-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 1.7 2001/06/29 13:33:04 oes Exp $";
/*********************************************************************
*
* Currently, there's no documentation besides comments and the
* source itself ;-)
*
- * Copyright : Written and Copyright (C) 2000 by Andreas Oesterhelt
+ * Short note: I addition to perl's options, 'U' for ungreedy
+ * and 't' for trivial (i.e.: ignore backrefs in the substitute)
+ * are supported.
+ *
+ * Copyright : Written and Copyright (C) 2000, 2001 by Andreas S. Oesterhelt
* <andreas@oesterhelt.org>
*
* This program is free software; you can redistribute it
*
* Revisions :
* $Log: pcrs.c,v $
+ * 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
+ * - Removed logentry from cancelled commit
+ *
+ * Revision 1.6 2001/06/03 19:12:45 oes
+ * added FIXME
+ *
+ * Revision 1.5 2001/05/29 09:50:24 jongfoster
+ * Unified blocklist/imagelist/permissionslist.
+ * File format is still under discussion, but the internal changes
+ * are (mostly) done.
+ *
+ * Also modified interceptor behaviour:
+ * - We now intercept all URLs beginning with one of the following
+ * prefixes (and *only* these prefixes):
+ * * http://i.j.b/
+ * * http://ijbswa.sf.net/config/
+ * * http://ijbswa.sourceforge.net/config/
+ * - New interceptors "home page" - go to http://i.j.b/ to see it.
+ * - Internal changes so that intercepted and fast redirect pages
+ * are not replaced with an image.
+ * - Interceptors now have the option to send a binary page direct
+ * to the client. (i.e. ijb-send-banner uses this)
+ * - Implemented show-url-info interceptor. (Which is why I needed
+ * the above interceptors changes - a typical URL is
+ * "http://i.j.b/show-url-info?url=www.somesite.com/banner.gif".
+ * The previous mechanism would not have intercepted that, and
+ * if it had been intercepted then it then it would have replaced
+ * it with an image.)
+ *
+ * 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
*
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'.
- *
- * Parameters :
- * 1 : token = current token
- * 2 : text = string to tokenize
- * 3 : delimiter = single character deliminter
- * 4 : quote_char = character to cause quoting
- *
- * Returns : -1 => failure, else the length of the token found.
- * In the latter case, *text is the token's start.
- *
- *********************************************************************/
-int my_strsep(char *token, char **text, char delimiter, char quote_char)
-{
- 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 (text[0][i] == delimiter && !quoted)
- {
- *text += 1;
- break;
- }
- 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;
-
-}
-
-
/*********************************************************************
*
* Function : pcrs_compile_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_compile_perl_options(char *optstring, int *flags)
{
- int i, rc = 0;
- *globalflag = 0;
+ size_t i;
+ int rc = 0;
+ *flags = 0;
for (i=0; i < strlen(optstring); i++)
{
switch(optstring[i])
{
case 'e': break;
- case 'g': *globalflag = 1; break;
+ 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;
}
}
* the reason.
*
*********************************************************************/
-pcrs_substitute *pcrs_compile_replacement(char *replacement, int *errptr)
+pcrs_substitute *pcrs_compile_replacement(char *replacement, int trivialflag, int *errptr)
{
int length, i, k = 0, l = 0, quoted = 0, idx;
char *text, *num_ptr, *numbers = "0123456789";
length = strlen(replacement);
- for (i=0; i < length; i++)
+ if (trivialflag)
{
- /* Backslash treatment */
- if (replacement[i] == '\\')
+ k = length;
+ }
+ else
+ {
+ for (i=0; i < length; i++)
{
- if (quoted)
+ /* Backslash treatment */
+ if (replacement[i] == '\\')
{
- text[k++] = replacement[i];
- quoted = 0;
- }
- else
- {
- quoted = 1;
+ if (quoted)
+ {
+ text[k++] = replacement[i];
+ quoted = 0;
+ }
+ else
+ {
+ quoted = 1;
+ }
+ continue;
}
- continue;
- }
- /* Dollar treatment */
- if (replacement[i] == '$' && !quoted && i < length - 1)
- {
- if (strchr("0123456789&", replacement[i + 1]) == NULL)
- {
- text[k++] = replacement[i];
- }
- else
+ /* Dollar treatment */
+ if (replacement[i] == '$' && !quoted && i < length - 1)
{
- r->block_length[l] = k - r->block_offset[l];
- r->backref[l] = 0;
- if (replacement[i + 1] != '&')
+ if (strchr("0123456789&", replacement[i + 1]) == NULL)
{
- while ((num_ptr = strchr(numbers, replacement[++i])) != NULL && i < length)
+ text[k++] = replacement[i];
+ }
+ else
+ {
+ r->block_length[l] = k - r->block_offset[l];
+ r->backref[l] = 0;
+ if (replacement[i + 1] != '&')
{
- idx = num_ptr - numbers;
- r->backref[l] = r->backref[l] * 10 + idx;
+ while ((num_ptr = strchr(numbers, replacement[++i])) != NULL && i < length)
+ {
+ idx = num_ptr - numbers;
+ r->backref[l] = r->backref[l] * 10 + idx;
+ }
+ i--;
}
- i--;
+ else
+ i++;
+ if (r->backref[l] < PCRS_MAX_SUBMATCHES)
+ r->backref_count[r->backref[l]] += 1;
+ l++;
+ r->block_offset[l] = k;
}
- else
- i++;
- if (r->backref[l] < PCRS_MAX_SUBMATCHES)
- r->backref_count[r->backref[l]] += 1;
- l++;
- r->block_offset[l] = k;
+ continue;
}
- continue;
- }
- /* Plain char treatment */
- text[k++] = replacement[i];
- quoted = 0;
- }
+ /* Plain char treatment */
+ text[k++] = replacement[i];
+ quoted = 0;
+ }
+ } /* -END- if (!trivialflag) */
text[k] = '\0';
r->text = text;
* 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)
}
+/*********************************************************************
+ *
+ * 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_make_job
+ * Function : pcrs_compile
*
* 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.
*
* Parameters :
* 1 : command = string with perl-style s/// command
* has the reason.
*
*********************************************************************/
-pcrs_job *pcrs_make_job(char *command, int *errptr)
+pcrs_job *pcrs_compile(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)
- {
- *errptr = PCRS_ERR_NOMEM;
- return NULL;
- }
- memset(newjob, '\0', sizeof(pcrs_job));
+ i = k = l = 0;
- /* Command too short? */
- if (strlen(command) < 4)
+ /*
+ * Tokenize the perl command
+ */
+ limit = strlen(command);
+ if (limit < 4)
{
*errptr = PCRS_ERR_CMDSYNTAX;
- pcrs_free_job(newjob);
return NULL;
}
-
- /* 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)
+ else
{
- switch (i)
- {
- /* We don't care about the command and assume 's' */
- case 0:
- break;
+ delimiter = command[1];
+ }
- /* The pattern */
- case 1:
- strcpy(dummy, token);
- break;
+ tokens[l] = (char *) malloc(limit + 1);
- /* The substitute */
- case 2:
- if ((newjob->substitute = pcrs_compile_replacement(token, errptr)) == NULL)
- {
- pcrs_free_job(newjob);
- return NULL;
- }
- else
- {
- break;
- }
+ for (i=0; i <= limit; i++)
+ {
- /* The options */
- case 3:
- newjob->options = pcrs_compile_perl_options(token, &globalflag);
- newjob->globalflag = globalflag;
+ if (command[i] == delimiter && !quoted)
+ {
+ if (l == 3)
+ {
+ l = -1;
break;
-
- /* There shouldn't be anything else! */
- default:
- *errptr = PCRS_ERR_CMDSYNTAX;
- pcrs_free_job(newjob);
- return NULL;
+ }
+ tokens[0][k++] = '\0';
+ tokens[++l] = tokens[0] + k;
+ continue;
}
- i++;
- }
- free(token);
- /* We have a valid substitute? */
- if (newjob->substitute == NULL)
- {
- *errptr = PCRS_ERR_CMDSYNTAX;
- pcrs_free_job(newjob);
- return NULL;
+ else if (command[i] == '\\' && !quoted && i+1 < limit && command[i+1] == delimiter)
+ {
+ quoted = TRUE;
+ continue;
+ }
+ tokens[0][k++] = command[i];
+ quoted = FALSE;
}
- /* Compile the pattern */
- newjob->pattern = pcre_compile(dummy, 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
- * hints will be NULL for a boring pattern anyway.
+ * Syntax error ?
*/
- newjob->hints = pcre_study(newjob->pattern, 0, &error);
- if (error != NULL)
+ if (l != 3)
{
- *errptr = PCRS_ERR_STUDY;
- pcrs_free_job(newjob);
+ *errptr = PCRS_ERR_CMDSYNTAX;
+ free(tokens[0]);
return NULL;
}
+ newjob = pcrs_make_job(tokens[1], tokens[2], tokens[3], errptr);
+ free(tokens[0]);
return newjob;
}
/*********************************************************************
*
- * Function : create_pcrs_job
+ * Function : pcrs_make_job
*
- * Description : Create a job from all its components, if you don't
- * have a Perl command to start from. Rather boring.
+ * Description : Takes the three arguments to a perl s/// command
+ * and compiles a pcrs_job structure from them.
*
* 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
+ * 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 : pcrs_job structure, or NULL if an error was encountered.
- * In that case, *errptr has the reason why.
+ * Returns : a corresponding pcrs_job data structure, or NULL
+ * if an error was encountered. In that case, *errptr
+ * has the reason.
*
*********************************************************************/
-pcrs_job *create_pcrs_job(pcre *pattern, pcre_extra *hints, int options, int globalflag, pcrs_substitute *substitute, int *errptr)
+pcrs_job *pcrs_make_job(char *pattern, char *substitute, char *options, int *errptr)
{
pcrs_job *newjob;
+ int flags;
+ const char *error;
+
+ /*
+ * Handle NULL arguments
+ */
+ if (pattern == NULL) pattern = "";
+ if (substitute == NULL) substitute = "";
+ if (options == NULL) options = "";
- if ((newjob = (pcrs_job *)malloc(sizeof(pcrs_job))) == NULL)
+ /*
+ * 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));
- newjob->pattern = pattern;
- newjob->hints = hints;
- newjob->options = options;
- newjob->globalflag = globalflag;
- newjob->substitute = substitute;
- return(newjob);
+ /*
+ * Evaluate the options
+ */
+ newjob->options = pcrs_compile_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;
+ }
+
+
+ /*
+ * Compile the substitute
+ */
+ if (NULL == (newjob->substitute = pcrs_compile_replacement(substitute, newjob->flags & PCRS_TRIVIAL, errptr)))
+ {
+ pcrs_free_job(newjob);
+ return NULL;
+ }
+
+ return newjob;
}
/*********************************************************************
*
- * 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
* 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
*
* Returns : the number of substitutions that were made. May be > 1
- * if job->globalflag was set
+ * if job->flags contained PCRS_GLOBAL
*
*********************************************************************/
-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, int subject_length, char **result, int *result_length)
{
int offsets[3 * PCRS_MAX_SUBMATCHES],
- offset = 0, i=0, k, matches_found, newsize, submatches;
+ offset, i, k,
+ matches_found,
+ newsize,
+ submatches;
pcrs_match matches[PCRS_MAX_MATCHES];
char *result_offset;
- /* Sanity first */
+ offset = i = k = 0;
+
+ /*
+ * Sanity check
+ */
if (job == NULL || job->pattern == NULL || job->substitute == NULL)
{
*result = NULL;
return(PCRS_ERR_BADJOB);
}
+
+ /*
+ * Find the pattern and calculate the space
+ * requirements for the result (newsize)
+ */
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];
}
- newsize += strlen(job->substitute->text) - matches[i].submatch_length[0]; /* plus replacement text size minus match text size */
+ /* plus replacement text size minus match text size */
+ newsize += strlen(job->substitute->text) - matches[i].submatch_length[0];
/* Non-global search or limit reached? */
- if (++i >= PCRS_MAX_MATCHES || !job->globalflag ) break;
+ if (++i >= PCRS_MAX_MATCHES || !(job->flags & PCRS_GLOBAL) ) break;
/* Don't loop on empty matches */
if (offsets[1] == offset)
else
offset = offsets[1];
}
- if (submatches < -1) return submatches; /* Pass pcre error through */
+ /* Pass pcre error through if failiure*/
+ if (submatches < -1) return submatches;
matches_found = i;
- /* ..get memory ..*/
+
+ /*
+ * Get memory for the result
+ */
if ((*result = (char *)malloc(newsize)) == NULL) /* must be free()d by caller */
{
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.. */
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