1318 lines
39 KiB
C
1318 lines
39 KiB
C
const char pcrs_rcs[] = "$Id: pcrs.c,v 1.29 2007/09/22 16:17:19 fabiankeil Exp $";
|
||
/*********************************************************************
|
||
*
|
||
* File : $Source: /cvsroot/ijbswa/current/pcrs.c,v $
|
||
*
|
||
* Purpose : pcrs is a supplement to the pcre library by Philip Hazel
|
||
* <ph10@cam.ac.uk> and adds Perl-style substitution. That
|
||
* is, it mimics Perl's 's' operator. See pcrs(3) for details.
|
||
*
|
||
* WARNING: This file contains additional functions and bug
|
||
* fixes that aren't part of the latest official pcrs package
|
||
* (which apparently is no longer maintained).
|
||
*
|
||
* Copyright : Written and Copyright (C) 2000, 2001 by Andreas S. Oesterhelt
|
||
* <andreas@oesterhelt.org>
|
||
*
|
||
* Copyright (C) 2006, 2007 Fabian Keil <fk@fabiankeil.de>
|
||
*
|
||
* This program is free software; you can redistribute it
|
||
* and/or modify it under the terms of the GNU Lesser
|
||
* General Public License (LGPL), version 2.1, which should
|
||
* be included in this distribution (see LICENSE.txt), 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.
|
||
*
|
||
* 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 license for more details.
|
||
*
|
||
* The GNU Lesser General Public License should be included
|
||
* with this file. If not, you can view it at
|
||
* http://www.gnu.org/licenses/lgpl.html
|
||
* or write to the Free Software Foundation, Inc., 59
|
||
* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
||
*
|
||
* Revisions :
|
||
* $Log: pcrs.c,v $
|
||
* Revision 1.29 2007/09/22 16:17:19 fabiankeil
|
||
* Move our includes below system includes to prevent macro conflicts.
|
||
*
|
||
* Revision 1.28 2007/08/18 14:37:27 fabiankeil
|
||
* Ditch hex_to_byte() in favour of xtoi().
|
||
*
|
||
* Revision 1.27 2007/08/05 13:47:04 fabiankeil
|
||
* #1763173 from Stefan Huehner: s@const static@static const@.
|
||
*
|
||
* Revision 1.26 2007/07/01 13:29:54 fabiankeil
|
||
* Add limited hex notation support for the PCRS
|
||
* substitution text ('\x7e' = '~'). Closes #1627140.
|
||
*
|
||
* Revision 1.25 2007/04/30 15:02:18 fabiankeil
|
||
* Introduce dynamic pcrs jobs that can resolve variables.
|
||
*
|
||
* Revision 1.24 2007/01/05 15:46:12 fabiankeil
|
||
* Don't use strlen() to calculate the length of
|
||
* the pcrs substitutes. They don't have to be valid C
|
||
* strings and getting their length wrong can result in
|
||
* user-controlled memory corruption.
|
||
*
|
||
* Thanks to Felix Gr<47>bert for reporting the problem
|
||
* and providing the fix [#1627140].
|
||
*
|
||
* Revision 1.23 2006/12/29 17:53:05 fabiankeil
|
||
* Fixed gcc43 conversion warnings.
|
||
*
|
||
* Revision 1.22 2006/12/24 17:34:20 fabiankeil
|
||
* Add pcrs_strerror() message for PCRE_ERROR_MATCHLIMIT
|
||
* and give a hint why an error code might be unknown.
|
||
*
|
||
* Catch NULL subjects early in pcrs_execute().
|
||
*
|
||
* Revision 1.21 2006/07/18 14:48:47 david__schmidt
|
||
* Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
|
||
* with what was really the latest development (the v_3_0_branch branch)
|
||
*
|
||
* Revision 1.19.2.4 2005/05/07 21:50:55 david__schmidt
|
||
* A few memory leaks plugged (mostly on error paths)
|
||
*
|
||
* Revision 1.19.2.3 2003/12/04 12:32:45 oes
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||
* Append a trailing nullbyte to result to facilitate string processing
|
||
*
|
||
* Revision 1.19.2.2 2002/10/08 16:22:28 oes
|
||
* Bugfix: Need to check validity of backreferences explicitly,
|
||
* because when max_matches are reached and matches is expanded,
|
||
* realloc() does not zero the memory. Fixes Bug # 606227
|
||
*
|
||
* Revision 1.19.2.1 2002/08/10 11:23:40 oes
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||
* Include prce.h via project.h, where the appropriate
|
||
* source will have been selected
|
||
*
|
||
* Revision 1.19 2002/03/08 14:47:48 oes
|
||
* Cosmetics
|
||
*
|
||
* Revision 1.18 2002/03/08 14:17:14 oes
|
||
* Fixing -Wconversion warnings
|
||
*
|
||
* Revision 1.17 2002/03/08 13:45:48 oes
|
||
* Hiding internal functions
|
||
*
|
||
* Revision 1.16 2001/11/30 21:32:14 jongfoster
|
||
* Fixing signed/unsigned comparison (Andreas please check this!)
|
||
* One tab->space
|
||
*
|
||
* Revision 1.15 2001/09/20 16:11:06 steudten
|
||
*
|
||
* Add casting for some string functions.
|
||
*
|
||
* Revision 1.14 2001/09/09 21:41:57 oes
|
||
* Fixing yet another silly bug
|
||
*
|
||
* Revision 1.13 2001/09/06 14:05:59 oes
|
||
* Fixed silly bug
|
||
*
|
||
* Revision 1.12 2001/08/18 11:35:00 oes
|
||
* - Introduced pcrs_strerror()
|
||
* - made some NULL arguments non-fatal
|
||
* - added support for \n \r \e \b \t \f \a \0 in substitute
|
||
* - made quoting adhere to standard rules
|
||
* - added warning for bad backrefs
|
||
* - added pcrs_execute_list()
|
||
* - fixed comments
|
||
* - bugfix & cosmetics
|
||
*
|
||
* Revision 1.11 2001/08/15 15:32:03 oes
|
||
* - Added support for Perl's special variables $+, $' and $`
|
||
* - Improved the substitute parser
|
||
* - Replaced the hard limit for the maximum number of matches
|
||
* by dynamic reallocation
|
||
*
|
||
* Revision 1.10 2001/08/05 13:13:11 jongfoster
|
||
* Making parameters "const" where possible.
|
||
*
|
||
* Revision 1.9 2001/07/18 17:27:00 oes
|
||
* Changed interface; Cosmetics
|
||
*
|
||
* Revision 1.8 2001/06/29 21:45:41 oes
|
||
* Indentation, CRLF->LF, Tab-> Space
|
||
*
|
||
* Revision 1.7 2001/06/29 13:33:04 oes
|
||
* - Cleaned up, renamed and reordered functions,
|
||
* improved comments
|
||
* - Removed my_strsep
|
||
* - Replaced globalflag with a general flags int
|
||
* that holds PCRS_GLOBAL, PCRS_SUCCESS, and PCRS_TRIVIAL
|
||
* - Introduced trivial option that will prevent pcrs
|
||
* from honouring backreferences in the substitute,
|
||
* which is useful for large substitutes that are
|
||
* red in from somewhere and saves the pain of escaping
|
||
* the backrefs
|
||
* - Introduced convenience function pcrs_free_joblist()
|
||
* - Split pcrs_make_job() into pcrs_compile(), which still
|
||
* takes a complete s/// comand as argument and parses it,
|
||
* and a new function pcrs_make_job, which takes the
|
||
* three separate components. This should make for a
|
||
* much friendlier frontend.
|
||
* - Removed create_pcrs_job() which was useless
|
||
* - Fixed a bug in pcrs_execute
|
||
* - Success flag is now handled by pcrs instead of user
|
||
*
|
||
* Revision 1.6 2001/06/03 19:12:45 oes
|
||
* added FIXME
|
||
*
|
||
* Revision 1.5 2001/05/29 09:50:24 jongfoster
|
||
* (Fixed one int -> size_t)
|
||
*
|
||
* Revision 1.4 2001/05/25 14:12:40 oes
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||
* Fixed bug: Empty substitutes now detected
|
||
*
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||
* Revision 1.3 2001/05/25 11:03:55 oes
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||
* Added sanity check for NULL jobs to pcrs_exec_substitution
|
||
*
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||
* Revision 1.2 2001/05/22 18:46:04 oes
|
||
*
|
||
* Added support for PCRE_UNGREEDY behaviour to pcrs,
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||
* which is selected by the (nonstandard and therefore
|
||
* capital) letter 'U' in the option string.
|
||
* It causes the quantifiers to be ungreedy by default.
|
||
* Appending a ? turns back to greedy (!).
|
||
*
|
||
* Revision 1.1.1.1 2001/05/15 13:59:02 oes
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||
* Initial import of version 2.9.3 source tree
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||
*
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||
*
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||
*********************************************************************/
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||
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||
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||
#include <string.h>
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||
#include <ctype.h>
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||
#include <assert.h>
|
||
|
||
/*
|
||
* Include project.h just so that the right pcre.h gets
|
||
* included from there
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||
*/
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||
#include "project.h"
|
||
|
||
/* For snprintf only */
|
||
#include "miscutil.h"
|
||
/* For xtoi */
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||
#include "encode.h"
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||
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||
#include "pcrs.h"
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||
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||
const char pcrs_h_rcs[] = PCRS_H_VERSION;
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||
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||
/*
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||
* Internal prototypes
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||
*/
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||
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||
static int pcrs_parse_perl_options(const char *optstring, int *flags);
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||
static pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag,
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||
int capturecount, int *errptr);
|
||
static int is_hex_sequence(const char *sequence);
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_strerror
|
||
*
|
||
* Description : Return a string describing a given error code.
|
||
*
|
||
* Parameters :
|
||
* 1 : error = the error code
|
||
*
|
||
* Returns : char * to the descriptive string
|
||
*
|
||
*********************************************************************/
|
||
const char *pcrs_strerror(const int error)
|
||
{
|
||
if (error < 0)
|
||
{
|
||
switch (error)
|
||
{
|
||
/* Passed-through PCRE error: */
|
||
case PCRE_ERROR_NOMEMORY: return "(pcre:) No memory";
|
||
|
||
/* Shouldn't happen unless PCRE or PCRS bug, or user messed with compiled job: */
|
||
case PCRE_ERROR_NULL: return "(pcre:) NULL code or subject or ovector";
|
||
case PCRE_ERROR_BADOPTION: return "(pcre:) Unrecognized option bit";
|
||
case PCRE_ERROR_BADMAGIC: return "(pcre:) Bad magic number in code";
|
||
case PCRE_ERROR_UNKNOWN_NODE: return "(pcre:) Bad node in pattern";
|
||
|
||
/* Can't happen / not passed: */
|
||
case PCRE_ERROR_NOSUBSTRING: return "(pcre:) Fire in power supply";
|
||
case PCRE_ERROR_NOMATCH: return "(pcre:) Water in power supply";
|
||
|
||
#ifdef PCRE_ERROR_MATCHLIMIT
|
||
/*
|
||
* Only reported by PCRE versions newer than our own.
|
||
*/
|
||
case PCRE_ERROR_MATCHLIMIT: return "(pcre:) Match limit reached";
|
||
#endif /* def PCRE_ERROR_MATCHLIMIT */
|
||
|
||
/* PCRS errors: */
|
||
case PCRS_ERR_NOMEM: return "(pcrs:) No memory";
|
||
case PCRS_ERR_CMDSYNTAX: return "(pcrs:) Syntax error while parsing command";
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||
case PCRS_ERR_STUDY: return "(pcrs:) PCRE error while studying the pattern";
|
||
case PCRS_ERR_BADJOB: return "(pcrs:) Bad job - NULL job, pattern or substitute";
|
||
case PCRS_WARN_BADREF: return "(pcrs:) Backreference out of range";
|
||
case PCRS_WARN_TRUNCATION:
|
||
return "(pcrs:) At least one variable was too big and has been truncated before compilation";
|
||
|
||
/*
|
||
* XXX: With the exception of PCRE_ERROR_MATCHLIMIT we
|
||
* only catch PCRE errors that can happen with our internal
|
||
* version. If Privoxy is linked against a newer
|
||
* PCRE version all bets are off ...
|
||
*/
|
||
default: return "Unknown error. Privoxy out of sync with PCRE?";
|
||
}
|
||
}
|
||
/* error >= 0: No error */
|
||
return "(pcrs:) Everything's just fine. Thanks for asking.";
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_parse_perl_options
|
||
*
|
||
* Description : This function parses a string containing the options to
|
||
* Perl's s/// operator. It returns an integer that is the
|
||
* pcre equivalent of the symbolic optstring.
|
||
* Since pcre doesn't know about Perl's 'g' (global) or pcrs',
|
||
* 'T' (trivial) options but pcrs needs them, the corresponding
|
||
* flags are set if 'g'or 'T' is encountered.
|
||
* Note: The 'T' and 'U' options do not conform to Perl.
|
||
*
|
||
* Parameters :
|
||
* 1 : optstring = string with options in perl syntax
|
||
* 2 : flags = see description
|
||
*
|
||
* Returns : option integer suitable for pcre
|
||
*
|
||
*********************************************************************/
|
||
static int pcrs_parse_perl_options(const char *optstring, int *flags)
|
||
{
|
||
size_t i;
|
||
int rc = 0;
|
||
*flags = 0;
|
||
|
||
if (NULL == optstring) return 0;
|
||
|
||
for (i = 0; i < strlen(optstring); i++)
|
||
{
|
||
switch(optstring[i])
|
||
{
|
||
case 'e': break; /* ToDo ;-) */
|
||
case 'g': *flags |= PCRS_GLOBAL; break;
|
||
case 'i': rc |= PCRE_CASELESS; break;
|
||
case 'm': rc |= PCRE_MULTILINE; break;
|
||
case 'o': break;
|
||
case 's': rc |= PCRE_DOTALL; break;
|
||
case 'x': rc |= PCRE_EXTENDED; break;
|
||
case 'U': rc |= PCRE_UNGREEDY; break;
|
||
case 'T': *flags |= PCRS_TRIVIAL; break;
|
||
default: break;
|
||
}
|
||
}
|
||
return rc;
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_compile_replacement
|
||
*
|
||
* Description : This function takes a Perl-style replacement (2nd argument
|
||
* to the s/// operator and returns a compiled pcrs_substitute,
|
||
* or NULL if memory allocation for the substitute structure
|
||
* fails.
|
||
*
|
||
* Parameters :
|
||
* 1 : replacement = replacement part of s/// operator
|
||
* in perl syntax
|
||
* 2 : trivialflag = Flag that causes backreferences to be
|
||
* ignored.
|
||
* 3 : capturecount = Number of capturing subpatterns in
|
||
* the pattern. Needed for $+ handling.
|
||
* 4 : errptr = pointer to an integer in which error
|
||
* conditions can be returned.
|
||
*
|
||
* Returns : pcrs_substitute data structure, or NULL if an
|
||
* error is encountered. In that case, *errptr has
|
||
* the reason.
|
||
*
|
||
*********************************************************************/
|
||
static pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, int capturecount, int *errptr)
|
||
{
|
||
int i, k, l, quoted;
|
||
size_t length;
|
||
char *text;
|
||
pcrs_substitute *r;
|
||
|
||
i = k = l = quoted = 0;
|
||
|
||
/*
|
||
* Sanity check
|
||
*/
|
||
if (NULL == replacement)
|
||
{
|
||
replacement = "";
|
||
}
|
||
|
||
/*
|
||
* Get memory or fail
|
||
*/
|
||
if (NULL == (r = (pcrs_substitute *)malloc(sizeof(pcrs_substitute))))
|
||
{
|
||
*errptr = PCRS_ERR_NOMEM;
|
||
return NULL;
|
||
}
|
||
memset(r, '\0', sizeof(pcrs_substitute));
|
||
|
||
length = strlen(replacement);
|
||
|
||
if (NULL == (text = (char *)malloc(length + 1)))
|
||
{
|
||
free(r);
|
||
*errptr = PCRS_ERR_NOMEM;
|
||
return NULL;
|
||
}
|
||
memset(text, '\0', length + 1);
|
||
|
||
|
||
/*
|
||
* In trivial mode, just copy the substitute text
|
||
*/
|
||
if (trivialflag)
|
||
{
|
||
text = strncpy(text, replacement, length + 1);
|
||
k = (int)length;
|
||
}
|
||
|
||
/*
|
||
* Else, parse, cut out and record all backreferences
|
||
*/
|
||
else
|
||
{
|
||
while (i < (int)length)
|
||
{
|
||
/* Quoting */
|
||
if (replacement[i] == '\\')
|
||
{
|
||
if (quoted)
|
||
{
|
||
text[k++] = replacement[i++];
|
||
quoted = 0;
|
||
}
|
||
else
|
||
{
|
||
if (replacement[i+1] && strchr("tnrfae0", replacement[i+1]))
|
||
{
|
||
switch (replacement[++i])
|
||
{
|
||
case 't':
|
||
text[k++] = '\t';
|
||
break;
|
||
case 'n':
|
||
text[k++] = '\n';
|
||
break;
|
||
case 'r':
|
||
text[k++] = '\r';
|
||
break;
|
||
case 'f':
|
||
text[k++] = '\f';
|
||
break;
|
||
case 'a':
|
||
text[k++] = 7;
|
||
break;
|
||
case 'e':
|
||
text[k++] = 27;
|
||
break;
|
||
case '0':
|
||
text[k++] = '\0';
|
||
break;
|
||
}
|
||
i++;
|
||
}
|
||
else if (is_hex_sequence(&replacement[i]))
|
||
{
|
||
/*
|
||
* Replace a hex sequence with a single
|
||
* character with the sequence's ascii value.
|
||
* e.g.: '\x7e' => '~'
|
||
*/
|
||
const int ascii_value = xtoi(&replacement[i+2]);
|
||
|
||
assert(ascii_value > 0);
|
||
assert(ascii_value < 256);
|
||
text[k++] = (char)ascii_value;
|
||
i += 4;
|
||
}
|
||
else
|
||
{
|
||
quoted = 1;
|
||
i++;
|
||
}
|
||
}
|
||
continue;
|
||
}
|
||
|
||
/* Backreferences */
|
||
if (replacement[i] == '$' && !quoted && i < (int)(length - 1))
|
||
{
|
||
char *symbol, symbols[] = "'`+&";
|
||
r->block_length[l] = (size_t)(k - r->block_offset[l]);
|
||
|
||
/* Numerical backreferences */
|
||
if (isdigit((int)replacement[i + 1]))
|
||
{
|
||
while (i < (int)length && isdigit((int)replacement[++i]))
|
||
{
|
||
r->backref[l] = r->backref[l] * 10 + replacement[i] - 48;
|
||
}
|
||
if (r->backref[l] > capturecount)
|
||
{
|
||
*errptr = PCRS_WARN_BADREF;
|
||
}
|
||
}
|
||
|
||
/* Symbolic backreferences: */
|
||
else if (NULL != (symbol = strchr(symbols, replacement[i + 1])))
|
||
{
|
||
|
||
if (symbol - symbols == 2) /* $+ */
|
||
{
|
||
r->backref[l] = capturecount;
|
||
}
|
||
else if (symbol - symbols == 3) /* $& */
|
||
{
|
||
r->backref[l] = 0;
|
||
}
|
||
else /* $' or $` */
|
||
{
|
||
r->backref[l] = PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols);
|
||
}
|
||
i += 2;
|
||
}
|
||
|
||
/* Invalid backref -> plain '$' */
|
||
else
|
||
{
|
||
goto plainchar;
|
||
}
|
||
|
||
/* Valid and in range? -> record */
|
||
if (r->backref[l] < PCRS_MAX_SUBMATCHES + 2)
|
||
{
|
||
r->backref_count[r->backref[l]] += 1;
|
||
r->block_offset[++l] = k;
|
||
}
|
||
else
|
||
{
|
||
*errptr = PCRS_WARN_BADREF;
|
||
}
|
||
continue;
|
||
}
|
||
|
||
plainchar:
|
||
/* Plain chars are copied */
|
||
text[k++] = replacement[i++];
|
||
quoted = 0;
|
||
}
|
||
} /* -END- if (!trivialflag) */
|
||
|
||
/*
|
||
* Finish & return
|
||
*/
|
||
r->text = text;
|
||
r->backrefs = l;
|
||
r->length = (size_t)k;
|
||
r->block_length[l] = (size_t)(k - r->block_offset[l]);
|
||
|
||
return r;
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_free_job
|
||
*
|
||
* Description : Frees the memory used by a pcrs_job struct and its
|
||
* dependant structures.
|
||
*
|
||
* Parameters :
|
||
* 1 : job = pointer to the pcrs_job structure to be freed
|
||
*
|
||
* Returns : a pointer to the next job, if there was any, or
|
||
* NULL otherwise.
|
||
*
|
||
*********************************************************************/
|
||
pcrs_job *pcrs_free_job(pcrs_job *job)
|
||
{
|
||
pcrs_job *next;
|
||
|
||
if (job == NULL)
|
||
{
|
||
return NULL;
|
||
}
|
||
else
|
||
{
|
||
next = job->next;
|
||
if (job->pattern != NULL) free(job->pattern);
|
||
if (job->hints != NULL) free(job->hints);
|
||
if (job->substitute != NULL)
|
||
{
|
||
if (job->substitute->text != NULL) free(job->substitute->text);
|
||
free(job->substitute);
|
||
}
|
||
free(job);
|
||
}
|
||
return next;
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_free_joblist
|
||
*
|
||
* Description : Iterates through a chained list of pcrs_job's and
|
||
* frees them using pcrs_free_job.
|
||
*
|
||
* Parameters :
|
||
* 1 : joblist = pointer to the first pcrs_job structure to
|
||
* be freed
|
||
*
|
||
* Returns : N/A
|
||
*
|
||
*********************************************************************/
|
||
void pcrs_free_joblist(pcrs_job *joblist)
|
||
{
|
||
while ( NULL != (joblist = pcrs_free_job(joblist)) ) {};
|
||
|
||
return;
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_compile_command
|
||
*
|
||
* Description : Parses a string with a Perl-style s/// command,
|
||
* calls pcrs_compile, and returns a corresponding
|
||
* pcrs_job, or NULL if parsing or compiling the job
|
||
* fails.
|
||
*
|
||
* Parameters :
|
||
* 1 : command = string with perl-style s/// command
|
||
* 2 : errptr = pointer to an integer in which error
|
||
* conditions can be returned.
|
||
*
|
||
* Returns : a corresponding pcrs_job data structure, or NULL
|
||
* if an error was encountered. In that case, *errptr
|
||
* has the reason.
|
||
*
|
||
*********************************************************************/
|
||
pcrs_job *pcrs_compile_command(const char *command, int *errptr)
|
||
{
|
||
int i, k, l, quoted = FALSE;
|
||
size_t limit;
|
||
char delimiter;
|
||
char *tokens[4];
|
||
pcrs_job *newjob;
|
||
|
||
i = k = l = 0;
|
||
|
||
/*
|
||
* Tokenize the perl command
|
||
*/
|
||
limit = strlen(command);
|
||
if (limit < 4)
|
||
{
|
||
*errptr = PCRS_ERR_CMDSYNTAX;
|
||
return NULL;
|
||
}
|
||
else
|
||
{
|
||
delimiter = command[1];
|
||
}
|
||
|
||
tokens[l] = (char *) malloc(limit + 1);
|
||
|
||
for (i = 0; i <= (int)limit; i++)
|
||
{
|
||
|
||
if (command[i] == delimiter && !quoted)
|
||
{
|
||
if (l == 3)
|
||
{
|
||
l = -1;
|
||
break;
|
||
}
|
||
tokens[0][k++] = '\0';
|
||
tokens[++l] = tokens[0] + k;
|
||
continue;
|
||
}
|
||
|
||
else if (command[i] == '\\' && !quoted)
|
||
{
|
||
quoted = TRUE;
|
||
if (command[i+1] == delimiter) continue;
|
||
}
|
||
else
|
||
{
|
||
quoted = FALSE;
|
||
}
|
||
tokens[0][k++] = command[i];
|
||
}
|
||
|
||
/*
|
||
* Syntax error ?
|
||
*/
|
||
if (l != 3)
|
||
{
|
||
*errptr = PCRS_ERR_CMDSYNTAX;
|
||
free(tokens[0]);
|
||
return NULL;
|
||
}
|
||
|
||
newjob = pcrs_compile(tokens[1], tokens[2], tokens[3], errptr);
|
||
free(tokens[0]);
|
||
return newjob;
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_compile
|
||
*
|
||
* Description : Takes the three arguments to a perl s/// command
|
||
* and compiles a pcrs_job structure from them.
|
||
*
|
||
* Parameters :
|
||
* 1 : pattern = string with perl-style pattern
|
||
* 2 : substitute = string with perl-style substitute
|
||
* 3 : options = string with perl-style options
|
||
* 4 : errptr = pointer to an integer in which error
|
||
* conditions can be returned.
|
||
*
|
||
* Returns : a corresponding pcrs_job data structure, or NULL
|
||
* if an error was encountered. In that case, *errptr
|
||
* has the reason.
|
||
*
|
||
*********************************************************************/
|
||
pcrs_job *pcrs_compile(const char *pattern, const char *substitute, const char *options, int *errptr)
|
||
{
|
||
pcrs_job *newjob;
|
||
int flags;
|
||
int capturecount;
|
||
const char *error;
|
||
|
||
*errptr = 0;
|
||
|
||
/*
|
||
* Handle NULL arguments
|
||
*/
|
||
if (pattern == NULL) pattern = "";
|
||
if (substitute == NULL) substitute = "";
|
||
|
||
|
||
/*
|
||
* Get and init memory
|
||
*/
|
||
if (NULL == (newjob = (pcrs_job *)malloc(sizeof(pcrs_job))))
|
||
{
|
||
*errptr = PCRS_ERR_NOMEM;
|
||
return NULL;
|
||
}
|
||
memset(newjob, '\0', sizeof(pcrs_job));
|
||
|
||
|
||
/*
|
||
* Evaluate the options
|
||
*/
|
||
newjob->options = pcrs_parse_perl_options(options, &flags);
|
||
newjob->flags = flags;
|
||
|
||
|
||
/*
|
||
* Compile the pattern
|
||
*/
|
||
newjob->pattern = pcre_compile(pattern, newjob->options, &error, errptr, NULL);
|
||
if (newjob->pattern == NULL)
|
||
{
|
||
pcrs_free_job(newjob);
|
||
return NULL;
|
||
}
|
||
|
||
|
||
/*
|
||
* Generate hints. This has little overhead, since the
|
||
* hints will be NULL for a boring pattern anyway.
|
||
*/
|
||
newjob->hints = pcre_study(newjob->pattern, 0, &error);
|
||
if (error != NULL)
|
||
{
|
||
*errptr = PCRS_ERR_STUDY;
|
||
pcrs_free_job(newjob);
|
||
return NULL;
|
||
}
|
||
|
||
|
||
/*
|
||
* Determine the number of capturing subpatterns.
|
||
* This is needed for handling $+ in the substitute.
|
||
*/
|
||
if (0 > (*errptr = pcre_fullinfo(newjob->pattern, newjob->hints, PCRE_INFO_CAPTURECOUNT, &capturecount)))
|
||
{
|
||
pcrs_free_job(newjob);
|
||
return NULL;
|
||
}
|
||
|
||
|
||
/*
|
||
* Compile the substitute
|
||
*/
|
||
if (NULL == (newjob->substitute = pcrs_compile_replacement(substitute, newjob->flags & PCRS_TRIVIAL, capturecount, errptr)))
|
||
{
|
||
pcrs_free_job(newjob);
|
||
return NULL;
|
||
}
|
||
|
||
return newjob;
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_execute_list
|
||
*
|
||
* Description : This is a multiple job wrapper for pcrs_execute().
|
||
* Apply the regular substitutions defined by the jobs in
|
||
* the joblist to the subject.
|
||
* The subject itself is left untouched, memory for the result
|
||
* is malloc()ed and it is the caller's responsibility to free
|
||
* the result when it's no longer needed.
|
||
*
|
||
* Note: For convenient string handling, a null byte is
|
||
* appended to the result. It does not count towards the
|
||
* result_length, though.
|
||
*
|
||
*
|
||
* Parameters :
|
||
* 1 : joblist = the chained list of pcrs_jobs to be executed
|
||
* 2 : subject = the subject string
|
||
* 3 : subject_length = the subject's length
|
||
* 4 : result = char** for returning the result
|
||
* 5 : result_length = size_t* for returning the result's length
|
||
*
|
||
* Returns : On success, the number of substitutions that were made.
|
||
* May be > 1 if job->flags contained PCRS_GLOBAL
|
||
* On failure, the (negative) pcre error code describing the
|
||
* failure, which may be translated to text using pcrs_strerror().
|
||
*
|
||
*********************************************************************/
|
||
int pcrs_execute_list(pcrs_job *joblist, char *subject, size_t subject_length, char **result, size_t *result_length)
|
||
{
|
||
pcrs_job *job;
|
||
char *old, *new = NULL;
|
||
int hits, total_hits;
|
||
|
||
old = subject;
|
||
*result_length = subject_length;
|
||
hits = total_hits = 0;
|
||
|
||
for (job = joblist; job != NULL; job = job->next)
|
||
{
|
||
hits = pcrs_execute(job, old, *result_length, &new, result_length);
|
||
|
||
if (old != subject) free(old);
|
||
|
||
if (hits < 0)
|
||
{
|
||
return(hits);
|
||
}
|
||
else
|
||
{
|
||
total_hits += hits;
|
||
old = new;
|
||
}
|
||
}
|
||
|
||
*result = new;
|
||
return(total_hits);
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_execute
|
||
*
|
||
* Description : Apply the regular substitution defined by the job to the
|
||
* subject.
|
||
* The subject itself is left untouched, memory for the result
|
||
* is malloc()ed and it is the caller's responsibility to free
|
||
* the result when it's no longer needed.
|
||
*
|
||
* Note: For convenient string handling, a null byte is
|
||
* appended to the result. It does not count towards the
|
||
* result_length, though.
|
||
*
|
||
* Parameters :
|
||
* 1 : job = the pcrs_job to be executed
|
||
* 2 : subject = the subject (== original) string
|
||
* 3 : subject_length = the subject's length
|
||
* 4 : result = char** for returning the result
|
||
* 5 : result_length = size_t* for returning the result's length
|
||
*
|
||
* Returns : On success, the number of substitutions that were made.
|
||
* May be > 1 if job->flags contained PCRS_GLOBAL
|
||
* On failure, the (negative) pcre error code describing the
|
||
* failure, which may be translated to text using pcrs_strerror().
|
||
*
|
||
*********************************************************************/
|
||
int pcrs_execute(pcrs_job *job, const char *subject, size_t subject_length, char **result, size_t *result_length)
|
||
{
|
||
int offsets[3 * PCRS_MAX_SUBMATCHES],
|
||
offset,
|
||
i, k,
|
||
matches_found,
|
||
submatches,
|
||
max_matches = PCRS_MAX_MATCH_INIT;
|
||
size_t newsize;
|
||
pcrs_match *matches, *dummy;
|
||
char *result_offset;
|
||
|
||
offset = i = k = 0;
|
||
|
||
/*
|
||
* Sanity check & memory allocation
|
||
*/
|
||
if (job == NULL || job->pattern == NULL || job->substitute == NULL || NULL == subject)
|
||
{
|
||
*result = NULL;
|
||
return(PCRS_ERR_BADJOB);
|
||
}
|
||
|
||
if (NULL == (matches = (pcrs_match *)malloc((size_t)max_matches * sizeof(pcrs_match))))
|
||
{
|
||
*result = NULL;
|
||
return(PCRS_ERR_NOMEM);
|
||
}
|
||
memset(matches, '\0', (size_t)max_matches * sizeof(pcrs_match));
|
||
|
||
|
||
/*
|
||
* Find the pattern and calculate the space
|
||
* requirements for the result
|
||
*/
|
||
newsize = subject_length;
|
||
|
||
while ((submatches = pcre_exec(job->pattern, job->hints, subject, (int)subject_length, offset, 0, offsets, 3 * PCRS_MAX_SUBMATCHES)) > 0)
|
||
{
|
||
job->flags |= PCRS_SUCCESS;
|
||
matches[i].submatches = submatches;
|
||
|
||
for (k = 0; k < submatches; k++)
|
||
{
|
||
matches[i].submatch_offset[k] = offsets[2 * k];
|
||
|
||
/* Note: Non-found optional submatches have length -1-(-1)==0 */
|
||
matches[i].submatch_length[k] = (size_t)(offsets[2 * k + 1] - offsets[2 * k]);
|
||
|
||
/* reserve mem for each submatch as often as it is ref'd */
|
||
newsize += matches[i].submatch_length[k] * (size_t)job->substitute->backref_count[k];
|
||
}
|
||
/* plus replacement text size minus match text size */
|
||
newsize += job->substitute->length - matches[i].submatch_length[0];
|
||
|
||
/* chunk before match */
|
||
matches[i].submatch_offset[PCRS_MAX_SUBMATCHES] = 0;
|
||
matches[i].submatch_length[PCRS_MAX_SUBMATCHES] = (size_t)offsets[0];
|
||
newsize += (size_t)offsets[0] * (size_t)job->substitute->backref_count[PCRS_MAX_SUBMATCHES];
|
||
|
||
/* chunk after match */
|
||
matches[i].submatch_offset[PCRS_MAX_SUBMATCHES + 1] = offsets[1];
|
||
matches[i].submatch_length[PCRS_MAX_SUBMATCHES + 1] = subject_length - (size_t)offsets[1] - 1;
|
||
newsize += (subject_length - (size_t)offsets[1]) * (size_t)job->substitute->backref_count[PCRS_MAX_SUBMATCHES + 1];
|
||
|
||
/* Storage for matches exhausted? -> Extend! */
|
||
if (++i >= max_matches)
|
||
{
|
||
max_matches = (int)(max_matches * PCRS_MAX_MATCH_GROW);
|
||
if (NULL == (dummy = (pcrs_match *)realloc(matches, (size_t)max_matches * sizeof(pcrs_match))))
|
||
{
|
||
free(matches);
|
||
*result = NULL;
|
||
return(PCRS_ERR_NOMEM);
|
||
}
|
||
matches = dummy;
|
||
}
|
||
|
||
/* Non-global search or limit reached? */
|
||
if (!(job->flags & PCRS_GLOBAL)) break;
|
||
|
||
/* Don't loop on empty matches */
|
||
if (offsets[1] == offset)
|
||
if ((size_t)offset < subject_length)
|
||
offset++;
|
||
else
|
||
break;
|
||
/* Go find the next one */
|
||
else
|
||
offset = offsets[1];
|
||
}
|
||
/* Pass pcre error through if (bad) failiure */
|
||
if (submatches < PCRE_ERROR_NOMATCH)
|
||
{
|
||
free(matches);
|
||
return submatches;
|
||
}
|
||
matches_found = i;
|
||
|
||
|
||
/*
|
||
* Get memory for the result (must be freed by caller!)
|
||
* and append terminating null byte.
|
||
*/
|
||
if ((*result = (char *)malloc(newsize + 1)) == NULL)
|
||
{
|
||
free(matches);
|
||
return PCRS_ERR_NOMEM;
|
||
}
|
||
else
|
||
{
|
||
(*result)[newsize] = '\0';
|
||
}
|
||
|
||
|
||
/*
|
||
* Replace
|
||
*/
|
||
offset = 0;
|
||
result_offset = *result;
|
||
|
||
for (i = 0; i < matches_found; i++)
|
||
{
|
||
/* copy the chunk preceding the match */
|
||
memcpy(result_offset, subject + offset, (size_t)(matches[i].submatch_offset[0] - offset));
|
||
result_offset += matches[i].submatch_offset[0] - offset;
|
||
|
||
/* For every segment of the substitute.. */
|
||
for (k = 0; k <= job->substitute->backrefs; k++)
|
||
{
|
||
/* ...copy its text.. */
|
||
memcpy(result_offset, job->substitute->text + job->substitute->block_offset[k], job->substitute->block_length[k]);
|
||
result_offset += job->substitute->block_length[k];
|
||
|
||
/* ..plus, if it's not the last chunk, i.e.: There *is* a backref.. */
|
||
if (k != job->substitute->backrefs
|
||
/* ..in legal range.. */
|
||
&& job->substitute->backref[k] < PCRS_MAX_SUBMATCHES + 2
|
||
/* ..and referencing a real submatch.. */
|
||
&& job->substitute->backref[k] < matches[i].submatches
|
||
/* ..that is nonempty.. */
|
||
&& matches[i].submatch_length[job->substitute->backref[k]] > 0)
|
||
{
|
||
/* ..copy the submatch that is ref'd. */
|
||
memcpy(
|
||
result_offset,
|
||
subject + matches[i].submatch_offset[job->substitute->backref[k]],
|
||
matches[i].submatch_length[job->substitute->backref[k]]
|
||
);
|
||
result_offset += matches[i].submatch_length[job->substitute->backref[k]];
|
||
}
|
||
}
|
||
offset = matches[i].submatch_offset[0] + (int)matches[i].submatch_length[0];
|
||
}
|
||
|
||
/* Copy the rest. */
|
||
memcpy(result_offset, subject + offset, subject_length - (size_t)offset);
|
||
|
||
*result_length = newsize;
|
||
free(matches);
|
||
return matches_found;
|
||
|
||
}
|
||
|
||
|
||
#define is_hex_digit(x) ((x) && strchr("0123456789ABCDEF", toupper(x)))
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : is_hex_sequence
|
||
*
|
||
* Description : Checks the first four characters of a string
|
||
* and decides if they are a valid hex sequence
|
||
* (like '\x40').
|
||
*
|
||
* Parameters :
|
||
* 1 : sequence = The string to check
|
||
*
|
||
* Returns : Non-zero if it's valid sequence, or
|
||
* Zero if it isn't.
|
||
*
|
||
*********************************************************************/
|
||
static int is_hex_sequence(const char *sequence)
|
||
{
|
||
return (sequence[0] == '\\' &&
|
||
sequence[1] == 'x' &&
|
||
is_hex_digit(sequence[2]) &&
|
||
is_hex_digit(sequence[3]));
|
||
}
|
||
|
||
|
||
/*
|
||
* Functions below this line are only part of the pcrs version
|
||
* included in Privoxy. If you use any of them you should not
|
||
* try to dynamically link against external pcrs versions.
|
||
*/
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_job_is_dynamic
|
||
*
|
||
* Description : Checks if a job has the "D" (dynamic) option set.
|
||
*
|
||
* Parameters :
|
||
* 1 : job = The job to check
|
||
*
|
||
* Returns : TRUE if the job is indeed dynamic, otherwise
|
||
* FALSE
|
||
*
|
||
*********************************************************************/
|
||
int pcrs_job_is_dynamic (char *job)
|
||
{
|
||
const char delimiter = job[1];
|
||
const size_t length = strlen(job);
|
||
char *option;
|
||
|
||
if (length < 5)
|
||
{
|
||
/*
|
||
* The shortest valid (but useless)
|
||
* dynamic pattern is "s@@@D"
|
||
*/
|
||
return FALSE;
|
||
}
|
||
|
||
/*
|
||
* Everything between the last character
|
||
* and the last delimiter is an option ...
|
||
*/
|
||
for (option = job + length; *option != delimiter; option--)
|
||
{
|
||
if (*option == 'D')
|
||
{
|
||
/*
|
||
* ... and if said option is 'D' the job is dynamic.
|
||
*/
|
||
return TRUE;
|
||
}
|
||
}
|
||
return FALSE;
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_get_delimiter
|
||
*
|
||
* Description : Tries to find a character that is safe to
|
||
* be used as a pcrs delimiter for a certain string.
|
||
*
|
||
* Parameters :
|
||
* 1 : string = The string to search in
|
||
*
|
||
* Returns : A safe delimiter if one was found, otherwise '\0'.
|
||
*
|
||
*********************************************************************/
|
||
char pcrs_get_delimiter(const char *string)
|
||
{
|
||
/*
|
||
* Some characters that are unlikely to
|
||
* be part of pcrs replacement strings.
|
||
*/
|
||
char delimiters[] = "><<3C>#+*~%^<5E>-:;<3B>!@";
|
||
char *d = delimiters;
|
||
|
||
/* Take the first delimiter that isn't part of the string */
|
||
while (*d && NULL != strchr(string, *d))
|
||
{
|
||
d++;
|
||
}
|
||
return *d;
|
||
|
||
}
|
||
|
||
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_execute_single_command
|
||
*
|
||
* Description : Apply single pcrs command to the subject.
|
||
* The subject itself is left untouched, memory for the result
|
||
* is malloc()ed and it is the caller's responsibility to free
|
||
* the result when it's no longer needed.
|
||
*
|
||
* Parameters :
|
||
* 1 : subject = the subject (== original) string
|
||
* 2 : pcrs_command = the pcrs command as string (s@foo@bar@)
|
||
* 3 : hits = int* for returning the number of modifications
|
||
*
|
||
* Returns : NULL in case of errors, otherwise the
|
||
* result of the pcrs command.
|
||
*
|
||
*********************************************************************/
|
||
char *pcrs_execute_single_command(const char *subject, const char *pcrs_command, int *hits)
|
||
{
|
||
size_t size;
|
||
char *result = NULL;
|
||
pcrs_job *job;
|
||
|
||
assert(subject);
|
||
assert(pcrs_command);
|
||
|
||
*hits = 0;
|
||
size = strlen(subject);
|
||
|
||
job = pcrs_compile_command(pcrs_command, hits);
|
||
if (NULL != job)
|
||
{
|
||
*hits = pcrs_execute(job, subject, size, &result, &size);
|
||
if (*hits < 0)
|
||
{
|
||
freez(result);
|
||
}
|
||
pcrs_free_job(job);
|
||
}
|
||
return result;
|
||
|
||
}
|
||
|
||
|
||
static const char warning[] = "... [too long, truncated]";
|
||
/*********************************************************************
|
||
*
|
||
* Function : pcrs_compile_dynamic_command
|
||
*
|
||
* Description : Takes a dynamic pcrs command, fills in the
|
||
* values of the variables and compiles it.
|
||
*
|
||
* Parameters :
|
||
* 1 : csp = Current client state (buffers, headers, etc...)
|
||
* 2 : pcrs_command = The dynamic pcrs command to compile
|
||
* 3 : v = NULL terminated array of variables and their values.
|
||
* 4 : error = pcrs error code
|
||
*
|
||
* Returns : NULL in case of hard errors, otherwise the
|
||
* compiled pcrs job.
|
||
*
|
||
*********************************************************************/
|
||
pcrs_job *pcrs_compile_dynamic_command(char *pcrs_command, const struct pcrs_variable v[], int *error)
|
||
{
|
||
char buf[PCRS_BUFFER_SIZE];
|
||
const char *original_pcrs_command = pcrs_command;
|
||
char *pcrs_command_tmp = NULL;
|
||
pcrs_job *job = NULL;
|
||
int truncation = 0;
|
||
char d;
|
||
int ret;
|
||
|
||
while ((NULL != v->name) && (NULL != pcrs_command))
|
||
{
|
||
assert(NULL != v->value);
|
||
|
||
if (NULL == strstr(pcrs_command, v->name))
|
||
{
|
||
/*
|
||
* Skip the substitution if the variable
|
||
* name isn't part of the pattern.
|
||
*/
|
||
v++;
|
||
continue;
|
||
}
|
||
|
||
/* Use pcrs to replace the variable with its value. */
|
||
d = pcrs_get_delimiter(v->value);
|
||
if ('\0' == d)
|
||
{
|
||
/* No proper delimiter found */
|
||
*error = PCRS_ERR_CMDSYNTAX;
|
||
return NULL;
|
||
}
|
||
|
||
/*
|
||
* Variable names are supposed to contain alpha
|
||
* numerical characters plus '_' only.
|
||
*/
|
||
assert(NULL == strchr(v->name, d));
|
||
|
||
ret = snprintf(buf, sizeof(buf), "s%c\\$%s%c%s%cgT", d, v->name, d, v->value, d);
|
||
assert(ret >= 0);
|
||
if (ret >= sizeof(buf))
|
||
{
|
||
/*
|
||
* Value didn't completely fit into buffer,
|
||
* overwrite the end of the substitution text
|
||
* with a truncation message and close the pattern
|
||
* properly.
|
||
*/
|
||
const size_t trailer_size = sizeof(warning) + 3; /* 3 for d + "gT" */
|
||
char *trailer_start = buf + sizeof(buf) - trailer_size;
|
||
|
||
ret = snprintf(trailer_start, trailer_size, "%s%cgT", warning, d);
|
||
assert(ret == trailer_size - 1);
|
||
assert(sizeof(buf) == strlen(buf) + 1);
|
||
truncation = 1;
|
||
}
|
||
|
||
pcrs_command_tmp = pcrs_execute_single_command(pcrs_command, buf, error);
|
||
if (NULL == pcrs_command_tmp)
|
||
{
|
||
return NULL;
|
||
}
|
||
|
||
if (pcrs_command != original_pcrs_command)
|
||
{
|
||
freez(pcrs_command);
|
||
}
|
||
pcrs_command = pcrs_command_tmp;
|
||
|
||
v++;
|
||
}
|
||
|
||
job = pcrs_compile_command(pcrs_command, error);
|
||
if (pcrs_command != original_pcrs_command)
|
||
{
|
||
freez(pcrs_command);
|
||
}
|
||
|
||
if (truncation)
|
||
{
|
||
*error = PCRS_WARN_TRUNCATION;
|
||
}
|
||
|
||
return job;
|
||
|
||
}
|
||
|
||
|
||
/*
|
||
Local Variables:
|
||
tab-width: 3
|
||
end:
|
||
*/
|