| crm(1) | CRM114 | crm(1) |
crm - The Controllable Regex Mutilator
crm [OPTION]... CRMFILE
This man page is taken from an older CRM114 version. It is provided as a convenience to Debian users and may not be up-to-date. If you would like to update it, please send appropriate patches to the Debian bug tracking system.
-d N (enter debugger after running N cycles. Omitting N means N equals 0.)
CRM114 is a language designed to write filters in. It caters to filtering email, system log streams, html, and other marginally human-readable ASCII that may occasion to grace your computer.
CRM114's unique strengths are the data structure (everything is a string and a string can overlap another string), it's ability to work on truly infinitely long input streams, it's ability to use extremely advanced classifiers to sort text, and the ability to do approximate regular expressions (that is, regexes that don't quite match) via the TRE regex library.
CRM114 also sports a very powerful subprocess control facility, and a unique syntax and program structure that puts the fun back in programming (OK, you can run away screaming now). The syntax is declensional rather than positional; the type of quote marks around an argument determine what that argument will be used for.
The typical CRM114 program uses regex operations more often than addition (in fact, math was only added to TRE in the waning days of 2003, well after CRM114 had been in daily use for over a year and a half).
In other words, crm114 is a very very powerful mutagenic filter that happens to be a programming language as well.
The filtering style of the CRM-114 discriminator is based on the fact that most spam, normal log file messages, or other uninteresting data is easily categorized by a few characteristic patterns (such as "Mortgage leads", "advertise on the internet", and "mail-order toner cartridges".) CRM114 may also be useful to folks who are on multiple interlocking mailing lists.
In a bow to Unix-style flexibility, by default CRM114 reads it's input from standard input, and by default sends it's output to standard output. Note that the default action has a zero-length output. Redirection and use of other input or output files is possible, as well as the use of windowing, either delimiter-based or time-based, for real-time continuous applications.
CRM114 can be used for other than mail filtering; consider it to be a version of grep with super powers. If perl is a seventy-bladed swiss army knife, CRM114 is a razor-sharp katana that can talk.
Absent the -{ program } flag, the first argument is taken to be the name of a file containing a crm114 program, subsequent arguments are merely supplied as :_argN: values. Use single quotes around commandline programs '-{ like this }' to prevent the shell from doing odd things to your command-line programs.
CRM114 can be directly invoked by the shell if the first line of your program file uses the shell standard, as in:
#! /usr/bin/crm
You can use CRM114 flags on the shell-standard invocation line, and hide them with '--' from the program itself; '--' incidentally prevents the invoking user from changing any CRM114 invocation flags.
Flags should be located after any positional variables on the command line. Flags are visible as :_argN: variables, so you can create your own flags for your own programs (separate CRM114 and user flags with '--'). Two examples on how to do this:
./foo.crm bar mugga < baz -t -w 150000
./foo.crm -t -w 1500000 -- bar < baz mugga
One example on how not to do this:
./foo.crm -t -w 150000 bar < baz mugga
(That's WRONG!)
You can put a list of user-settable vars on the #!/usr/bin/crm invocation line. CRM114 will print these out when a program is invoked directly (e.g. "./myprog.crm -h", not "crm myprog.crm -h") with the -h (for help) flag. (note that this works ONLY on bash on Linux- *BSD's have a different bash interpretation and this doesn't work)
Example:
#!/usr/bin/crm -( var1 var2=A var2=B var2=C )
This allows only var1 and var2 be set on the command line. If a variable is not assigned a value, the user can set any value desired. If the variable is equated to a set of values, those are the only values allowed.
Another example:
#!/usr/bin/crm -( var1 var2=foo ) --
This allows var1 to be set to any value, var2 may only be set to either foo or not at all, and no other variables may be set nor may invocation flags be changed (because of the trailing "--"). Since "--" also blocks '-h' for help, such programs should provide their own help facility.
Variable names and locations start with a : , end with a : , and may contain only characters that have ink (i.e. the [:graph:] class) with few exceptions.
Examples :here:, :ThErE:, :every-where_0123+45%6789:, :this_is_a_very_very_long_var_name_that_does_not_tell_us_much:. Builtin variables:
:_nl: newline
:_ht: horizontal tab
:_bs: backspace
:_sl: a slash
:_sc: a semicolon
:_arg0: thru :_argN: command-line args, including all flags
:_argc: how many command line arguments there were
:_pos0: thru :_posN: positional args ('-' or '--' args deleted)
:_posc: how many positional arguments there were
:_pos_str: all positional arguments concatented
:_env_whatever: environment value 'whatever'
:_env_string: all environmental arguments concatenated
:_crm_version: the version of the CRM system
:_dw: the current data window contents
Variables are expanded by the :*: var-expansion operator, e.g. :*:_nl: expands to a newline character. Uninitialized vars evaluate to their text name (and the colons stay).
You can also use the standard constant C '\' characters, such as "\n" for newline, as well as excaped hexadecimal and octal characters like \xHH and \oOOO but these are constants, not variables, and cannot be redefined.
Depending on the value of "math mode" (flag -q). you can also use :#:string_or_var: to get the length of a string, and :@:string_or_var: to do basic mathematics and inequality testing, either only in EVALs or for all var-expanded expressions. See "Sequence of Evaluation" below for more details.
Default behavior is to read all of standard input till EOF into the default data window (named :_dw:), then execute the program (this is overridden if first executable statement is a WINDOW statement).
Variables don't get their own storage unless you ISOLATE them (see below), instead variables are start/length pairs indexing into the default data window. Thus, ALTERing an unISOLATEd variable changes the value of the default data buffer itself. This is a great power, so use it only for good, and never for evil.
Statements are separated with a ';' or with a newline.
\
'\' is the string-text escape character. You only need to escape the
literal representation of closing delimiters inside var-expanded
arguments.
You can use the classic C/C++ \-escapes, such as \n, \r, \t, \a, \b, \v, \f, \0, and also \xHH and \oOOO for hex and octal characters, respectively.
A '\' as the last character of a line means the next line is just a continuation of this one.
A \-escape that isn't recognized as something special isn't an error; you may optionally escape any of the delimiters >, ) ] } ; / # \ and get just that character.
A '\' anywhere else is just a literal backslash, so the regex
([abc])\1 is written just that way; there is no need to double-backslash the
\1 (although it will work if you do).
# this is a comment
# and this too \#
A comment is not a piece of preprocessor sugar -- it is a statement and
ends at the newline or at "\#".
insert filename
inserts the file verbatim at this line at compile time.
;
statement separator - must ALWAYS be escaped as \; unless it's inside
delimiters or else it will mark the end of the statement.
{ and }
start and end blocks of statements. Must always be '\' escaped or inside
delimiters or these will mark the start/end of a block.
noop
no-op statement
:label:
define a GOTOable label
accept
writes the current data window to standard output; execution continues.
alius
if the last bracket-group succeeded, ALIUS skips to end of {} block (a skip,
not a FAIL); if the prior group FAILed, ALIUS does nothing. Thus, ALIUS is
both an ELSE clause and a CASE statement.
alter (:var:) /new-val/
destructively change value of var to newval; (:var:) is var to change
(var-expanded); /new-val/ is value to change to (var-expanded).
classify <flags> (:c1:...|...:cN:) (:stats:) [:in:] /word-pat/
compare the statistics of the current data window buffer with classfiles
c1...cN.
<flags> If <flags> is set to <nocase>, ignore case in
word-pat, does not change case in hash (use tr() to do that on :in: if you
want it).
(:c1: ... file or files to consider "success" files. The CLASSIFY
succeeds if these files as a group match best. If not, the CLASSIFY does a
FAIL.
| optional separator. Spaces on each side of the " | " are required.
.... :cN:) optional files to the right of " | " are considered as a
group to "fail". If statement fails, execution skips to end of
enclosing {..} block, which exits with a FAIL status (see ALIUS for why this
is useful).
(:stats:) optional var that will get a text formatted matching summary
[:in:] restrict statistical measure to the string inside :in:
/word-pat/ regex to describe what a parseable word is.
eval (:result:) /instring/
repeatedly evaluates /instring/ until it ceases to change, then places that
result as the value of :result: . EVAL uses smart (but foolable) heuristics
to avoid infinite loops, like evaluating a string that evaluates to a
request to evaluate itself again. The error rate is about 1 / 2^62 and will
detect chain groups of length 255 or less. If the instring uses math
evaluation (see section below on math operations) and the evaluation has an
inequality test, (>, < or =) then if the inequality fails, the EVAL
will FAIL to the end of block. If the evaluation has a numeric fault (e.g.
divide-by-zero) the EVAL will do a TRAPpable FAULT.
exit /:retval:/
ends program execution. If supplied, the return value is converted to an
integer and returned as the exit code of the crm114 program. If no retval is
supplied, the return value is 0.
fail
skips down to end of the current { } block and causes that block to exit with
a FAIL status (see ALIUS for why this is useful)
fault /faultstr/
forces a FAULT with the given string as the reason. The fault string is
val-expanded.
goto /:label:/
unconditional branch (you can use a variable as the goal, e.g. /:*:there:/ )
hash (:result:) /input/
compute a fast 32-bit hash of the /input/, and ALTER :result: to the
hexadecimal hash value. HASH is not warranted to be constant across
major releases of CRM114, nor is it cryptographically secure.
(:result:) value that gets result.
/input/ string to be hashed (can contain expanded :*:vars:, defaults to the
data window :_dw:)
intersect (:out:) [:var1: :var2: ...]
makes :out: contain the part of the data window that is the intersection of
:var1 :var2: ... ISOLATEd vars are ignored. This only resets the value of
the captured variable, and does NOT alter any text in the data window.
isolate (:var:) /initial-value/
puts :var: into a data area outside of the data buffer; subsequent changes to
this var don't change the data buffer (though they may change the value of
any var subsequently set inside of this var). If the var already was
ISOLATED, this is a noop.
(:var:) name of ISOLATEd var (var-expanded)
/initial-value/ optional initial value for :var: (var-expanded). If no value
is supplied, the previous value is retained/copied.
input <flags> (:result:) [:filename:]
read in the content of filename. If no filename, then read stdin
<byline> read one line only
(:result:) var that gets the input value
[:filename:] the file to read
learn <flags> (:class:) [:in:] /word-pat/
learn the statistics of the :in: var (or the input window if no var) as an
example of class :class:
<flags> can be any of <nocase>, <refute> and
<microgroom>. <nocase>: ignore case in matching word-pat (does
not ignore case in hash- use tr() to do that on :in: if you want it).
<refute>: this is an anti-example of this class- unlearn it!
<microgroom>: enable the microgroomer to purge less-important
information automatically whenever the statistics file gets to crowded.
(:class:) name of file holding hashed results; nominal file extension is .css
[:in:] captured var containing the text to be learned (if omitted, the full
contents of the data window is used)
/word-pat/ regex that defines a "word". Things that aren't
"words" are ignored.
liaf
skips UP to START of the current {} block (LIAF is FAIL spelled backwards)
match <flags> (:var1: ...) [:in:] /regex/
Attempt to match the given regex; if match succeds, variables are bound; if
match fails, program skips to the closing '}' of this block
<flags> flags can be any of
<absent> statement succeeds if match not present
<nocase> ignore case when matching
<fromstart> start match at start of the [:in:] var
<fromcurrent> start match at start of previous successful match on the
[:in:] var
<fromnext> start match at one character past the start of the previous
successful match on the [:in:] var
<fromend> start match at one character past the end of prev. match on
this [:in:] var
<newend> require match to end after end of prev. match on this [:in:]
var
<backwards> search backward in the [:in:] variable from the last
successful match.
<nomultiline> don't allow this match to span lines
(:var1: ...) optional variables to bind to regex result and '(' ')' subregexes
[:in:] search only in the variable specified; if omitted, :_dw: (the full
input data window) is used
/regex/ POSIX regex (with \ escapes as needed)
If you build CRM114 to use the GNU regex library for MATCHing, be warned that
GNU REGEX has numerous issues. See the KNOWN_BUGS file for a detailed
listing.
output <flags> [filename] /output-text/
output an arbitrary string with captured values expanded.
<flags> <append>: append to the file (otherwise, overwrites)
[filename] filename to send output (var-expanded), default output is to stdout
/output-text/ string to output (var-expanded)
syscall <flags> (:in:) (:out:) (:status:) /command/
execute a shell command
<flags> can be any of <keep> and <async>. <keep>: keep
this process around; if kept, then a syscall with the same :keep: var will
continue feeding to and reading from the kept proc. <async>: don't
wait for process to send an EOF; just grab what's available in the process's
output pipe and proceed (limit per syscall is 256 Kbytes)
(:in:) var-expanded string to feed to command as input (can be null if you
don't want to send the process something.) You must specify this if
you want to specify an :out: variable.
(:out:) var-expanded varname to place results into (must pre-exist, can
be null if you don't want to read the process's output (yet, or at all).
Limit per syscall is 256 Kbytes. You must specify this if you want to
use the :status: variable)
(:status:) if you want to keep a minion proc around, or catch the exit status
of the process, specify a var here. The minion process's PID and pipes will
be stored here. The program can access the proc again with another syscall
by using this var again. When the process exits, it's exit code will be
stored here.
trap (:reason:) /trap_regex/
traps faults from both FAULT statements and program errors occurring anywhere
in the preceding bracket-block. If no fault exists, TRAP does a SKIP to end
of block. If there is a fault and the fault reason string matches the
trap_regex, the fault is trapped, and execution continues with the line
after the TRAP, otherwise the fault is passed up to the next surrounding
trapped bracket block.
(:reason:) the fault message that caused this FAULT. If it was a user fault,
this is the text the user supplied in the FAULT statement.
/trap_regex/ the regex that determines what kind of faults this TRAP will
accept. Putting a wildcard here (e.g. /.*/ means that ALL faults will be
trapped here.
union (:out:) [:var1: :var2: ...]
makes :out: contain the union of the data window segments that contains var1,
var2... plus any intervening text as well. Any ISOLATEd var is ignored. This
is non-surgical, and does not alter the data window
window <flags> (:w-var:) (:s-var:) /cut-regex/ /add-regex/
window slider. This deletes to and including the cut-regex from :var:
(default: use the data window), then reads adds from std. input till
add-regex (inclusive).
<flags> flags can be any of
<nocase> ignore case when matching cut- and add- regexes
<bychar> check input for add-regex every character
<byline> check input for add-regex every line
<byeof> wait for EOF to check for add-regex (extra characters are kept
around for later)
<eofends> read lots of input; the input is up to the regex match OR the
contents till EOF
(:w-var:) what var to window
(:s-var:) what var to use for source (defaults to stdin, if you use a source
var you must specify the windowed var.
/cut-regex/ var-expanded cut pattern
/add-regex/ var-expanded add pattern, if absent reads till EOF
If both cut-regex and add-regex are omitted, and this window statement is the
first executable statement in the program, then CRM114 does
not wait to read a anything from standard input input before starting
program execution.
A regex is a pattern match. Do a "man 7 regex" for details.
Matches are, by default "first starting point that matches, then longest match possible that can fit".
a through z
A through Z
0 through 9
all match themselves.
most punctuation
matches itself, but check below!
*
repeat preceding 0 or more times
+
repeat preceding 1 or more times
?
repeat preceding 0 or 1 time
*?, +?, ??
repeat preceding, but shortest match that fits, given the
already-selected start point of the regex. (only supported by TRE regex, not
GNU regex)
[abcde]
any one of the letters a, b, c, d, or e
[a-q]
the letters a through q (just one of them)
{n,m}
repetition count: match the preceding at least n and no more than m times
(POSIX restricts this to a maximum of 255 repeats)
[[:<:]]
matches at the start of a word (GNU regex only)
[[:>:]]
matches the end of a word (GNU regex only)
^
as first char of a match, matches the start of a line (ONLY in
<nomultiline> matches.
$
as last char of a match, matches at the end of a line (ONLY in
<nomultiline> matches)
.
(a period) matches any single character (except start-of-line or end of line
"virtual characters", but it does match a newline).
a|b
match a or b
(match)
the () go away, and the string that matched inside is available for capturing.
Use \\( and \\) to match actual parenthesis (the first '\' tells "show
the second '\' to the regex engine, the second '\' forces a literalization
onto the parenthesis character.
\n
matches the N'th parenthesized subexpression. Remember to backslash-escape the
backslash (e.g. write this as \\1) This is only if you're using TRE, not GNU
regex.
The following are other POSIX expressions, which mostly do what you'd guess
they'd do from their names.
[[:alnum:]]
[[:alpha:]]
[[:blank:]]
[[:cntrl:]]
[[:digit:]]
[[:lower:]]
[[:upper:]]
[[:graph:]]
[[:print:]]
[[:punct:]]
[[:space:]]
[[:xdigit:]]
[[:graph:]] matches any character that puts ink on paper or lights a pixel. [[:print:]] matches any character that moves the "print head" or cursor.
By default, CRM114 supports string length and mathematical evaluation only in an EVAL statement, although it can be set to allow these in any place where a var-expanded variable is allowed (see the -q flag). The default value ( zero ) allows stringlength and math evaluation only in EVAL statements, and uses non-precedence (that is, strict left-to-right unless parenthesis are used) algebraic notation. -q 1 uses RPN instead of algebraic, again allowing stringlength and math evaluation only in EVAL expressions. Modes 2 and 3 allow stringlength and math evaluation in any var-expanded expression, with non-precedence algebraic notation and RPN notation respectively. Evaluation is always left-to-right; there is no precedence of operators beyond the sequential passes noted below. The evaluation is done in four sequential passes:
1 \-constants like \n, \o377 and \x3F are substituted
2 :*:var: variables are substituted (note the difference between a constant
like '\n' and a variable like ":*:_nl:" here - constants are
substituted first, then variables are substituted.)
3 :#:var: string-length operations are performed
4 :@:expression: mathematical expressions are performed; syntax is either RPN
or non-precedenced (parens required) algebraic notation. Embedded
non-evaluated strings in a mathematical expression is currently a no-no.
Allowed operators are: + - * / % > < = only.
Only >, <, and = set logical results; they also evaluate to 1 and 0 for continued chain operations - e.g.
((:*:a: > 3) + (:*:b: > 5) + (:*:c: > 9) > 2)
is true IFF any of the following is true
• a > 3 and b > 5
• a > 3 and c > 9
• b > 5 and c > 9
Only the TRE engine supports approximate matching. The GNU engine does not support approximate matching.
Approximate matching is specified similarly to a "repetition count" in a regular regex, using brackets. This approximation applies to the previous parenthesized expression (again, just like repetion counts). You can specify maximum total changes, and how many inserts, deletes, and substitutions you wish to allow. The minimum-error match is found and reported, if it exists within the bounds you state.
The basic syntax is:
(text-to-match){~[maxerrs] [#maxsubsts] [+maxinserts] [-maxdeletes]}
Note that the '~' (with an optional maxerr count) is required (that's how we know it's an approximate regex rather than just a rep-count); if you don't specify a max error count, you will get the best match, if you do, the match will have at most that many errors.
Remember that you specify the changes to the text in the pattern necessary to make it match the text in the string being searched.
You cannot use approximate regexes and backrefs (like \1) in the same regex. This is a limitation of in TRE at this point.
You can also use an inequality in addition to the basic syntax above:
(text-to-match){~[maxerrs] [basic-syntax] [nI + mD + oS < K] }
where n, m, and o are the costs per insertion, deletion, and substitution respectively, 'I', 'D', and 'S' are indicators to tell which cost goes with which kind of error, and K is the total cost of the errors; the cost of the errors is always strictly less than K. Here are some examples.
(foobar)
exactly matches "foobar"
(foobar){~}
finds the closest match to "foobar", with the minimum number of
inserts, deletes, and substitutions. Always succeeds.
(foobar){~3}
finds the closest match to "foobar", with no more than 3 inserts,
deletes, or substitutions
(foobar){~2 +2 -1 #1)
find the closest match to "foobar", with at most two errors total,
and at most two inserts, one delete, and one substitution.
(foobar){~4 #1 1i + 2d < 5 }
find the closest match to "foobar", with at most four errors total,
at most one substitution, and with the number of insertions plus 2x the
number of deletions less than 5.
(foo){~1}(bar){~1)
find the closest match to "foobar", with at most one error in the
"foo" and one error in the "bar".
Here's how to remember what goes where in the CRM114 language.
Unlike most computer languages, CRM114 uses inflection (or declension) rather than position to describe what role each part of a statement plays. The declensions are marked by the delimiters- the /, ( and ), < and >, and [ and ].
By and large, you can mix up the arguments to each kind of statement without changing their meaning. Only the ACTION needs to be first. Other parts of the statement can occur in any order, save that multiple (paren_args) and /pattern_args/ must stay in their nominal order but can go anywhere in the statement. They do not need to be consecutive.
The parts of a CRM114 statement are:
ACTION the verb. This is at the start of the statement.
/pattern/ the overall pattern the verb should use, analogous to the
"subject" of the statement.
<flags> modifies how the ACTION does the work. You'd call these
"adverbs" in human languages.
(vars) what variables to use as adjuncts in the action (what would be called
the "direct objects"). These can get changed when the action
happens.
[limited-to] where the action is allowed to take place (think of it as the
"indirect object"). These are not directly changed by the action.
cssmerge(1), cssdiff(1), cssutil(1)
The CRM114 homepage is at http://crm114.sf.net/ .
This manpage: $Id: crm114.azm,v 1.12 2004/08/19 11:10:49 vanbaal Exp $
This manpage describes the crm114 utility as it has been described by QUICKREF.txt, shipped with crm114-20040212-BlameJetlag.src.tar.gz. The DESCRIPTION section is copy-and-pasted from INTRO.txt as distributed with the same source tarball.
Converted from plain ascii to zoem by Joost van Baal.
Copyright (C) 2001, 2002, 2003, 2004 William S. Yerazunis
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program (see COPYING); if not, check with http://www.gnu.org/copyleft/gpl.html or write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
William S. Yerazunis. Manpage typesetting by Joost van Baal and Shalendra Chhabra
| 19 Aug 2004 | crm114 20040816.BlameClockworkOrange-auto.3 |