/************************************************* * Perl-Compatible Regular Expressions * *************************************************/ /* PCRE is a library of functions to support regular expressions whose syntax and semantics are as close as possible to those of the Perl 5 language. Written by Philip Hazel Copyright (c) 1997-2005 University of Cambridge ----------------------------------------------------------------------------- Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the University of Cambridge nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ----------------------------------------------------------------------------- */ /* This module contains some convenience functions for extracting substrings from the subject string after a regex match has succeeded. The original idea for these functions came from Scott Wimer. */ #include "pcre_internal.h" #include <wtf/UnusedParam.h> /************************************************* * Find number for named string * *************************************************/ /* This function is used by the two extraction functions below, as well as being generally available. Arguments: code the compiled regex stringname the name whose number is required Returns: the number of the named parentheses, or a negative number (PCRE_ERROR_NOSUBSTRING) if not found */ int pcre_get_stringnumber(const pcre *code, const pcre_char *stringname) { /* FIXME: This doesn't work for UTF-16 because the name table has 8-bit characters in it! */ #if !PCRE_UTF16 int rc; int entrysize; int top, bot; uschar *nametable; if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMECOUNT, &top)) != 0) return rc; if (top <= 0) return PCRE_ERROR_NOSUBSTRING; if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMEENTRYSIZE, &entrysize)) != 0) return rc; if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMETABLE, &nametable)) != 0) return rc; bot = 0; while (top > bot) { int mid = (top + bot) / 2; uschar *entry = nametable + entrysize*mid; int c = strcmp(stringname, (char *)(entry + 2)); if (c == 0) return (entry[0] << 8) + entry[1]; if (c > 0) bot = mid + 1; else top = mid; } #else UNUSED_PARAM(code); UNUSED_PARAM(stringname); #endif return PCRE_ERROR_NOSUBSTRING; } /************************************************* * Copy captured string to given buffer * *************************************************/ /* This function copies a single captured substring into a given buffer. Note that we use memcpy() rather than strncpy() in case there are binary zeros in the string. Arguments: subject the subject string that was matched ovector pointer to the offsets table stringcount the number of substrings that were captured (i.e. the yield of the pcre_exec call, unless that was zero, in which case it should be 1/3 of the offset table size) stringnumber the number of the required substring buffer where to put the substring size the size of the buffer Returns: if successful: the length of the copied string, not including the zero that is put on the end; can be zero if not successful: PCRE_ERROR_NOMEMORY (-6) buffer too small PCRE_ERROR_NOSUBSTRING (-7) no such captured substring */ int pcre_copy_substring(const pcre_char *subject, int *ovector, int stringcount, int stringnumber, pcre_char *buffer, int size) { int yield; if (stringnumber < 0 || stringnumber >= stringcount) return PCRE_ERROR_NOSUBSTRING; stringnumber *= 2; yield = ovector[stringnumber+1] - ovector[stringnumber]; if (size < yield + 1) return PCRE_ERROR_NOMEMORY; memcpy(buffer, subject + ovector[stringnumber], yield); buffer[yield] = 0; return yield; } /************************************************* * Copy named captured string to given buffer * *************************************************/ /* This function copies a single captured substring into a given buffer, identifying it by name. Arguments: code the compiled regex subject the subject string that was matched ovector pointer to the offsets table stringcount the number of substrings that were captured (i.e. the yield of the pcre_exec call, unless that was zero, in which case it should be 1/3 of the offset table size) stringname the name of the required substring buffer where to put the substring size the size of the buffer Returns: if successful: the length of the copied string, not including the zero that is put on the end; can be zero if not successful: PCRE_ERROR_NOMEMORY (-6) buffer too small PCRE_ERROR_NOSUBSTRING (-7) no such captured substring */ int pcre_copy_named_substring(const pcre *code, const pcre_char *subject, int *ovector, int stringcount, const pcre_char *stringname, pcre_char *buffer, int size) { int n = pcre_get_stringnumber(code, stringname); if (n <= 0) return n; return pcre_copy_substring(subject, ovector, stringcount, n, buffer, size); } /************************************************* * Copy all captured strings to new store * *************************************************/ /* This function gets one chunk of store and builds a list of pointers and all of the captured substrings in it. A NULL pointer is put on the end of the list. Arguments: subject the subject string that was matched ovector pointer to the offsets table stringcount the number of substrings that were captured (i.e. the yield of the pcre_exec call, unless that was zero, in which case it should be 1/3 of the offset table size) listptr set to point to the list of pointers Returns: if successful: 0 if not successful: PCRE_ERROR_NOMEMORY (-6) failed to get store */ int pcre_get_substring_list(const pcre_char *subject, int *ovector, int stringcount, const pcre_char ***listptr) { int i; int size = sizeof(char *); int double_count = stringcount * 2; pcre_char **stringlist; pcre_char *p; for (i = 0; i < double_count; i += 2) size += sizeof(pcre_char *) + (ovector[i+1] - ovector[i] + 1) * sizeof(pcre_char); stringlist = (pcre_char **)(pcre_malloc)(size); if (stringlist == NULL) return PCRE_ERROR_NOMEMORY; *listptr = (const pcre_char **)stringlist; p = (pcre_char *)(stringlist + stringcount + 1); for (i = 0; i < double_count; i += 2) { int len = ovector[i+1] - ovector[i]; memcpy(p, subject + ovector[i], len * sizeof(pcre_char)); *stringlist++ = p; p += len; *p++ = 0; } *stringlist = NULL; return 0; } /************************************************* * Free store obtained by get_substring_list * *************************************************/ /* This function exists for the benefit of people calling PCRE from non-C programs that can call its functions, but not free() or (pcre_free)() directly. Argument: the result of a previous pcre_get_substring_list() Returns: nothing */ void pcre_free_substring_list(const pcre_char **pointer) { (pcre_free)((void *)pointer); } /************************************************* * Copy captured string to new store * *************************************************/ /* This function copies a single captured substring into a piece of new store Arguments: subject the subject string that was matched ovector pointer to the offsets table stringcount the number of substrings that were captured (i.e. the yield of the pcre_exec call, unless that was zero, in which case it should be 1/3 of the offset table size) stringnumber the number of the required substring stringptr where to put a pointer to the substring Returns: if successful: the length of the string, not including the zero that is put on the end; can be zero if not successful: PCRE_ERROR_NOMEMORY (-6) failed to get store PCRE_ERROR_NOSUBSTRING (-7) substring not present */ int pcre_get_substring(const pcre_char *subject, int *ovector, int stringcount, int stringnumber, const pcre_char **stringptr) { int yield; pcre_char *substring; if (stringnumber < 0 || stringnumber >= stringcount) return PCRE_ERROR_NOSUBSTRING; stringnumber *= 2; yield = ovector[stringnumber+1] - ovector[stringnumber]; substring = (pcre_char *)(pcre_malloc)((yield + 1) * sizeof(pcre_char)); if (substring == NULL) return PCRE_ERROR_NOMEMORY; memcpy(substring, subject + ovector[stringnumber], yield * sizeof(pcre_char)); substring[yield] = 0; *stringptr = substring; return yield; } /************************************************* * Copy named captured string to new store * *************************************************/ /* This function copies a single captured substring, identified by name, into new store. Arguments: code the compiled regex subject the subject string that was matched ovector pointer to the offsets table stringcount the number of substrings that were captured (i.e. the yield of the pcre_exec call, unless that was zero, in which case it should be 1/3 of the offset table size) stringname the name of the required substring stringptr where to put the pointer Returns: if successful: the length of the copied string, not including the zero that is put on the end; can be zero if not successful: PCRE_ERROR_NOMEMORY (-6) couldn't get memory PCRE_ERROR_NOSUBSTRING (-7) no such captured substring */ int pcre_get_named_substring(const pcre *code, const pcre_char *subject, int *ovector, int stringcount, const pcre_char *stringname, const pcre_char **stringptr) { int n = pcre_get_stringnumber(code, stringname); if (n <= 0) return n; return pcre_get_substring(subject, ovector, stringcount, n, stringptr); } /************************************************* * Free store obtained by get_substring * *************************************************/ /* This function exists for the benefit of people calling PCRE from non-C programs that can call its functions, but not free() or (pcre_free)() directly. Argument: the result of a previous pcre_get_substring() Returns: nothing */ void pcre_free_substring(const pcre_char *pointer) { (pcre_free)((void *)pointer); } /* End of pcre_get.c */