| GROPS(1) | General Commands Manual | GROPS(1) |
grops - PostScript driver for groff
grops |
[-glmv] [-b n] [-c n] [-F dir] [-I dir] [-p papersize] [-P prologue] [-w n] [file ...] |
grops translates the output of GNU troff to PostScript. Normally grops should be invoked by using the groff command with a -Tps option. (Actually, this is the default for groff.) If no files are given, grops reads the standard input. A filename of - also causes grops to read the standard input. PostScript output is written to the standard output. When grops is run by groff options can be passed to grops using groff's -P option.
Note that grops doesn't produce a valid document structure (conforming to the Document Structuring Convention) if called with multiple file arguments. To print such concatenated output it is necessary to deactivate DSC handling in the printing program or previewer. See section “Font Installation” below for a guide how to install fonts for grops.
Whitespace is permitted between a command-line option and its argument.
command in the DESC file. Otherwise the default value is 0.
The input to grops must be in the format output by troff(1). This is described in groff_out(5).
In addition, the device and font description files for the device used must meet certain requirements: The resolution must be an integer multiple of 72 times the sizescale. The ps device uses a resolution of 72000 and a sizescale of 1000.
The device description file must contain a valid paper size; see groff_font(5) for more information.
Each font description file must contain a command
which says that the PostScript name of the font is psname. It may also contain a command
which says that the PostScript font should be reencoded using the encoding described in enc_file; this file should consist of a sequence of lines of the form:
where pschar is the PostScript name of the character, and code is its position in the encoding expressed as a decimal integer; valid values are in the range 0 to 255. Lines starting with # and blank lines are ignored. The code for each character given in the font file must correspond to the code for the character in encoding file, or to the code in the default encoding for the font if the PostScript font is not to be reencoded. This code can be used with the \N escape sequence in troff to select the character, even if the character does not have a groff name. Every character in the font file must exist in the PostScript font, and the widths given in the font file must match the widths used in the PostScript font. grops assumes that a character with a groff name of space is blank (makes no marks on the page); it can make use of such a character to generate more efficient and compact PostScript output.
Note that grops is able to display all glyphs in a PostScript font, not only 256. enc_file (or the default encoding if no encoding file specified) just defines the order of glyphs for the first 256 characters; all other glyphs are accessed with additional encoding vectors which grops produces on the fly.
grops can automatically include the downloadable fonts necessary to print the document. Such fonts must be in PFA format. Use pfbtops(1) to convert a Type 1 font in PFB format. Any downloadable fonts which should, when required, be included by grops must be listed in the file /usr/share/groff/1.22.4/font/devps/download; this should consist of lines of the form
where font is the PostScript name of the font, and filename is the name of the file containing the font; lines beginning with # and blank lines are ignored; fields may be separated by tabs or spaces; filename is searched for using the same mechanism that is used for groff font metric files. The download file itself is also searched for using this mechanism; currently, only the first found file in the font path is used.
If the file containing a downloadable font or imported document conforms to the Adobe Document Structuring Conventions, then grops interprets any comments in the files sufficiently to ensure that its own output is conforming. It also supplies any needed font resources that are listed in the download file as well as any needed file resources. It is also able to handle inter-resource dependencies. For example, suppose that you have a downloadable font called Garamond, and also a downloadable font called Garamond-Outline which depends on Garamond (typically it would be defined to copy Garamond's font dictionary, and change the PaintType), then it is necessary for Garamond to appear before Garamond-Outline in the PostScript document. grops handles this automatically provided that the downloadable font file for Garamond-Outline indicates its dependence on Garamond by means of the Document Structuring Conventions, for example by beginning with the following lines
In this case both Garamond and Garamond-Outline would need to be listed in the download file. A downloadable font should not include its own name in a %%DocumentSuppliedResources comment.
grops does not interpret %%DocumentFonts comments. The %%DocumentNeededResources, %%DocumentSuppliedResources, %%IncludeResource, %%BeginResource, and %%EndResource comments (or possibly the old %%DocumentNeededFonts, %%DocumentSuppliedFonts, %%IncludeFont, %%BeginFont, and %%EndFont comments) should be used.
In the default setup there are styles called R, I, B, and BI mounted at font positions 1 to 4. The fonts are grouped into families A, BM, C, H, HN, N, P, and T having members in each of these styles:
There is also the following font which is not a member of a family:
There are also some special fonts called S for the PS Symbol font, and SS, containing slanted lowercase Greek letters taken from PS Symbol. Zapf Dingbats is available as ZD, and a reversed version of ZapfDingbats (with symbols pointing in the opposite direction) is available as ZDR; most characters in these fonts are unnamed and must be accessed using \N.
The default color for \m and \M is black; for colors defined in the ‘rgb’ color space setrgbcolor is used, for ‘cmy’ and ‘cmyk’ setcmykcolor, and for ‘gray’ setgray. Note that setcmykcolor is a PostScript LanguageLevel 2 command and thus not available on some older printers.
grops understands various X commands produced using the \X escape sequence; grops only interprets commands that begin with a ps: tag.
.nr x 1i
.de y
ps: exec
\nx u 0 rlineto
stroke
..
\Yy
is another way to draw a horizontal line one inch long. Note the single backslash before ‘nx’ – the only reason to use a number register while defining the macro ‘y’ is to convert a user-specified dimension ‘1i’ to internal groff units which are in turn converted to PS units with the u procedure.
grops wraps user-specified PostScript code into a dictionary, nothing more. In particular, it doesn't start and end the inserted code with save and restore, respectively. This must be supplied by the user, if necessary.
For example, gxditview is not able to display a proper \(em character because the standard X11 fonts do not provide it; this problem can be overcome by executing the following request
.char \(em \X'ps: invis'\
\Z'\v'-.25m'\h'.05m'\D'l .9m 0'\h'.05m''\
\X'ps: endinvis'\(em
In this case, gxditview is unable to display the \(em character and draws the line, whereas grops prints the \(em character and ignores the line (this code is already in file Xps.tmac which is loaded if a document intended for grops is previewed with gxditview).
If a PostScript procedure BPhook has been defined via a ‘ps: def’ or ‘ps: mdef’ device command, it is executed at the beginning of every page (before anything is drawn or written by groff). For example, to underlay the page contents with the word ‘DRAFT’ in light gray, you might use
.de XX
ps: def
/BPhook
{ gsave .9 setgray clippath pathbbox exch 2 copy
.5 mul exch .5 mul translate atan rotate pop pop
/NewCenturySchlbk-Roman findfont 200 scalefont setfont
(DRAFT) dup stringwidth pop -.5 mul -70 moveto show
grestore }
def
..
.devicem XX
Or, to cause lines and polygons to be drawn with square linecaps and mitered linejoins instead of the round linecaps and linejoins normally used by grops, use
.de XX
ps: def
/BPhook { 2 setlinecap 0 setlinejoin } def
..
.devicem XX
(square linecaps, as opposed to butt linecaps (0 setlinecap), give true corners in boxed tables even though the lines are drawn unconnected).
grops itself doesn't emit bounding box information. With the help of Ghostscript the following simple script, groff2eps, produces an encapsulated PS file.
#! /bin/sh groff -P-b16 $1 > $1.ps gs -dNOPAUSE -sDEVICE=bbox -- $1.ps 2> $1.bbox sed -e "/^%%Orientation/r $1.bbox" \
-e "/^%!PS-Adobe-3.0/s/$/ EPSF-3.0/" $1.ps > $1.eps rm $1.ps $1.bbox
Just say
to convert file foo to foo.eps.
TrueType fonts can be used with grops if converted first to Type 42 format, a special PostScript wrapper equivalent to the PFA format mentioned in pfbtops(1). There are several different methods to generate a type42 wrapper and most of them involve the use of a PostScript interpreter such as Ghostscript – see gs(1).
Yet, the easiest method involves the use of the application ttftot42(1). This program uses freetype(3) (version 1.3.1) to generate type42 font wrappers and well-formed AFM files that can be fed to the afmtodit(1) script to create appropriate metric files. The resulting font wrappers should be added to the download file. ttftot42 source code can be downloaded from ftp://www.giga.or.at/pub/nih/ttftot42/.
Another solution for creating type42 wrappers is to use FontForge, available from http://fontforge.sf.net. This font editor can convert most outline font formats.
This section gives a summary of the above explanations; it can serve as a step-by-step font installation guide for grops.
groff versions 1.19.2 and earlier contain a slightly different set of the 35 Adobe core fonts; the difference is mainly the lack of the ‘Euro’ glyph and a reduced set of kerning pairs. For backwards compatibility, these old fonts are installed also in the
directory.
To use them, make sure that grops finds the fonts before the default system fonts (with the same names): Either add command-line option -F to grops
or add the directory to groff's font path environment variable
afmtodit(1), groff(1), troff(1), pfbtops(1), groff_out(5), groff_font(5), groff_char(7), groff_tmac(5)
PostScript Language Document Structuring Conventions Specification
| 19 March 2021 | groff 1.22.4 |