X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=pcrs.c;h=83ea4be7d9281977efd5d56080b2b8eb663b5b86;hp=0cff5f8307d8ddd90b580930ef89b6f8a7705256;hb=c350eb3c7c8ce5484853795b7cfe17a5f57be89c;hpb=2d3a5943ff38550fd73e6b5b29ac561b2a9be2cd diff --git a/pcrs.c b/pcrs.c index 0cff5f83..83ea4be7 100644 --- a/pcrs.c +++ b/pcrs.c @@ -1,95 +1,110 @@ -const char pcrs_rcs[] = "$Id: pcrs.c,v 1.3 2001/05/25 11:03:55 oes Exp $"; +const char pcrs_rcs[] = "$Id: pcrs.c,v 1.14 2001/09/09 21:41:57 oes Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/pcrs.c,v $ * - * Purpose : This is the alpha release of libpcrs. It is only published - * at this early stage of development, because it is - * needed for a new feature in JunkBuster. + * Purpose : pcrs is a supplement to the pcre library by Philip Hazel + * and adds Perl-style substitution. That + * is, it mimics Perl's 's' operator. See pcrs(3) for details. * - * While no inconsistencies, memory leaks or functional bugs - * are known at this time, there *could* be plenty ;-). Also, - * Many pcre-specific options are not yet supported, and - * error handling needs improvement. * - * pcrs is a supplement to the brilliant pcre library by Philip - * Hazel (ph10@cam.ac.uk) and adds Perl-style substitution. That - * is, it mimics Perl's 's' operator. - * - * Currently, there's no documentation besides comments and the - * source itself ;-) - * - * Copyright : Written and Copyright (C) 2000 by Andreas Oesterhelt + * Copyright : Written and Copyright (C) 2000, 2001 by Andreas S. Oesterhelt * * * 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. + * 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 GNU General Public - * License for more details. + * PARTICULAR PURPOSE. See the license for more details. * - * The GNU General Public License should be included with - * this file. If not, you can view it at - * http://www.gnu.org/copyleft/gpl.html + * 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 1.14 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 + * Fixed bug: Empty substitutes now detected + * * Revision 1.3 2001/05/25 11:03:55 oes * Added sanity check for NULL jobs to pcrs_exec_substitution * * Revision 1.2 2001/05/22 18:46:04 oes * - * - Enabled filtering banners by size rather than URL - * by adding patterns that replace all standard banner - * sizes with the "Junkbuster" gif to the re_filterfile - * - * - Enabled filtering WebBugs by providing a pattern - * which kills all 1x1 images - * - * - Added support for PCRE_UNGREEDY behaviour to pcrs, + * Added support for PCRE_UNGREEDY behaviour to pcrs, * 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 (!). * - * - Added a new interceptor ijb-send-banner, which - * sends back the "Junkbuster" gif. Without imagelist or - * MSIE detection support, or if tinygif = 1, or the - * URL isn't recognized as an imageurl, a lame HTML - * explanation is sent instead. - * - * - Added new feature, which permits blocking remote - * script redirects and firing back a local redirect - * to the browser. - * The feature is conditionally compiled, i.e. it - * can be disabled with --disable-fast-redirects, - * plus it must be activated by a "fast-redirects" - * line in the config file, has its own log level - * and of course wants to be displayed by show-proxy-args - * Note: Boy, all the #ifdefs in 1001 locations and - * all the fumbling with configure.in and acconfig.h - * were *way* more work than the feature itself :-( - * - * - Because a generic redirect template was needed for - * this, tinygif = 3 now uses the same. - * - * - Moved GIFs, and other static HTTP response templates - * to project.h - * - * - Some minor fixes - * - * - Removed some >400 CRs again (Jon, you really worked - * a lot! ;-) - * * Revision 1.1.1.1 2001/05/15 13:59:02 oes * Initial import of version 2.9.3 source tree * @@ -99,98 +114,101 @@ const char pcrs_rcs[] = "$Id: pcrs.c,v 1.3 2001/05/25 11:03:55 oes Exp $"; #include #include +#include + #include "pcrs.h" -const char pcrs_h_rcs[] = PCRS_H_VERSION; +const char pcrs_h_rcs[] = PCRS_H_VERSION; /********************************************************************* * - * Function : my_strsep - * - * Description : Convenience function. It acts like strsep, except that - * it respects quoting of the delimiter character with the - * quote character. (And, of course, quoting the quote char - * with itself.) Called from `pcrs_make_job'. + * Function : pcrs_strerror * + * Description : Return a string describing a given error code. + * * Parameters : - * 1 : token = current token - * 2 : text = string to tokenize - * 3 : delimiter = single character deliminter - * 4 : quote_char = character to cause quoting + * 1 : error = the error code * - * Returns : -1 => failure, else the length of the token found. - * In the latter case, *text is the token's start. + * Returns : char * to the descriptive string * *********************************************************************/ -int my_strsep(char *token, char **text, char delimiter, char quote_char) +const char *pcrs_strerror(const int error) { - int i, k=0, limit, quoted = FALSE; - - limit = strlen(*text); - if ( 0 == limit ) - { - return -1; - } - - token[0] = '\0'; - - for (i=0; i < limit; i++) + if (error < 0) { - if (text[0][i] == delimiter && !quoted) + switch (error) { - *text += 1; - break; + /* 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"; + + /* PCRS errors: */ + case PCRS_ERR_NOMEM: return "(pcrs:) No memory"; + case PCRS_ERR_CMDSYNTAX: return "(pcrs:) Syntax error while parsing command"; + 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"; + + /* What's that? */ + default: return "Unknown error"; } - else if (text[0][i] == quote_char && !quoted && i+1 < limit && text[0][i+1] == delimiter) - { - quoted = TRUE; - continue; - } - token[k++] = text[0][i]; - quoted = FALSE; } - token[k] = '\0'; - *text += i; - return k; + /* error >= 0: No error */ + return "(pcrs:) Everything's just fine. Thanks for asking."; } /********************************************************************* * - * Function : pcrs_compile_perl_options + * 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) option, - * but pcrs needs it, the globalflag integer is set if 'g' - * is encountered. - * + * 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 : globalflag = see description + * 2 : flags = see description * * Returns : option integer suitable for pcre * *********************************************************************/ -int pcrs_compile_perl_options(char *optstring, int *globalflag) +int pcrs_parse_perl_options(const char *optstring, int *flags) { - int i, rc = 0; - *globalflag = 0; + 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; - case 'g': *globalflag = 1; break; + 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; - default: break; + case 'T': *flags |= PCRS_TRIVIAL; break; + default: break; } } return rc; @@ -210,7 +228,11 @@ int pcrs_compile_perl_options(char *optstring, int *globalflag) * Parameters : * 1 : replacement = replacement part of s/// operator * in perl syntax - * 2 : errptr = pointer to an integer in which error + * 2 : trivialflag = Flag that causes backreferences to be + * ignored. + * 3 : capturecount = Number of capturing subpatterns in + * the pattern. Needed for $+ handling. + * 4 : errptr = pointer to an integer in which error * conditions can be returned. * * Returns : pcrs_substitute data structure, or NULL if an @@ -218,82 +240,177 @@ int pcrs_compile_perl_options(char *optstring, int *globalflag) * the reason. * *********************************************************************/ -pcrs_substitute *pcrs_compile_replacement(char *replacement, int *errptr) +pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, int capturecount, int *errptr) { - int length, i, k = 0, l = 0, quoted = 0, idx; - char *text, *num_ptr, *numbers = "0123456789"; + int length, i, k, l, quoted; + char *text; pcrs_substitute *r; - r = (pcrs_substitute *)malloc(sizeof(pcrs_substitute)); - if (r == NULL) return NULL; - memset(r, '\0', sizeof(pcrs_substitute)); + i = k = l = quoted = 0; - text = strdup(replacement); /* must be free()d by caller */ - if (text == NULL) + /* + * Sanity check + */ + if (NULL == replacement) + { + replacement = ""; + } + + /* + * Get memory or fail + */ + if (NULL == (r = (pcrs_substitute *)malloc(sizeof(pcrs_substitute)))) { *errptr = PCRS_ERR_NOMEM; - free(r); return NULL; } + memset(r, '\0', sizeof(pcrs_substitute)); length = strlen(replacement); - for (i=0; i < length; i++) + if (NULL == (text = (char *)malloc(length + 1))) { - /* Backslash treatment */ - if (replacement[i] == '\\') - { - if (quoted) - { - text[k++] = replacement[i]; - quoted = 0; - } - else - { - quoted = 1; - } - continue; - } + free(r); + *errptr = PCRS_ERR_NOMEM; + return NULL; + } + memset(text, '\0', length + 1); + + + /* + * In trivial mode, just copy the substitute text + */ + if (trivialflag) + { + text = strncpy(text, replacement, length + 1); + k = length; + } - /* Dollar treatment */ - if (replacement[i] == '$' && !quoted && i < length - 1) + /* + * Else, parse, cut out and record all backreferences + */ + else + { + while(i < length) { - if (strchr("0123456789&", replacement[i + 1]) == NULL) + /* Quoting */ + if (replacement[i] == '\\') { - text[k++] = 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++] = '\a'; + break; + case 'e': + text[k++] = 27; + break; + case '0': + text[k++] = '\0'; + break; + } + i++; + } + else + { + quoted = 1; + i++; + } + } + continue; } - else + + /* Backreferences */ + if (replacement[i] == '$' && !quoted && i < length - 1) { + char *symbol, symbols[] = "'`+&"; r->block_length[l] = k - r->block_offset[l]; - r->backref[l] = 0; - if (replacement[i + 1] != '&') + + /* Numerical backreferences */ + if (isdigit((int) replacement[i + 1])) + { + while (i < 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]))) { - while ((num_ptr = strchr(numbers, replacement[++i])) != NULL && i < length) + + if (symbol - symbols == 2) /* $+ */ + { + r->backref[l] = capturecount; + } + else if (symbol - symbols == 3) /* $& */ + { + r->backref[l] = 0; + } + else /* $' or $` */ { - idx = num_ptr - numbers; - r->backref[l] = r->backref[l] * 10 + idx; + r->backref[l] = PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols); } - i--; + i += 2; } + + /* Invalid backref -> plain '$' */ else - i++; - if (r->backref[l] < PCRS_MAX_SUBMATCHES) + { + goto plainchar; + } + + /* Valid and in range? -> record */ + if (r->backref[l] < PCRS_MAX_SUBMATCHES + 2) + { r->backref_count[r->backref[l]] += 1; - l++; - r->block_offset[l] = k; + r->block_offset[++l] = k; + } + else + { + *errptr = PCRS_WARN_BADREF; + } + continue; } - continue; + +plainchar: + /* Plain chars are copied */ + text[k++] = replacement[i++]; + quoted = 0; } + } /* -END- if (!trivialflag) */ - /* Plain char treatment */ - text[k++] = replacement[i]; - quoted = 0; - } - - text[k] = '\0'; + /* + * Finish & return + */ r->text = text; r->backrefs = l; r->block_length[l] = k - r->block_offset[l]; + return r; } @@ -304,14 +421,13 @@ pcrs_substitute *pcrs_compile_replacement(char *replacement, int *errptr) * Function : pcrs_free_job * * Description : Frees the memory used by a pcrs_job struct and its - * dependant structures. Returns a pointer to the next - * job, if there was any, or NULL otherwise. + * 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. + * Returns : a pointer to the next job, if there was any, or + * NULL otherwise. * *********************************************************************/ pcrs_job *pcrs_free_job(pcrs_job *job) @@ -341,12 +457,35 @@ pcrs_job *pcrs_free_job(pcrs_job *job) /********************************************************************* * - * Function : pcrs_make_job + * Function : pcrs_free_joblist * - * Description : Main entry point. Takes a string with a Perl-style - * s/// command and returns a corresponding pcrs_job, - * or NULL if compiling the job fails at any stage. - * Diagnostics could obviously be improved. + * 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 @@ -358,91 +497,138 @@ pcrs_job *pcrs_free_job(pcrs_job *job) * has the reason. * *********************************************************************/ -pcrs_job *pcrs_make_job(char *command, int *errptr) +pcrs_job *pcrs_compile_command(const char *command, int *errptr) { - char *dummy, *token, delimiter; - const char *error; - int i = 0, globalflag; + int i, k, l, limit, quoted = FALSE; + char delimiter; + char *tokens[4]; pcrs_job *newjob; - - /* Get and init memory */ - if ((newjob = (pcrs_job *)malloc(sizeof(pcrs_job))) == NULL) + + i = k = l = 0; + + /* + * Tokenize the perl command + */ + limit = strlen(command); + if (limit < 4) { - *errptr = PCRS_ERR_NOMEM; + *errptr = PCRS_ERR_CMDSYNTAX; return NULL; } - memset(newjob, '\0', sizeof(pcrs_job)); - - /* Command too short? */ - if (strlen(command) < 4) + else { - *errptr = PCRS_ERR_CMDSYNTAX; - pcrs_free_job(newjob); - return NULL; + delimiter = command[1]; } - /* Split command into tokens and handle them */ - delimiter = command[1]; - token = (char *)malloc(strlen(command)); /* current token */ - dummy = (char *)malloc(strlen(command)); /* must store pattern, since we can't */ - /* use it until the options are known */ - while (my_strsep(token, &command, delimiter, '\\') >= 0) + tokens[l] = (char *) malloc(limit + 1); + + for (i=0; i <= limit; i++) { - switch (i) + + if (command[i] == delimiter && !quoted) { - /* We don't care about the command and assume 's' */ - case 0: + 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]; + } - /* The pattern */ - case 1: - strcpy(dummy, token); - break; + /* + * 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; + +} - /* The substitute */ - case 2: - if ((newjob->substitute = pcrs_compile_replacement(token, errptr)) == NULL) - { - pcrs_free_job(newjob); - return NULL; - } - else - { - break; - } - /* The options */ - case 3: - newjob->options = pcrs_compile_perl_options(token, &globalflag); - newjob->globalflag = globalflag; - break; +/********************************************************************* + * + * 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 = ""; - /* There shouldn't be anything else! */ - default: - *errptr = PCRS_ERR_CMDSYNTAX; - pcrs_free_job(newjob); - return NULL; - } - i++; - } - free(token); - /* We have a valid substitute? */ - if (newjob->substitute == NULL) + /* + * Get and init memory + */ + if (NULL == (newjob = (pcrs_job *)malloc(sizeof(pcrs_job)))) { - *errptr = PCRS_ERR_CMDSYNTAX; - pcrs_free_job(newjob); + *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(dummy, newjob->options, &error, errptr, NULL); + + /* + * Compile the pattern + */ + newjob->pattern = pcre_compile(pattern, newjob->options, &error, errptr, NULL); if (newjob->pattern == NULL) { pcrs_free_job(newjob); return NULL; } - free(dummy); + /* * Generate hints. This has little overhead, since the @@ -455,7 +641,28 @@ pcrs_job *pcrs_make_job(char *command, int *errptr) 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; } @@ -463,98 +670,165 @@ pcrs_job *pcrs_make_job(char *command, int *errptr) /********************************************************************* * - * Function : create_pcrs_job + * Function : pcrs_execute_list * - * Description : Create a job from all its components, if you don't - * have a Perl command to start from. Rather boring. + * 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. * * Parameters : - * 1 : pattern = pointer to pcre pattern - * 2 : hints = pointer to pcre hints - * 3 : options = options in pcre format - * 4 : globalflag = flag that indicates if global matching is desired - * 5 : substitute = pointer to pcrs_substitute data structure - * 2 : errptr = pointer to an integer in which error - * conditions can be returned. + * 1 : joblist = the chained list of pcrs_jobs to be executed + * 2 : subject = the subject string + * 3 : subject_length = the subject's length + * INCLUDING the terminating zero, if string! + * 4 : result = char** for returning the result + * 5 : result_length = size_t* for returning the result's length * - * Returns : pcrs_job structure, or NULL if an error was encountered. - * In that case, *errptr has the reason why. + * Returns : On success, the number of substitutions that were made. + * May be > 1 if job->flags contained PCRS_GLOBAL + * On failiure, the (negative) pcre error code describing the + * failiure, which may be translated to text using pcrs_strerror(). * *********************************************************************/ -pcrs_job *create_pcrs_job(pcre *pattern, pcre_extra *hints, int options, int globalflag, pcrs_substitute *substitute, int *errptr) +int pcrs_execute_list(pcrs_job *joblist, char *subject, size_t subject_length, char **result, size_t *result_length) { - pcrs_job *newjob; - - if ((newjob = (pcrs_job *)malloc(sizeof(pcrs_job))) == NULL) + pcrs_job *job; + char *old, *new; + int hits, total_hits; + + old = subject; + *result_length = subject_length; + hits = total_hits = 0; + + for (job = joblist; job != NULL; job = job->next) { - *errptr = PCRS_ERR_NOMEM; - return NULL; - } - memset(newjob, '\0', sizeof(pcrs_job)); + hits = pcrs_execute(job, old, *result_length, &new, result_length); - newjob->pattern = pattern; - newjob->hints = hints; - newjob->options = options; - newjob->globalflag = globalflag; - newjob->substitute = substitute; + if (old != subject) free(old); - return(newjob); + if (hits < 0) + { + return(hits); + } + else + { + total_hits += hits; + old = new; + } + } + + *result = new; + return(total_hits); } /********************************************************************* * - * Function : pcrs_exec_substitution + * Function : pcrs_execute * - * Description : Modify the subject by executing the regular substitution - * defined by the job. Since the result may be longer than - * the subject, its space requirements are precalculated in - * the matching phase and new memory is allocated accordingly. - * It is the caller's responsibility to free the result when - * it's no longer needed. + * 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. * * Parameters : * 1 : job = the pcrs_job to be executed * 2 : subject = the subject (== original) string - * 3 : subject_length = the subject's length + * 3 : subject_length = the subject's length + * INCLUDING the terminating zero, if string! * 4 : result = char** for returning the result - * 5 : result_length = int* for returning the result's length + * 5 : result_length = size_t* for returning the result's length * - * Returns : the number of substitutions that were made. May be > 1 - * if job->globalflag was set + * Returns : On success, the number of substitutions that were made. + * May be > 1 if job->flags contained PCRS_GLOBAL + * On failiure, the (negative) pcre error code describing the + * failiure, which may be translated to text using pcrs_strerror(). * *********************************************************************/ -int pcrs_exec_substitution(pcrs_job *job, char *subject, int subject_length, char **result, int *result_length) +int pcrs_execute(pcrs_job *job, char *subject, size_t subject_length, char **result, size_t *result_length) { int offsets[3 * PCRS_MAX_SUBMATCHES], - offset = 0, i=0, k, matches_found, newsize, submatches; - pcrs_match matches[PCRS_MAX_MATCHES]; + offset, i, k, + matches_found, + newsize, + submatches, + max_matches = PCRS_MAX_MATCH_INIT; + pcrs_match *matches, *dummy; char *result_offset; - /* Sanity first */ + offset = i = k = 0; + + /* + * Sanity check & memory allocation + */ if (job == NULL || job->pattern == NULL || job->substitute == NULL) { *result = NULL; return(PCRS_ERR_BADJOB); } + if (NULL == (matches = (pcrs_match *)malloc(max_matches * sizeof(pcrs_match)))) + { + *result = NULL; + return(PCRS_ERR_NOMEM); + } + memset(matches, '\0', max_matches * sizeof(pcrs_match)); + + + /* + * Find the pattern and calculate the space + * requirements for the result + */ newsize=subject_length; - /* Find.. */ - while ((submatches = pcre_exec(job->pattern, job->hints, subject, subject_length, offset, 0, offsets, 99)) > 0) + while ((submatches = pcre_exec(job->pattern, job->hints, subject, 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]; - matches[i].submatch_length[k] = offsets[2 * k + 1] - offsets[2 * k]; /* Non-found optional submatches have length -1-(-1)==0 */ - newsize += matches[i].submatch_length[k] * job->substitute->backref_count[k]; /* reserve mem for each submatch as often as it is ref'd */ + + /* Note: Non-found optional submatches have length -1-(-1)==0 */ + matches[i].submatch_length[k] = 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] * job->substitute->backref_count[k]; + } + /* plus replacement text size minus match text size */ + newsize += strlen(job->substitute->text) - matches[i].submatch_length[0]; + + /* chunk before match */ + matches[i].submatch_offset[PCRS_MAX_SUBMATCHES] = 0; + matches[i].submatch_length[PCRS_MAX_SUBMATCHES] = offsets[0]; + newsize += offsets[0] * 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 - offsets[1] - 1; + newsize += (subject_length - offsets[1]) * job->substitute->backref_count[PCRS_MAX_SUBMATCHES + 1]; + + /* Storage for matches exhausted? -> Extend! */ + if (++i >= max_matches) + { + max_matches *= PCRS_MAX_MATCH_GROW; + if (NULL == (dummy = (pcrs_match *)realloc(matches, max_matches * sizeof(pcrs_match)))) + { + free(matches); + *result = NULL; + return(PCRS_ERR_NOMEM); + } + matches = dummy; } - newsize += strlen(job->substitute->text) - matches[i].submatch_length[0]; /* plus replacement text size minus match text size */ /* Non-global search or limit reached? */ - if (++i >= PCRS_MAX_MATCHES || !job->globalflag ) break; + if (!(job->flags & PCRS_GLOBAL)) break; /* Don't loop on empty matches */ if (offsets[1] == offset) @@ -566,22 +840,35 @@ int pcrs_exec_substitution(pcrs_job *job, char *subject, int subject_length, cha else offset = offsets[1]; } - if (submatches < -1) return submatches; /* Pass pcre error through */ + /* Pass pcre error through if (bad) failiure */ + if (submatches < PCRE_ERROR_NOMATCH) + { + free(matches); + return submatches; + } matches_found = i; - /* ..get memory ..*/ + + /* + * Get memory for the result + */ if ((*result = (char *)malloc(newsize)) == NULL) /* must be free()d by caller */ { + free(matches); return PCRS_ERR_NOMEM; } - /* ..and replace */ + + /* + * Replace + */ offset = 0; result_offset = *result; for (i=0; i < matches_found; i++) { - memcpy(result_offset, subject + offset, matches[i].submatch_offset[0] - offset); /* copy the chunk preceding the match */ + /* copy the chunk preceding the match */ + memcpy(result_offset, subject + offset, matches[i].submatch_offset[0] - offset); result_offset += matches[i].submatch_offset[0] - offset; /* For every segment of the substitute.. */ @@ -591,14 +878,14 @@ int pcrs_exec_substitution(pcrs_job *job, char *subject, int subject_length, cha 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).. */ + /* ..plus, if it's not the last chunk, i.e.: There *is* a backref.. */ if (k != job->substitute->backrefs - /* ..and a nonempty match.. */ - && matches[i].submatch_length[job->substitute->backref[k]] > 0 - /* ..and in legal range, ... */ - && job->substitute->backref[k] <= PCRS_MAX_SUBMATCHES) + /* ..in legal range.. */ + && job->substitute->backref[k] < PCRS_MAX_SUBMATCHES + 2 + /* ..and referencing a nonempty match.. */ + && matches[i].submatch_length[job->substitute->backref[k]] > 0) { - /* copy the submatch that is ref'd. */ + /* ..copy the submatch that is ref'd. */ memcpy( result_offset, subject + matches[i].submatch_offset[job->substitute->backref[k]], @@ -614,6 +901,7 @@ int pcrs_exec_substitution(pcrs_job *job, char *subject, int subject_length, cha memcpy(result_offset, subject + offset, subject_length - offset); *result_length = newsize; + free(matches); return matches_found; }