You have two choices for
emulating the SUPER and Hyper keys: choose either the right Ctrl key or the right Alt key
by setting the variables dos-hyper-key and dos-super-key to 1 or 2 respectively. If neither
dos-super-key nor dos-hyper-key is 1, then by default the right Alt key is also mapped to
the Meta key. However, if the MS-DOS international keyboard support program KEYB.COM is
installed, Emacs will not map the right Alt to Meta, since it is used for accessing characters
like ~ and @ on non-US keyboard layouts; in this case, you may only use the left Alt as Meta
key.
   The variable dos-keypad-mode is a flag variable that controls what key codes are returned
by keys in the numeric keypad. You can also define the keypad ENTER key to act like C-j,
by putting the following line into your _emacs file:
      ;; Make the ENTER key from the numeric keypad act as C-j.
      (keymap-set function-key-map "<kp-enter>" "C-j")


Mouse Usage on MS-DOS
Emacs on MS-DOS supports a mouse (on the default terminal only). The mouse commands
work as documented, including those that use menus and the menu bar (see Section “Menu
Bar” in the Emacs Manual). Scroll bars don’t work in MS-DOS Emacs. PC mice usually
have only two buttons; these act as mouse-1 and mouse-2, but if you press both of them
together, that has the effect of mouse-3. If the mouse does have 3 buttons, Emacs detects
that at startup, and all the 3 buttons function normally, as on X.
Emacs and MS-DOS                                                                          39



   Help strings for menu-bar and pop-up menus are displayed in the echo area when the
mouse pointer moves across the menu items. Highlighting of mouse-sensitive text (see
Section “Mouse References” in the Emacs Manual) is also supported.
   Some versions of mouse drivers don’t report the number of mouse buttons correctly. For
example, mice with a wheel report that they have 3 buttons, but only 2 of them are passed
to Emacs; the clicks on the wheel, which serves as the middle button, are not passed. In
these cases, you can use the M-x msdos-set-mouse-buttons command to tell Emacs how
many mouse buttons to expect. You could make such a setting permanent by adding this
fragment to your _emacs init file:
      ;; Treat the mouse like a 2-button mouse.
      (msdos-set-mouse-buttons 2)
    Emacs built for MS-DOS supports clipboard operations when it runs on Windows.
Commands that put text on the kill ring, or yank text from the ring, check the Windows
clipboard first, just as Emacs does on the X Window System (see Section “Mouse Commands”
in the Emacs Manual). Only the primary selection and the cut buffer are supported by
MS-DOS Emacs on Windows; the secondary selection always appears as empty.
    Due to the way clipboard access is implemented by Windows, the length of text you can
put into the clipboard is limited by the amount of free DOS memory that is available to
Emacs. Usually, up to 620KB of text can be put into the clipboard, but this limit depends on
the system configuration and is lower if you run Emacs as a subprocess of another program.
If the killed text does not fit, Emacs outputs a message saying so, and does not put the text
into the clipboard.
   Null characters also cannot be put into the Windows clipboard. If the killed text includes
null characters, Emacs does not put such text into the clipboard, and displays in the echo
area a message to that effect.
   The variable dos-display-scancodes, when non-nil, directs Emacs to display the ASCII
value and the keyboard scan code of each keystroke; this feature serves as a complement to
the view-lossage command, for debugging.

Display on MS-DOS
Display on MS-DOS cannot use font variants, like bold or italic, but it does support multiple
faces, each of which can specify a foreground and a background color. Therefore, you can
get the full functionality of Emacs packages that use fonts (such as font-lock, Enriched
Text mode, and others) by defining the relevant faces to use different colors. Use the
list-colors-display command (see Section “Colors” in the Emacs Manual) and the
list-faces-display command (see Section “Faces” in the Emacs Manual) to see what
colors and faces are available and what they look like.
   See [MS-DOS and MULE], page 42, later in this chapter, for information on how Emacs
displays glyphs and characters that aren’t supported by the native font built into the DOS
display.
   When Emacs starts, it changes the cursor shape to a solid box. This is for compatibility
with other systems, where the box cursor is the default in Emacs. This default shape can be
changed to a bar by specifying the cursor-type parameter in the variable default-frame-
alist (see Section “Creating Frames” in the Emacs Manual). The MS-DOS terminal doesn’t
Emacs and MS-DOS                                                                              40



support a vertical-bar cursor, so the bar cursor is horizontal, and the width parameter, if
specified by the frame parameters, actually determines its height. For this reason, the bar
and hbar cursor types produce the same effect on MS-DOS. As an extension, the bar cursor
specification can include the starting scan line of the cursor as well as its width, like this:
       '(cursor-type bar width . start)
In addition, if the width parameter is negative, the cursor bar begins at the top of the
character cell.
   The MS-DOS terminal can only display a single frame at a time. The Emacs frame
facilities work on MS-DOS much as they do on text terminals (see Section “Frames” in the
Emacs Manual). When you run Emacs from a DOS window on MS-Windows, you can make
the visible frame smaller than the full screen, but Emacs still cannot display more than a
single frame at a time.
   The dos-mode4350 command switches the display to 43 or 50 lines, depending on your
hardware; the dos-mode25 command switches to the default 80x25 screen size.
   By default, Emacs only knows how to set screen sizes of 80 columns by 25, 28, 35, 40,
43 or 50 rows. However, if your video adapter has special video modes that will switch the
display to other sizes, you can have Emacs support those too. When you ask Emacs to
switch the frame to n rows by m columns dimensions, it checks if there is a variable called
screen-dimensions-nxm, and if so, uses its value (which must be an integer) as the video
mode to switch to. (Emacs switches to that video mode by calling the BIOS Set Video
Mode function with the value of screen-dimensions-nxm in the AL register.) For example,
suppose your adapter will switch to 66x80 dimensions when put into video mode 85. Then
you can make Emacs support this screen size by putting the following into your _emacs file:
      (setq screen-dimensions-66x80 85)
   Since Emacs on MS-DOS can only set the frame size to specific supported dimensions, it
cannot honor every possible frame resizing request. When an unsupported size is requested,
Emacs chooses the next larger supported size beyond the specified size. For example, if you
ask for 36x80 frame, you will get 40x80 instead.
    The variables screen-dimensions-nxm are used only when they exactly match the
specified size; the search for the next larger supported size ignores them. In the above example,
even if your VGA supports 38x80 dimensions and you define a variable screen-dimensions-
38x80 with a suitable value, you will still get 40x80 screen when you ask for a 36x80 frame.
If you want to get the 38x80 size in this case, you can do it by setting the variable named
screen-dimensions-36x80 with the same video mode value as screen-dimensions-38x80.
   Changing frame dimensions on MS-DOS has the effect of changing all the other frames
to the new dimensions.

File Names on MS-DOS
On MS-DOS, file names are case-insensitive and limited to eight characters, plus optionally
a period and three more characters. Emacs knows enough about these limitations to handle
file names that were meant for other operating systems. For instance, leading dots ‘.’ in
file names are invalid in MS-DOS, so Emacs transparently converts them to underscores ‘_’;
thus your default init file (see Section “Init File” in the Emacs Manual) is called _emacs on
MS-DOS. Excess characters before or after the period are generally ignored by MS-DOS
Emacs and MS-DOS                                                                            41



itself; thus, if you visit the file LongFileName.EvenLongerExtension, you will silently get
longfile.eve, but Emacs will still display the long file name on the mode line. Other than
that, it’s up to you to specify file names which are valid under MS-DOS; the transparent
conversion as described above only works on file names built into Emacs.
    The above restrictions on the file names on MS-DOS make it almost impossible to
construct the name of a backup file (see Section “Backup Names” in the Emacs Manual)
without losing some of the original file name characters. For example, the name of a backup
file for docs.txt is docs.tx~ even if single backup is used.
   If you run Emacs as a DOS application under Windows 9X, Windows ME, or Windows
2000/XP, you can turn on support for long file names. If you do that, Emacs doesn’t
truncate file names or convert them to lower case; instead, it uses the file names that you
specify, verbatim. To enable long file name support, set the environment variable LFN to ‘y’
before starting Emacs. Unfortunately, Windows NT doesn’t allow DOS programs to access
long file names, so Emacs built for MS-DOS will only see their short 8+3 aliases.
   MS-DOS has no notion of home directory, so Emacs on MS-DOS pretends that the
directory where it is installed is the value of the HOME environment variable. That is, if your
Emacs binary, emacs.exe, is in the directory c:/utils/emacs/bin, then Emacs acts as if
HOME were set to ‘c:/utils/emacs’. In particular, that is where Emacs looks for the init file
_emacs. With this in mind, you can use ‘~’ in file names as an alias for the home directory,
as you would on GNU or Unix. You can also set HOME variable in the environment before
starting Emacs; its value will then override the above default behavior.
    Emacs on MS-DOS handles the name /dev specially, because of a feature in the emulator
libraries of DJGPP that pretends I/O devices have names in that directory. We recommend
that you avoid using an actual directory named /dev on any disk.


Printing and MS-DOS
Printing commands, such as lpr-buffer (see Section “Printing” in the Emacs Manual) and
ps-print-buffer (see Section “PostScript” in the Emacs Manual) can work on MS-DOS by
sending the output to one of the printer ports, if a POSIX-style lpr program is unavailable.
The same Emacs variables control printing on all systems, but in some cases they have
different default values on MS-DOS.
   See Section “Windows Printing” in the Emacs Manual, for details about setting up
printing to a networked printer.
   Some printers expect DOS codepage encoding of non-ASCII text, even though they are
connected to a Windows machine that uses a different encoding for the same locale. For
example, in the Latin-1 locale, DOS uses codepage 850 whereas Windows uses codepage 1252.
See [MS-DOS and MULE], page 42. When you print to such printers from Windows, you
can use the C-x RET c (universal-coding-system-argument) command before M-x lpr-
buffer; Emacs will then convert the text to the DOS codepage that you specify. For example,
C-x RET c cp850-dos RET M-x lpr-region RET will print the region while converting it to
the codepage 850 encoding.
   For backwards compatibility, the value of dos-printer (dos-ps-printer), if it has a
value, overrides the value of printer-name (ps-printer-name), on MS-DOS.
Emacs and MS-DOS                                                                                        42



International Support on MS-DOS
Emacs on MS-DOS supports the same international character sets as it does on GNU, Unix
and other platforms (see Section “International” in the Emacs Manual), including coding
systems for converting between the different character sets. However, due to incompatibilities
between MS-DOS/MS-Windows and other systems, there are several DOS-specific aspects
of this support that you should be aware of. This section describes these aspects.
    The description below is largely specific to the MS-DOS port of Emacs, especially where
it talks about practical implications for Emacs users.

M-x dos-codepage-setup
          Set up Emacs display and coding systems as appropriate for the current DOS
          codepage.

   MS-DOS is designed to support one character set of 256 characters at any given time,
but gives you a variety of character sets to choose from. The alternative character sets are
known as DOS codepages. Each codepage includes all 128 ASCII characters, but the other
128 characters (codes 128 through 255) vary from one codepage to another. Each DOS
codepage is identified by a 3-digit number, such as 850, 862, etc.
   In contrast to X, which lets you use several fonts at the same time, MS-DOS normally
doesn’t allow use of several codepages in a single session. MS-DOS was designed to load
a single codepage at system startup, and require you to reboot in order to change it1 .
Much the same limitation applies when you run DOS executables on other systems such as
MS-Windows.
   For multibyte operation on MS-DOS, Emacs needs to know which characters the chosen
DOS codepage can display. So it queries the system shortly after startup to get the chosen
codepage number, and stores the number in the variable dos-codepage. Some systems
return the default value 437 for the current codepage, even though the actual codepage
is different. (This typically happens when you use the codepage built into the display
hardware.) You can specify a different codepage for Emacs to use by setting the variable
dos-codepage in your init file.
   Multibyte Emacs supports only certain DOS codepages: those which can display Far-
Eastern scripts, like the Japanese codepage 932, and those that encode a single ISO 8859
character set.
   The Far-Eastern codepages can directly display one of the MULE character sets for these
countries, so Emacs simply sets up to use the appropriate terminal coding system that is
supported by the codepage. The special features described in the rest of this section mostly
pertain to codepages that encode ISO 8859 character sets.
   For the codepages that correspond to one of the ISO character sets, Emacs knows the
character set based on the codepage number. Emacs automatically creates a coding system
to support reading and writing files that use the current codepage, and uses this coding

 1
     Normally, one particular codepage is burnt into the display memory, while other codepages can be
     installed by modifying system configuration files, such as CONFIG.SYS, and rebooting. While there is
     third-party software that allows changing the codepage without rebooting, we describe here how a stock
     MS-DOS system behaves.
Emacs and MS-DOS                                                                                       43



 system by default. The name of this coding system is cpnnn, where nnn is the codepage
 number.2
     All the cpnnn coding systems use the letter ‘D’ (for “DOS”) as their mode-line mnemonic.
 Since both the terminal coding system and the default coding system for file I/O are set
 to the proper cpnnn coding system at startup, it is normal for the mode line on MS-DOS
 to begin with ‘-DD\-’. See Section “Mode Line” in the Emacs Manual. Far-Eastern DOS
 terminals do not use the cpnnn coding systems, and thus their initial mode line looks like
 the Emacs default.
     Since the codepage number also indicates which script you are using, Emacs automatically
 runs set-language-environment to select the language environment for that script (see
 Section “Language Environments” in the Emacs Manual).
     If a buffer contains a character belonging to some other ISO 8859 character set, not the
 one that the chosen DOS codepage supports, Emacs displays it using a sequence of ASCII
 characters. For example, if the current codepage doesn’t have a glyph for the letter ‘ò’ (small
‘o’ with a grave accent), it is displayed as ‘{`o}’, where the braces serve as a visual indication
 that this is a single character. (This may look awkward for some non-Latin characters, such
 as those from Greek or Hebrew alphabets, but it is still readable by a person who knows the
 language.) Even though the character may occupy several columns on the screen, it is really
 still just a single character, and all Emacs commands treat it as one.
     MS-Windows provides its own codepages, which are different from the DOS codepages
 for the same locale. For example, DOS codepage 850 supports the same character set as
 Windows codepage 1252; DOS codepage 855 supports the same character set as Windows
 codepage 1251, etc. The MS-Windows version of Emacs uses the current codepage for display
 when invoked with the ‘-nw’ option.

Subprocesses on MS-DOS
Because MS-DOS is a single-process “operating system”, asynchronous subprocesses are not
available. In particular, Shell mode and its variants do not work. Most Emacs features that
use asynchronous subprocesses also don’t work on MS-DOS, including Shell mode and GUD.
When in doubt, try and see; commands that don’t work output an error message saying
that asynchronous processes aren’t supported.
   Compilation under Emacs with M-x compile, searching files with M-x grep and dis-
playing differences between files with M-x diff do work, by running the inferior processes
synchronously. This means you cannot do any more editing until the inferior process finishes.
   Spell checking also works, by means of special support for synchronous invocation of the
ispell program. This is slower than the asynchronous invocation on other platforms.
   Instead of the Shell mode, which doesn’t work on MS-DOS, you can use the M-x eshell
command. This invokes the Eshell package that implements a POSIX-like shell entirely in
Emacs Lisp.
   By contrast, Emacs compiled as a native Windows application does support asynchronous
subprocesses. See Section “Windows Processes” in the Emacs Manual.
 2
     The standard Emacs coding systems for ISO 8859 are not quite right for the purpose, because typically
     the DOS codepage does not match the standard ISO character codes. For example, the letter ‘ç’ (‘c’
     with cedilla) has code 231 in the standard Latin-1 character set, but the corresponding DOS codepage
     850 uses code 135 for this glyph.
Emacs and MS-DOS                                                                        44



    Printing commands, such as lpr-buffer (see Section “Printing” in the Emacs Manual)
 and ps-print-buffer (see Section “PostScript” in the Emacs Manual), work in MS-DOS
 by sending the output to one of the printer ports. See Section “MS-DOS Printing” in the
 Emacs Manual.
    When you run a subprocess synchronously on MS-DOS, make sure the program terminates
 and does not try to read keyboard input. If the program does not terminate on its own, you
 will be unable to terminate it, because MS-DOS provides no general way to terminate a
 process. Pressing C-c or C-Break might sometimes help in these cases.
    Accessing files on other machines is not supported on MS-DOS. Other network-oriented
 commands such as sending mail, Web browsing, remote login, etc., don’t work either, unless
 network access is built into MS-DOS with some network redirector.
    Dired on MS-DOS uses the ls-lisp package (see Section “ls in Lisp” in the Emacs
 Manual). Therefore, Dired on MS-DOS supports only some of the possible options you can
 mention in the dired-listing-switches variable. The options that work are ‘-A’, ‘-a’,
‘-c’, ‘-i’, ‘-r’, ‘-S’, ‘-s’, ‘-t’, and ‘-u’.
                                                                                         45



Appendix A GNU Free Documentation License
                          Version 1.3, 3 November 2008
    Copyright c 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
    https://fsf.org/

     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.
0. PREAMBLE
   The purpose of this License is to make a manual, textbook, or other functional and
   useful document free in the sense of freedom: to assure everyone the effective freedom
   to copy and redistribute it, with or without modifying it, either commercially or
   noncommercially. Secondarily, this License preserves for the author and publisher a way
   to get credit for their work, while not being considered responsible for modifications
   made by others.
   This License is a kind of “copyleft”, which means that derivative works of the document
   must themselves be free in the same sense. It complements the GNU General Public
   License, which is a copyleft license designed for free software.
   We have designed this License in order to use it for manuals for free software, because
   free software needs free documentation: a free program should come with manuals
   providing the same freedoms that the software does. But this License is not limited to
   software manuals; it can be used for any textual work, regardless of subject matter or
   whether it is published as a printed book. We recommend this License principally for
   works whose purpose is instruction or reference.
1. APPLICABILITY AND DEFINITIONS
   This License applies to any manual or other work, in any medium, that contains a notice
   placed by the copyright holder saying it can be distributed under the terms of this
   License. Such a notice grants a world-wide, royalty-free license, unlimited in duration,
   to use that work under the conditions stated herein. The “Document”, below, refers
   to any such manual or work. Any member of the public is a licensee, and is addressed
   as “you”. You accept the license if you copy, modify or distribute the work in a way
   requiring permission under copyright law.
   A “Modified Version” of the Document means any work containing the Document or
   a portion of it, either copied verbatim, or with modifications and/or translated into
   another language.
   A “Secondary Section” is a named appendix or a front-matter section of the Document
   that deals exclusively with the relationship of the publishers or authors of the Document
   to the Document’s overall subject (or to related matters) and contains nothing that
   could fall directly within that overall subject. (Thus, if the Document is in part a
   textbook of mathematics, a Secondary Section may not explain any mathematics.) The
   relationship could be a matter of historical connection with the subject or with related
   matters, or of legal, commercial, philosophical, ethical or political position regarding
   them.
   The “Invariant Sections” are certain Secondary Sections whose titles are designated, as
   being those of Invariant Sections, in the notice that says that the Document is released
Appendix A: GNU Free Documentation License                                                  46



   under this License. If a section does not fit the above definition of Secondary then it is
   not allowed to be designated as Invariant. The Document may contain zero Invariant
   Sections. If the Document does not identify any Invariant Sections then there are none.
   The “Cover Texts” are certain short passages of text that are listed, as Front-Cover
   Texts or Back-Cover Texts, in the notice that says that the Document is released under
   this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may
   be at most 25 words.
   A “Transparent” copy of the Document means a machine-readable copy, represented in a
   format whose specification is available to the general public, that is suitable for revising
   the document straightforwardly with generic text editors or (for images composed of
   pixels) generic paint programs or (for drawings) some widely available drawing editor,
   and that is suitable for input to text formatters or for automatic translation to a
   variety of formats suitable for input to text formatters. A copy made in an otherwise
   Transparent file format whose markup, or absence of markup, has been arranged to
   thwart or discourage subsequent modification by readers is not Transparent. An image
   format is not Transparent if used for any substantial amount of text. A copy that is
   not “Transparent” is called “Opaque”.
   Examples of suitable formats for Transparent copies include plain ASCII without
   markup, Texinfo input format, LaTEX input format, SGML or XML using a publicly
   available DTD, and standard-conforming simple HTML, PostScript or PDF designed
   for human modification. Examples of transparent image formats include PNG, XCF
   and JPG. Opaque formats include proprietary formats that can be read and edited only
   by proprietary word processors, SGML or XML for which the DTD and/or processing
   tools are not generally available, and the machine-generated HTML, PostScript or PDF
   produced by some word processors for output purposes only.
   The “Title Page” means, for a printed book, the title page itself, plus such following
   pages as are needed to hold, legibly, the material this License requires to appear in the
   title page. For works in formats which do not have any title page as such, “Title Page”
   means the text near the most prominent appearance of the work’s title, preceding the
   beginning of the body of the text.
   The “publisher” means any person or entity that distributes copies of the Document to
   the public.
   A section “Entitled XYZ” means a named subunit of the Document whose title either
   is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in
   another language. (Here XYZ stands for a specific section name mentioned below, such
   as “Acknowledgements”, “Dedications”, “Endorsements”, or “History”.) To “Preserve
   the Title” of such a section when you modify the Document means that it remains a
   section “Entitled XYZ” according to this definition.
   The Document may include Warranty Disclaimers next to the notice which states that
   this License applies to the Document. These Warranty Disclaimers are considered to be
   included by reference in this License, but only as regards disclaiming warranties: any
   other implication that these Warranty Disclaimers may have is void and has no effect
   on the meaning of this License.
 2. VERBATIM COPYING
Appendix A: GNU Free Documentation License                                                47



    You may copy and distribute the Document in any medium, either commercially or
    noncommercially, provided that this License, the copyright notices, and the license
    notice saying this License applies to the Document are reproduced in all copies, and
    that you add no other conditions whatsoever to those of this License. You may not use
    technical measures to obstruct or control the reading or further copying of the copies
    you make or distribute. However, you may accept compensation in exchange for copies.
    If you distribute a large enough number of copies you must also follow the conditions in
    section 3.
    You may also lend copies, under the same conditions stated above, and you may publicly
    display copies.
 3. COPYING IN QUANTITY
    If you publish printed copies (or copies in media that commonly have printed covers) of
    the Document, numbering more than 100, and the Document’s license notice requires
    Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all
    these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
    the back cover. Both covers must also clearly and legibly identify you as the publisher
    of these copies. The front cover must present the full title with all words of the title
    equally prominent and visible. You may add other material on the covers in addition.
    Copying with changes limited to the covers, as long as they preserve the title of the
    Document and satisfy these conditions, can be treated as verbatim copying in other
    respects.
    If the required texts for either cover are too voluminous to fit legibly, you should put
    the first ones listed (as many as fit reasonably) on the actual cover, and continue the
    rest onto adjacent pages.
    If you publish or distribute Opaque copies of the Document numbering more than 100,
    you must either include a machine-readable Transparent copy along with each Opaque
    copy, or state in or with each Opaque copy a computer-network location from which
    the general network-using public has access to download using public-standard network
    protocols a complete Transparent copy of the Document, free of added material. If
    you use the latter option, you must take reasonably prudent steps, when you begin
    distribution of Opaque copies in quantity, to ensure that this Transparent copy will
    remain thus accessible at the stated location until at least one year after the last time
    you distribute an Opaque copy (directly or through your agents or retailers) of that
    edition to the public.
    It is requested, but not required, that you contact the authors of the Document well
    before redistributing any large number of copies, to give them a chance to provide you
    with an updated version of the Document.
 4. MODIFICATIONS
    You may copy and distribute a Modified Version of the Document under the conditions
    of sections 2 and 3 above, provided that you release the Modified Version under precisely
    this License, with the Modified Version filling the role of the Document, thus licensing
    distribution and modification of the Modified Version to whoever possesses a copy of it.
    In addition, you must do these things in the Modified Version:
     A. Use in the Title Page (and on the covers, if any) a title distinct from that of the
          Document, and from those of previous versions (which should, if there were any,
Appendix A: GNU Free Documentation License                                                  48



        be listed in the History section of the Document). You may use the same title as a
        previous version if the original publisher of that version gives permission.
    B. List on the Title Page, as authors, one or more persons or entities responsible for
       authorship of the modifications in the Modified Version, together with at least five
       of the principal authors of the Document (all of its principal authors, if it has fewer
       than five), unless they release you from this requirement.
    C. State on the Title page the name of the publisher of the Modified Version, as the
       publisher.
    D. Preserve all the copyright notices of the Document.
    E. Add an appropriate copyright notice for your modifications adjacent to the other
       copyright notices.
    F. Include, immediately after the copyright notices, a license notice giving the public
       permission to use the Modified Version under the terms of this License, in the form
       shown in the Addendum below.
    G. Preserve in that license notice the full lists of Invariant Sections and required Cover
       Texts given in the Document’s license notice.
    H. Include an unaltered copy of this License.
     I. Preserve the section Entitled “History”, Preserve its Title, and add to it an item
        stating at least the title, year, new authors, and publisher of the Modified Version as
        given on the Title Page. If there is no section Entitled “History” in the Document,
        create one stating the title, year, authors, and publisher of the Document as given
        on its Title Page, then add an item describing the Modified Version as stated in
        the previous sentence.
     J. Preserve the network location, if any, given in the Document for public access to
         a Transparent copy of the Document, and likewise the network locations given in
         the Document for previous versions it was based on. These may be placed in the
        “History” section. You may omit a network location for a work that was published
         at least four years before the Document itself, or if the original publisher of the
        version it refers to gives permission.
    K. For any section Entitled “Acknowledgements” or “Dedications”, Preserve the Title
       of the section, and preserve in the section all the substance and tone of each of the
       contributor acknowledgements and/or dedications given therein.
    L. Preserve all the Invariant Sections of the Document, unaltered in their text and
       in their titles. Section numbers or the equivalent are not considered part of the
       section titles.
    M. Delete any section Entitled “Endorsements”. Such a section may not be included
       in the Modified Version.
    N. Do not retitle any existing section to be Entitled “Endorsements” or to conflict in
       title with any Invariant Section.
    O. Preserve any Warranty Disclaimers.
   If the Modified Version includes new front-matter sections or appendices that qualify as
   Secondary Sections and contain no material copied from the Document, you may at
   your option designate some or all of these sections as invariant. To do this, add their
Appendix A: GNU Free Documentation License                                                   49



   titles to the list of Invariant Sections in the Modified Version’s license notice. These
   titles must be distinct from any other section titles.
   You may add a section Entitled “Endorsements”, provided it contains nothing but
   endorsements of your Modified Version by various parties—for example, statements of
   peer review or that the text has been approved by an organization as the authoritative
   definition of a standard.
   You may add a passage of up to five words as a Front-Cover Text, and a passage of up
   to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified
   Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be
   added by (or through arrangements made by) any one entity. If the Document already
   includes a cover text for the same cover, previously added by you or by arrangement
   made by the same entity you are acting on behalf of, you may not add another; but
   you may replace the old one, on explicit permission from the previous publisher that
   added the old one.
   The author(s) and publisher(s) of the Document do not by this License give permission
   to use their names for publicity for or to assert or imply endorsement of any Modified
   Version.
 5. COMBINING DOCUMENTS
   You may combine the Document with other documents released under this License,
   under the terms defined in section 4 above for modified versions, provided that you
   include in the combination all of the Invariant Sections of all of the original documents,
   unmodified, and list them all as Invariant Sections of your combined work in its license
   notice, and that you preserve all their Warranty Disclaimers.
   The combined work need only contain one copy of this License, and multiple identical
   Invariant Sections may be replaced with a single copy. If there are multiple Invariant
   Sections with the same name but different contents, make the title of each such section
   unique by adding at the end of it, in parentheses, the name of the original author or
   publisher of that section if known, or else a unique number. Make the same adjustment
   to the section titles in the list of Invariant Sections in the license notice of the combined
   work.
   In the combination, you must combine any sections Entitled “History” in the various
   original documents, forming one section Entitled “History”; likewise combine any
   sections Entitled “Acknowledgements”, and any sections Entitled “Dedications”. You
   must delete all sections Entitled “Endorsements.”
 6. COLLECTIONS OF DOCUMENTS
   You may make a collection consisting of the Document and other documents released
   under this License, and replace the individual copies of this License in the various
   documents with a single copy that is included in the collection, provided that you follow
   the rules of this License for verbatim copying of each of the documents in all other
   respects.
   You may extract a single document from such a collection, and distribute it individually
   under this License, provided you insert a copy of this License into the extracted
   document, and follow this License in all other respects regarding verbatim copying of
   that document.
Appendix A: GNU Free Documentation License                                                    50



 7. AGGREGATION WITH INDEPENDENT WORKS
   A compilation of the Document or its derivatives with other separate and independent
    documents or works, in or on a volume of a storage or distribution medium, is called an
   “aggregate” if the copyright resulting from the compilation is not used to limit the legal
    rights of the compilation’s users beyond what the individual works permit. When the
    Document is included in an aggregate, this License does not apply to the other works
    in the aggregate which are not themselves derivative works of the Document.
   If the Cover Text requirement of section 3 is applicable to these copies of the Document,
   then if the Document is less than one half of the entire aggregate, the Document’s Cover
   Texts may be placed on covers that bracket the Document within the aggregate, or the
   electronic equivalent of covers if the Document is in electronic form. Otherwise they
   must appear on printed covers that bracket the whole aggregate.
 8. TRANSLATION
   Translation is considered a kind of modification, so you may distribute translations
   of the Document under the terms of section 4. Replacing Invariant Sections with
   translations requires special permission from their copyright holders, but you may
   include translations of some or all Invariant Sections in addition to the original versions
   of these Invariant Sections. You may include a translation of this License, and all the
   license notices in the Document, and any Warranty Disclaimers, provided that you also
   include the original English version of this License and the original versions of those
   notices and disclaimers. In case of a disagreement between the translation and the
   original version of this License or a notice or disclaimer, the original version will prevail.
   If a section in the Document is Entitled “Acknowledgements”, “Dedications”, or “His-
   tory”, the requirement (section 4) to Preserve its Title (section 1) will typically require
   changing the actual title.
 9. TERMINATION
   You may not copy, modify, sublicense, or distribute the Document except as expressly
   provided under this License. Any attempt otherwise to copy, modify, sublicense, or
   distribute it is void, and will automatically terminate your rights under this License.
   However, if you cease all violation of this License, then your license from a particular
   copyright holder is reinstated (a) provisionally, unless and until the copyright holder
   explicitly and finally terminates your license, and (b) permanently, if the copyright
   holder fails to notify you of the violation by some reasonable means prior to 60 days
   after the cessation.
   Moreover, your license from a particular copyright holder is reinstated permanently if
   the copyright holder notifies you of the violation by some reasonable means, this is the
   first time you have received notice of violation of this License (for any work) from that
   copyright holder, and you cure the violation prior to 30 days after your receipt of the
   notice.
   Termination of your rights under this section does not terminate the licenses of parties
   who have received copies or rights from you under this License. If your rights have been
   terminated and not permanently reinstated, receipt of a copy of some or all of the same
   material does not give you any rights to use it.
Appendix A: GNU Free Documentation License                                                     51



10. FUTURE REVISIONS OF THIS LICENSE
    The Free Software Foundation may publish new, revised versions of the GNU Free
     Documentation License from time to time. Such new versions will be similar in spirit
     to the present version, but may differ in detail to address new problems or concerns.
     See https://www.gnu.org/licenses/.
     Each version of the License is given a distinguishing version number. If the Document
     specifies that a particular numbered version of this License “or any later version” applies
     to it, you have the option of following the terms and conditions either of that specified
    version or of any later version that has been published (not as a draft) by the Free
     Software Foundation. If the Document does not specify a version number of this License,
     you may choose any version ever published (not as a draft) by the Free Software
     Foundation. If the Document specifies that a proxy can decide which future versions
     of this License can be used, that proxy’s public statement of acceptance of a version
     permanently authorizes you to choose that version for the Document.
11. RELICENSING
    “Massive Multiauthor Collaboration Site” (or “MMC Site”) means any World Wide
    Web server that publishes copyrightable works and also provides prominent facilities for
     anybody to edit those works. A public wiki that anybody can edit is an example of
     such a server. A “Massive Multiauthor Collaboration” (or “MMC”) contained in the
     site means any set of copyrightable works thus published on the MMC site.
    “CC-BY-SA” means the Creative Commons Attribution-Share Alike 3.0 license published
     by Creative Commons Corporation, a not-for-profit corporation with a principal place
     of business in San Francisco, California, as well as future copyleft versions of that license
     published by that same organization.
    “Incorporate” means to publish or republish a Document, in whole or in part, as part of
     another Document.
    An MMC is “eligible for relicensing” if it is licensed under this License, and if all works
     that were first published under this License somewhere other than this MMC, and
     subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or
     invariant sections, and (2) were thus incorporated prior to November 1, 2008.
    The operator of an MMC Site may republish an MMC contained in the site under
     CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is
     eligible for relicensing.
Appendix A: GNU Free Documentation License                                           52



ADDENDUM: How to use this License for your documents
To use this License in a document you have written, include a copy of the License in the
document and put the following copyright and license notices just after the title page:
        Copyright (C) year your name.
        Permission is granted to copy, distribute and/or modify this document
        under the terms of the GNU Free Documentation License, Version 1.3
        or any later version published by the Free Software Foundation;
        with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
        Texts. A copy of the license is included in the section entitled ``GNU
        Free Documentation License''.
   If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the
“with. . . Texts.” line with this:
         with the Invariant Sections being list their titles, with
         the Front-Cover Texts being list, and with the Back-Cover Texts
         being list.
   If you have Invariant Sections without Cover Texts, or some other combination of the
three, merge those two alternatives to suit the situation.
   If your document contains nontrivial examples of program code, we recommend releasing
these examples in parallel under your choice of free software license, such as the GNU
General Public License, to permit their use in free software.
                                                                                                                                                                          53



Index

A                                                                                    C-x v ! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
A and B buffers (Emerge) . . . . . . . . . . . . . . . . . . . . . . 20              C-x v a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
automatic version backups . . . . . . . . . . . . . . . . . . . . . 29               C-x v r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
                                                                                     C-x v s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
                                                                                     calendar layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
B                                                                                    calendar week numbers . . . . . . . . . . . . . . . . . . . . . . . . . . 8
                                                                                     calendar-bahai-all-holidays-flag . . . . . . . . . . . . 9
backup file names on MS-DOS . . . . . . . . . . . . . . . . . 41                     calendar-christian-all-holidays-flag . . . . . . . 9
BS (MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38   calendar-date-display-form. . . . . . . . . . . . . . . . . . 12
buffer-auto-revert-by-notification . . . . . . . . . 5                               calendar-day-header-array . . . . . . . . . . . . . . . . . . . . 8
                                                                                     calendar-hebrew-all-holidays-flag . . . . . . . . . . . 9
                                                                                     calendar-holiday-marker . . . . . . . . . . . . . . . . . . . . . . 8
C                                                                                    calendar-holidays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
C-Break (MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38          calendar-initial-window-hook . . . . . . . . . . . . . . . . 8
C-c ' (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3         calendar-intermonth-text . . . . . . . . . . . . . . . . . . . . . 8
C-c . (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3         calendar-islamic-all-holidays-flag . . . . . . . . . 9
C-c / (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3         calendar-mark-today . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
C-c ; (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . . . 35          calendar-mayan-goto-long-count-date . . . . . . . 11
C-c < (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3         calendar-mayan-next-calendar-round-date . . . 11
C-c > (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3         calendar-mayan-next-haab-date . . . . . . . . . . . . . . 11
C-c ^ (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3         calendar-mayan-next-tzolkin-date . . . . . . . . . . . 11
C-c ` (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3         calendar-mayan-previous-haab-date . . . . . . . . . 11
C-c \ (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3         calendar-mayan-previous-tzolkin-date . . . . . . 11
C-c C-a (F90 mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 31          calendar-month-header . . . . . . . . . . . . . . . . . . . . . . . . 8
C-c C-b (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 3           calendar-move-hook . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
C-c C-d (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . 32            calendar-star-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
C-c C-d (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 3           calendar-time-display-form. . . . . . . . . . . . . . . . . . 12
C-c C-e (F90 mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 31          calendar-today-invisible-hook . . . . . . . . . . . . . . . 8
C-c C-f (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 3           calendar-today-marker . . . . . . . . . . . . . . . . . . . . . . . . 8
C-c C-k (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 4           calendar-today-visible-hook . . . . . . . . . . . . . . . . . 8
C-c C-n (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . 31            candle lighting times . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
C-c C-p (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . 31            codepage, MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
C-c C-r (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . 36            compilation under MS-DOS . . . . . . . . . . . . . . . . . . . . 43
C-c C-w (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . 37            compile (MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
C-c C-w (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 4           cursor shape on MS-DOS . . . . . . . . . . . . . . . . . . . . . . 39
C-c C-x (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 4
C-c C-y (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 4
C-c DOWN (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . 3            D
C-c End (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 3           DEL (MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
C-c Home (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . 3            diary buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
C-c LEFT (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . 3            diary-anniversary, and sexp diary entries . . . . . 16
C-c next (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . 3            diary-astro-day-number . . . . . . . . . . . . . . . . . . . . . . 18
C-c PageDown (Picture mode) . . . . . . . . . . . . . . . . . . . 3                  diary-bahai-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C-c PageUp (Picture mode) . . . . . . . . . . . . . . . . . . . . . . 3              diary-bahai-entry-symbol . . . . . . . . . . . . . . . . . . . . 14
C-c prior (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . 3             diary-bahai-insert-entry . . . . . . . . . . . . . . . . . . . . 14
C-c RIGHT (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . 3             diary-bahai-insert-monthly-entry . . . . . . . . . . . 14
C-c TAB (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . 4           diary-bahai-insert-yearly-entry . . . . . . . . . . . . 14
C-c UP (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . 3          diary-bahai-list-entries . . . . . . . . . . . . . . . . . . . . 13
C-g (MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38    diary-bahai-mark-entries . . . . . . . . . . . . . . . . . . . . 13
C-j (MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38    diary-chinese-date . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C-M-j (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . . . 32          diary-chinese-entry-symbol. . . . . . . . . . . . . . . . . . 14
C-M-n (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . . . 31          diary-chinese-insert-anniversary-entry . . . . 14
C-M-p (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . . . 31          diary-chinese-insert-entry. . . . . . . . . . . . . . . . . . 14
C-M-q (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . . . 32          diary-chinese-insert-monthly-entry . . . . . . . . 14
C-u C-c C-w (Fortran mode) . . . . . . . . . . . . . . . . . . . . 37                diary-chinese-insert-yearly-entry . . . . . . . . . 14
Index                                                                                                                                                                       54



diary-chinese-list-entries. . . . . . . . . . . . . . . . . . 13                        dos-codepage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
diary-chinese-mark-entries. . . . . . . . . . . . . . . . . . 13                        dos-display-scancodes . . . . . . . . . . . . . . . . . . . . . . . 39
diary-comment-start. . . . . . . . . . . . . . . . . . . . . . . . . . 16               dos-hyper-key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
diary-coptic-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18            dos-keypad-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
diary-cyclic, and sexp diary entries. . . . . . . . . . . 16                            dos-mode25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
diary-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17   dos-mode4350 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
diary-date-forms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12           dos-printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
diary-day-of-year . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18            dos-ps-printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
diary-display-function . . . . . . . . . . . . . . . . . . . . . . 15                   dos-super-key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
diary-entry-marker . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8            DOS codepages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
diary-ethiopic-date. . . . . . . . . . . . . . . . . . . . . . . . . . 18
diary-fancy-display. . . . . . . . . . . . . . . . . . . . . . . . . . 15
diary-float, and sexp diary entries . . . . . . . . . . . . 17                          E
diary-french-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18            editing in Picture mode . . . . . . . . . . . . . . . . . . . . . . . . . 2
diary-hebrew-birthday . . . . . . . . . . . . . . . . . . . . . . . 19                  Emerge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
diary-hebrew-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18            emerge-auto-advance. . . . . . . . . . . . . . . . . . . . . . . . . . 21
diary-hebrew-entry-symbol . . . . . . . . . . . . . . . . . . . 14                      emerge-buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
diary-hebrew-insert-entry . . . . . . . . . . . . . . . . . . . 14                      emerge-buffers-with-ancestor . . . . . . . . . . . . . . . 20
diary-hebrew-insert-monthly-entry . . . . . . . . . 14                                  emerge-combine-versions-template . . . . . . . . . . . 24
diary-hebrew-insert-yearly-entry . . . . . . . . . . . 14                               emerge-files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
diary-hebrew-list-entries . . . . . . . . . . . . . . . . . . . 13                      emerge-files-with-ancestor. . . . . . . . . . . . . . . . . . 20
diary-hebrew-mark-entries . . . . . . . . . . . . . . . . . . . 13                      emerge-skip-prefers. . . . . . . . . . . . . . . . . . . . . . . . . . 21
diary-hebrew-omer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19            emerge-startup-hook. . . . . . . . . . . . . . . . . . . . . . . . . . 24
diary-hebrew-parasha . . . . . . . . . . . . . . . . . . . . . . . . 19
diary-hebrew-rosh-hodesh . . . . . . . . . . . . . . . . . . . . 19
diary-hebrew-sabbath-candles . . . . . . . . . . . . . . . 19                           F
diary-hebrew-yahrzeit . . . . . . . . . . . . . . . . . . . . . . . 19                  f90-beginning-of-block . . . . . . . . . . . . . . . . . . . . . . 31
diary-include-other-diary-files . . . . . . . . . . . . 16                              f90-end-of-block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
diary-include-string . . . . . . . . . . . . . . . . . . . . . . . . 16                 f90-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
diary-islamic-date . . . . . . . . . . . . . . . . . . . . . . . . . . . 18             f90-next-block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
diary-islamic-entry-symbol. . . . . . . . . . . . . . . . . . 14                        f90-next-statement . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
diary-islamic-insert-entry. . . . . . . . . . . . . . . . . . 14                        f90-previous-block . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
diary-islamic-insert-monthly-entry . . . . . . . . 14                                   f90-previous-statement . . . . . . . . . . . . . . . . . . . . . . 31
diary-islamic-insert-yearly-entry . . . . . . . . . 14                                  faces under MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
diary-islamic-list-entries. . . . . . . . . . . . . . . . . . 13                        file names under MS-DOS . . . . . . . . . . . . . . . . . . . . . . 40
diary-islamic-mark-entries. . . . . . . . . . . . . . . . . . 13                        file names under Windows 95/NT . . . . . . . . . . . . . . 41
diary-iso-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18         fonts, emulating under MS-DOS . . . . . . . . . . . . . . . . 39
diary-julian-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18            Fortran 77 and Fortran 90, 95, 2003, 2008 . . . . . . 31
diary-list-entries-hook . . . . . . . . . . . . . . . . . . . . . 16                    Fortran continuation lines . . . . . . . . . . . . . . . . . . . . . . 32
diary-list-include-blanks . . . . . . . . . . . . . . . . . . . 15                      Fortran fixed form and free form . . . . . . . . . . . . . . . 31
diary-lunar-phases . . . . . . . . . . . . . . . . . . . . . . . . . . . 18             Fortran mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
diary-mark-entries-hook . . . . . . . . . . . . . . . . . . . . . 16                    fortran-analyze-depth . . . . . . . . . . . . . . . . . . . . . . . 32
diary-mark-included-diary-files . . . . . . . . . . . . 16                              fortran-beginning-of-block. . . . . . . . . . . . . . . . . . 31
diary-mayan-date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18           fortran-break-before-delimiters . . . . . . . . . . . . 36
diary-nongregorian-listing-hook . . . . . . . . . . . . 13                              fortran-check-all-num... . . . . . . . . . . . . . . . . . . . . 34
diary-nongregorian-marking-hook . . . . . . . . . . . . 13                              fortran-column-ruler . . . . . . . . . . . . . . . . . . . . . . . . 36
diary-number-of-entries . . . . . . . . . . . . . . . . . . . . . 12                    fortran-column-ruler-fixed. . . . . . . . . . . . . . . . . . 37
diary-persian-date . . . . . . . . . . . . . . . . . . . . . . . . . . . 18             fortran-column-ruler-tabs . . . . . . . . . . . . . . . . . . . 37
diary-print-entries. . . . . . . . . . . . . . . . . . . . . . . . . . 15               fortran-comment-indent-char . . . . . . . . . . . . . . . . 35
diary-print-entries-hook . . . . . . . . . . . . . . . . . . . . 15                     fortran-comment-indent-style . . . . . . . . . . . . . . . 35
diary-remind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17     fortran-comment-line-extra-indent . . . . . . . . . 35
diary-sexp-entry-symbol . . . . . . . . . . . . . . . . . . . . . 16                    fortran-comment-line-start. . . . . . . . . . . . . . . . . . 34
diary-show-holidays-flag . . . . . . . . . . . . . . . . . . . . 12                     fortran-comment-region . . . . . . . . . . . . . . . . . . . . . . 35
diary-simple-display . . . . . . . . . . . . . . . . . . . . . . . . 15                 fortran-continuation-indent . . . . . . . . . . . . . . . . 34
diary-sort-entries . . . . . . . . . . . . . . . . . . . . . . . . . . . 16             fortran-continuation-string . . . . . . . . . . . . . . . . 32
diary-sunrise-sunset . . . . . . . . . . . . . . . . . . . . . . . . 18                 fortran-directive-re . . . . . . . . . . . . . . . . . . . . . . . . 35
directory listing on MS-DOS . . . . . . . . . . . . . . . . . . . 44                    fortran-do-indent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
dired-listing-switches (MS-DOS) . . . . . . . . . . . 44                                fortran-electric-line-number . . . . . . . . . . . . . . . 33
Index                                                                                                                                                                    55



fortran-end-of-block . . . . . . . . . . . . . . . . . . . . . . . . 31                 M
fortran-if-indent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34            M-^ (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
fortran-indent-subprogram . . . . . . . . . . . . . . . . . . . 32                      M-q (Fortran mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
fortran-join-line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32            M-TAB (Picture mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
fortran-line-length. . . . . . . . . . . . . . . . . . . . . . . . . . 36               making pictures out of text characters . . . . . . . . . . . 2
fortran-line-number-indent. . . . . . . . . . . . . . . . . . 33                        manual version backups . . . . . . . . . . . . . . . . . . . . . . . . 29
fortran-minimum-statement-indent... . . . . . . . 34                                    Mayan calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
fortran-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31     Mayan calendar round . . . . . . . . . . . . . . . . . . . . . . . . . 11
fortran-next-statement . . . . . . . . . . . . . . . . . . . . . . 31                   Mayan haab calendar . . . . . . . . . . . . . . . . . . . . . . . . . . 11
fortran-previous-statement. . . . . . . . . . . . . . . . . . 31                        Mayan long count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
fortran-split-line . . . . . . . . . . . . . . . . . . . . . . . . . . . 32             Mayan tzolkin calendar . . . . . . . . . . . . . . . . . . . . . . . . 11
fortran-strip-sequence-nos. . . . . . . . . . . . . . . . . . 37                        merge buffer (Emerge) . . . . . . . . . . . . . . . . . . . . . . . . . 20
fortran-structure-indent . . . . . . . . . . . . . . . . . . . . 34                     merging files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
fortran-tab-mode-default . . . . . . . . . . . . . . . . . . . . 32                     Meta (under MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . . 38
fortran-window-create . . . . . . . . . . . . . . . . . . . . . . . 37                  mode line (MS-DOS). . . . . . . . . . . . . . . . . . . . . . . . . . . 43
fortran-window-create-momentarily . . . . . . . . . 37                                  mode, Fortran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
frame size under MS-DOS . . . . . . . . . . . . . . . . . . . . . . 40                  mouse support under MS-DOS . . . . . . . . . . . . . . . . . 38
frames on MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40             mouse, set number of buttons . . . . . . . . . . . . . . . . . . 39
                                                                                        MS-DOS peculiarities . . . . . . . . . . . . . . . . . . . . . . . . . . 38
                                                                                        MS-Windows codepages . . . . . . . . . . . . . . . . . . . . . . . . 43
G                                                                                       msdos-set-mouse-buttons . . . . . . . . . . . . . . . . . . . . . 39
g m (Calendar mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
grep (MS-DOS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43         N
                                                                                        non-strict locking (RCS) . . . . . . . . . . . . . . . . . . . . . . . 29
H
holiday forms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9   O
holiday-bahai-holidays . . . . . . . . . . . . . . . . . . . . . . . 9                  omer count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
holiday-christian-holidays . . . . . . . . . . . . . . . . . . . 9
holiday-general-holidays . . . . . . . . . . . . . . . . . . . . . 9
holiday-hebrew-holidays . . . . . . . . . . . . . . . . . . . . . . 9                   P
holiday-islamic-holidays . . . . . . . . . . . . . . . . . . . . . 9                    parasha, weekly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
holiday-local-holidays . . . . . . . . . . . . . . . . . . . . . . . 9                  Picture mode and rectangles . . . . . . . . . . . . . . . . . . . . 4
holiday-oriental-holidays . . . . . . . . . . . . . . . . . . . . 8                     picture-backward-clear-column . . . . . . . . . . . . . . . 2
holiday-other-holidays . . . . . . . . . . . . . . . . . . . . . . . 9                  picture-backward-column . . . . . . . . . . . . . . . . . . . . . . 2
holiday-solar-holidays . . . . . . . . . . . . . . . . . . . . . . . 8                  picture-clear-column. . . . . . . . . . . . . . . . . . . . . . . . . . 2
HOME directory under MS-DOS . . . . . . . . . . . . . . . 41                            picture-clear-line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Hyper (under MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . 38                 picture-clear-rectangle . . . . . . . . . . . . . . . . . . . . . . 4
                                                                                        picture-clear-rectangle-to-register . . . . . . . . 4
                                                                                        picture-forward-column . . . . . . . . . . . . . . . . . . . . . . . 2
I                                                                                       picture-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
indent-tabs-mode (Fortran mode) . . . . . . . . . . . . .                        32     picture-mode-hook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
inferior processes under MS-DOS . . . . . . . . . . . . . . .                    43     picture-motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
init file, default name under MS-DOS . . . . . . . . . .                         40     picture-motion-reverse . . . . . . . . . . . . . . . . . . . . . . . 3
international support (MS-DOS) . . . . . . . . . . . . . . .                     42     picture-move-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
                                                                                        picture-move-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
                                                                                        picture-movement-down . . . . . . . . . . . . . . . . . . . . . . . . 3
                                                                                        picture-movement-left . . . . . . . . . . . . . . . . . . . . . . . . 3
L                                                                                       picture-movement-ne . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
language environment, automatic                                                         picture-movement-nw . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
  selection on MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . 42                picture-movement-right . . . . . . . . . . . . . . . . . . . . . . . 3
locking (CVS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30      picture-movement-se . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
locking, non-strict (RCS) . . . . . . . . . . . . . . . . . . . . . . . 29              picture-movement-sw . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
long file names in DOS box under                                                        picture-movement-up . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
  Windows 95/NT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41            picture-newline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
                                                                                        picture-open-line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
                                                                                        picture-set-tab-stops . . . . . . . . . . . . . . . . . . . . . . . . 4
Index                                                                                                                                                                     56



picture-tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4          V
picture-tab-chars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4                  vc-backend-header . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
picture-tab-search . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4                   vc-command-messages. . . . . . . . . . . . . . . . . . . . . . . . . . 28
picture-yank-rectangle . . . . . . . . . . . . . . . . . . . . . . . 4                         vc-consult-headers . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
picture-yank-rectangle-from-register . . . . . . . 4
                                                                                               vc-create-tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
pictures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
                                                                                               vc-cvs-global-switches . . . . . . . . . . . . . . . . . . . . . . 29
printing under MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . 43
                                                                                               vc-cvs-stay-local . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
                                                                                               vc-default-patch-addressee. . . . . . . . . . . . . . . . . . 28
                                                                                               vc-delete-file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Q                                                                                              vc-edit-next-command . . . . . . . . . . . . . . . . . . . . . . . . 27
quitting on MS-DOS . . . . . . . . . . . . . . . . . . . . . . . . . . . 38                    vc-follow-symlinks . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
                                                                                               vc-handled-backends. . . . . . . . . . . . . . . . . . . . . . . . . . 28
                                                                                               vc-insert-headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
R                                                                                              vc-make-backup-files . . . . . . . . . . . . . . . . . . . . . . . . 28
rectangles and Picture mode . . . . . . . . . . . . . . . . . . . . 4                          vc-prepare-patch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
remote repositories (CVS) . . . . . . . . . . . . . . . . . . . . . . 29                       vc-prepare-patches-separately . . . . . . . . . . . . . . 28
renaming version-controlled files . . . . . . . . . . . . . . . . 25                           vc-rename-file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
revision tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26        vc-retrieve-tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
rosh hodesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19         vc-static-header-alist . . . . . . . . . . . . . . . . . . . . . . 27
                                                                                               vc-suppress-confirm. . . . . . . . . . . . . . . . . . . . . . . . . . 28
                                                                                               vc-update-change-log . . . . . . . . . . . . . . . . . . . . . . . . 25
S
sexp diary entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
sorting diary entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16               W
Super (under MS-DOS) . . . . . . . . . . . . . . . . . . . . . . . . 38
symbolic links (and version control) . . . . . . . . . . . . 28                                Windows clipboard support . . . . . . . . . . . . . . . . . . . . 39


T                                                                                              Y
tags for version control . . . . . . . . . . . . . . . . . . . . . . . . . 26                  yahrzeits, and sexp diary entries. . . . . . . . . . . . . . . . 19