X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=doc%2Fpcrs.3;h=372073d9f7f34529f49036791809e8a0184f24d7;hp=d5d202203bac5afd191cf73d94ef26f173cbf84f;hb=cbd8da07adad27663478d7f66615cb3b89727a22;hpb=9353f7d279365ee2fa51b6f38c160ae1dc07a52f diff --git a/doc/pcrs.3 b/doc/pcrs.3 index d5d20220..372073d9 100644 --- a/doc/pcrs.3 +++ b/doc/pcrs.3 @@ -1,4 +1,4 @@ -.\" Copyright (c) 2001 Andreas S. Oesterhelt +.\" Copyright (c) 2001-2003 Andreas S. Oesterhelt .\" .\" This is free documentation; you can redistribute it and/or .\" modify it under the terms of the GNU General Public License as @@ -17,18 +17,18 @@ .\" .\" You should have received a copy of the GNU General Public .\" License along with this manual; if not, write to the Free -.\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, -.\" USA. +.\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, +.\" MA 02111, USA. .\" -.TH PCRS 3 "4 March 2002" +.TH PCRS 3 "2 December 2003" "pcrs-0.0.3" .SH NAME pcrs - Perl-compatible regular substitution. .SH SYNOPSIS .br -.BI "#include " +.B "#include " .PP .br -.BI "pcrs_job *pcrs_compile(const char *" pattern "," +.BI "pcrs_job *pcrs_compile(const char *" pattern "," .ti +5n .BI "const char *" substitute ", const char *" options , .ti +5n @@ -68,7 +68,7 @@ pcrs - Perl-compatible regular substitution. The .SM PCRS -library is a supplement to the +library is a supplement to the .SB PCRE(3) library that implements .RB "regular expression based substitution, like provided by " Perl(1) "'s 's'" @@ -77,10 +77,10 @@ differences (see below). In a first step, the information on a substitution, i.e. the pattern, the substitute and the options are compiled from Perl syntax to an internal form -.RB "called " pcrs_job " by using either the " pcrs_compile() " or " +.RB "called " pcrs_job " by using either the " pcrs_compile() " or " .BR pcrs_compile_command() " functions." -Once the job is compiled, it can be used on subjects, which are arbitrary +Once the job is compiled, it can be used on subjects, which are arbitrary memory areas containing string or binary data, by calling .BR pcrs_execute() ". Jobs can be chained to joblists and whole" .RB "joblists can be applied to a subject using " pcrs_execute_list() . @@ -104,7 +104,7 @@ There are also convenience functions for freeing the jobs and for errno-to-strin .RB "follows the '" "s" "' will be used as the delimiter. Patterns or substitutes" that contain the delimiter need to quote it: \fBs/th\\/is/th\\/at/\fR -.RB "will replace " "th/is" " by " "th/at" " and can be written more simply as" +.RB "will replace " "th/is" " by " "th/at" " and can be written more simply as" .BR "s|th/is|th/at|" "." .IR "pattern" ", " "substitute" ", " "options" " and " "command" " must be" @@ -123,7 +123,7 @@ On success, both functions return a pointer to the compiled job. .SS Substitutes .RI "The " "substitute" " uses" .RB "Perl syntax as documented in the " "perlre(1)" " manual page, with" -some exceptions: +some exceptions: Most notably and evidently, since .SM PCRS @@ -147,9 +147,9 @@ refers to what the last capturing subpattern matched. if a global substitution previously matched. .PP -Perl4-style references to subpattern matches of the form +Perl4-style references to subpattern matches of the form \fB\\1, \\2, ...\fR -.RB "which only exist in Perl5 for backwards compatibility, are " "not" +.RB "which only exist in Perl5 for backwards compatibility, are " "not" supported. Also, since the substitute is a double-quoted string in Perl, you @@ -251,21 +251,26 @@ Unsupported options are silently ignored. .RI "The first " subject_length " bytes following " subject " are processed, so" .RI "a " subject_length " that exceeds the actual " subject " is dangerous." -Note that if you want to get your zero-terminated C strings back including their -.RI "termination, you must let " subject_length " include the binary zero, i.e." -set it to -.BI strlen( subject ") + 1." +.RI "Note that for zero-terminated C strings, you should set " subject_length " to" +.BI strlen( subject ) \fR, +so that the dollar metacharacter matches at the end of the string, not after +the string-terminating null byte. For convenience, an extra null byte is +appended to the result so it can again be used as a string. .RI "The " subject " itself is left untouched, and the " *result " is dynamically" .RB "allocated, so it is the caller's responsibility to " free() " it when it's" no longer needed. -.RI "The result's length is written to " *result_length "." +.RI "The result's length (excluding the extra null byte) is written to " *result_length "." .RB "If the job matched, the " PCRS_SUCCESS " flag in" .IB job ->flags is set. + +.SS String subjects +If your + .SS Return value and diagnostics .RB "On success, " pcrs_execute() " returns the number of substitutions that" @@ -293,7 +298,7 @@ contains pointers to other dynamically allocated structures. Chaining the jobs is up to you, but once you have built a linked list of jobs, .RI "you can execute a whole " joblist " on a given subject by" .RB "a single call to " pcrs_execute_list() ", which will sequentially traverse" -.RB "the linked list until it reaches a " NULL " pointer, and call " pcrs_execute() +.RB "the linked list until it reaches a " NULL " pointer, and call " pcrs_execute() .RI "for each job it encounters, feeding the " result " and " result_length " of each" .RI "call into the next as the " subject " and " subject_length ". As in the single" .RI "job case, the original " subject " remains untouched, but all interim " result "s" @@ -330,22 +335,22 @@ Under normal circumstances, it can take the following values: While compiling the pattern, .SM PCRE ran out of memory. -.TP +.TP .B PCRS_ERR_NOMEM While compiling the job, .SM PCRS ran out of memory. -.TP +.TP .B PCRS_ERR_CMDSYNTAX .BR pcrs_compile_command() " didn't find four tokens while parsing the" .IR command . -.TP +.TP .B PCRS_ERR_STUDY A .SM PCRE .RB "error occured while studying the compiled pattern. Since " pcre_study() only provides textual diagnostic information, the details are lost. -.TP +.TP .B PCRS_WARN_BADREF .RI "The " substitute " contains a reference to a capturing subpattern that" .RI "has a higher index than the number of capturing subpatterns in the " pattern @@ -363,12 +368,12 @@ While matching the pattern, ran out of memory. This can only happen if there are more than 33 backrefrences .RI "in the " pattern "(!)" .BR and " memory is too tight to extend storage for more." -.TP +.TP .B PCRS_ERR_NOMEM While executing the job, .SM PCRS ran out of memory. -.TP +.TP .B PCRS_ERR_BADJOB .RB "The " pcrs_job "* passed to " pcrs_execute " was NULL, or the" .RB "job is bogus (it contains " NULL " pointers to the compiled @@ -405,7 +410,8 @@ int main(int Argc, char **Argv) { pcrs_job *job; char *result; - int newsize, err; + size_t newsize; + int err; if (Argc != 3) { @@ -415,12 +421,12 @@ int main(int Argc, char **Argv) if (NULL == (job = pcrs_compile_command(Argv[1], &err))) { - printf("Compile error: %s (%d).\\n", pcrs_strerror(err), err); + fprintf(stderr, "%s: compile error: %s (%d).\\n", Argv[0], pcrs_strerror(err), err); } - if (0 > (err = pcrs_execute(job, Argv[2], strlen(Argv[2]) + 1, &result, &newsize))) + if (0 > (err = pcrs_execute(job, Argv[2], strlen(Argv[2]), &result, &newsize))) { - printf("Exec error: %s (%d).\\n", pcrs_strerror(err), err); + fprintf(stderr, "%s: exec error: %s (%d).\\n", Argv[0], pcrs_strerror(err), err); } else { @@ -445,6 +451,10 @@ The number of capturing subpatterns is currently limited to 33, which is a Bad Thing[tm]. It should be dynamically expanded until it reaches the .SM PCRE limit of 99. +.br +This limitation is particularly embarassing since +.SM PCRE +3.5 has raised the capturing subpattern limit to 65K. All of the above values can be adjusted in the "Capacity" section .RB "of " pcrs.h "." @@ -458,8 +468,8 @@ and should be considered high risk. .SH HISTORY .SM PCRS -was originally written for the Internet Junkbuster project -(http://sourceforge.net/projects/ijbswa/). +was originally written for the Privoxy project +(https://www.privoxy.org/). .SH SEE ALSO .B PCRE(3), perl(1), perlre(1) @@ -467,12 +477,15 @@ was originally written for the Internet Junkbuster project .SH AUTHOR .SM PCRS -is Copyright 2000, 2001 by Andreas Oesterhelt and is -licensed under the terms of the GNU Lesser General Public License (LGPL), -version 2.1, which should be included in this distribution, with the exception -that the permission to replace that license with the GNU General Public -License (GPL) given in section 3 is restricted to version 2 of the GPL. - -If it is missing from this distribution, the LGPL can be obtained from -http://www.gnu.org/licenses/lgpl.html or by mail: Write to the Free Software -Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +is Copyright 2000 - 2003 by Andreas Oesterhelt +and 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. + +The GNU General Public License should be included with this file. +If not, you can view it at https://www.gnu.org/copyleft/gpl.html or write +to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA.