const char pcrs_rcs[] = "$Id: pcrs.c,v 1.42 2012/05/24 15:04:34 fabiankeil Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/pcrs.c,v $ * * 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. * * 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additional functions and bug * fixes that aren't part of the latest official pcrs package * (which apparently is no longer maintained).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 * * * Copyright (C) 2006, 2007 Fabian Keil * * 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. * *********************************************************************/ #include #include #include /* * Include project.h just so that the right pcre.h gets * included from there */ #include "project.h" /* For snprintf only */ #include "miscutil.h" /* For xtoi */ #include "encode.h" #include "pcrs.h" const char pcrs_h_rcs[] = PCRS_H_VERSION; /* * Internal prototypes */ static int pcrs_parse_perl_options(const char *optstring, int *flags); static pcrs_substitute *pcrs_compile_replacement(const char *replacement, int trivialflag, 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"; 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 $` */ { r->backref[l] = (int)(PCRS_MAX_SUBMATCHES + 1 - (symbol - symbols)); } i += 2; } /* Invalid backref -> plain '$' */ 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 * dependent 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; 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; 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 = 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. */ static const char delimiters[] = "><#+*~%^-:;!@"; const 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 : pcrs_command = The dynamic pcrs command to compile * 2 : v = NULL terminated array of variables and their values. * 3 : 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: */