Annotation of parser3/src/lib/pcre/get.c, revision 1.1
1.1 ! paf 1: /*************************************************
! 2: * Perl-Compatible Regular Expressions *
! 3: *************************************************/
! 4:
! 5: /*
! 6: This is a library of functions to support regular expressions whose syntax
! 7: and semantics are as close as possible to those of the Perl 5 language. See
! 8: the file Tech.Notes for some information on the internals.
! 9:
! 10: Written by: Philip Hazel <ph10@cam.ac.uk>
! 11:
! 12: Copyright (c) 1997-1999 University of Cambridge
! 13:
! 14: -----------------------------------------------------------------------------
! 15: Permission is granted to anyone to use this software for any purpose on any
! 16: computer system, and to redistribute it freely, subject to the following
! 17: restrictions:
! 18:
! 19: 1. This software is distributed in the hope that it will be useful,
! 20: but WITHOUT ANY WARRANTY; without even the implied warranty of
! 21: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
! 22:
! 23: 2. The origin of this software must not be misrepresented, either by
! 24: explicit claim or by omission.
! 25:
! 26: 3. Altered versions must be plainly marked as such, and must not be
! 27: misrepresented as being the original software.
! 28:
! 29: 4. If PCRE is embedded in any software that is released under the GNU
! 30: General Purpose Licence (GPL), then the terms of that licence shall
! 31: supersede any condition above with which it is incompatible.
! 32: -----------------------------------------------------------------------------
! 33: */
! 34:
! 35: /* This module contains some convenience functions for extracting substrings
! 36: from the subject string after a regex match has succeeded. The original idea
! 37: for these functions came from Scott Wimer <scottw@cgibuilder.com>. */
! 38:
! 39:
! 40: /* Include the internals header, which itself includes Standard C headers plus
! 41: the external pcre header. */
! 42:
! 43: #include "internal.h"
! 44:
! 45:
! 46:
! 47: /*************************************************
! 48: * Copy captured string to given buffer *
! 49: *************************************************/
! 50:
! 51: /* This function copies a single captured substring into a given buffer.
! 52: Note that we use memcpy() rather than strncpy() in case there are binary zeros
! 53: in the string.
! 54:
! 55: Arguments:
! 56: subject the subject string that was matched
! 57: ovector pointer to the offsets table
! 58: stringcount the number of substrings that were captured
! 59: (i.e. the yield of the pcre_exec call, unless
! 60: that was zero, in which case it should be 1/3
! 61: of the offset table size)
! 62: stringnumber the number of the required substring
! 63: buffer where to put the substring
! 64: size the size of the buffer
! 65:
! 66: Returns: if successful:
! 67: the length of the copied string, not including the zero
! 68: that is put on the end; can be zero
! 69: if not successful:
! 70: PCRE_ERROR_NOMEMORY (-6) buffer too small
! 71: PCRE_ERROR_NOSUBSTRING (-7) no such captured substring
! 72: */
! 73:
! 74: int
! 75: pcre_copy_substring(const char *subject, int *ovector, int stringcount,
! 76: int stringnumber, char *buffer, int size)
! 77: {
! 78: int yield;
! 79: if (stringnumber < 0 || stringnumber >= stringcount)
! 80: return PCRE_ERROR_NOSUBSTRING;
! 81: stringnumber *= 2;
! 82: yield = ovector[stringnumber+1] - ovector[stringnumber];
! 83: if (size < yield + 1) return PCRE_ERROR_NOMEMORY;
! 84: memcpy(buffer, subject + ovector[stringnumber], yield);
! 85: buffer[yield] = 0;
! 86: return yield;
! 87: }
! 88:
! 89:
! 90:
! 91: /*************************************************
! 92: * Copy all captured strings to new store *
! 93: *************************************************/
! 94:
! 95: /* This function gets one chunk of store and builds a list of pointers and all
! 96: of the captured substrings in it. A NULL pointer is put on the end of the list.
! 97:
! 98: Arguments:
! 99: subject the subject string that was matched
! 100: ovector pointer to the offsets table
! 101: stringcount the number of substrings that were captured
! 102: (i.e. the yield of the pcre_exec call, unless
! 103: that was zero, in which case it should be 1/3
! 104: of the offset table size)
! 105: listptr set to point to the list of pointers
! 106:
! 107: Returns: if successful: 0
! 108: if not successful:
! 109: PCRE_ERROR_NOMEMORY (-6) failed to get store
! 110: */
! 111:
! 112: int
! 113: pcre_get_substring_list(const char *subject, int *ovector, int stringcount,
! 114: const char ***listptr)
! 115: {
! 116: int i;
! 117: int size = sizeof(char *);
! 118: int double_count = stringcount * 2;
! 119: char **stringlist;
! 120: char *p;
! 121:
! 122: for (i = 0; i < double_count; i += 2)
! 123: size += sizeof(char *) + ovector[i+1] - ovector[i] + 1;
! 124:
! 125: stringlist = (char **)(pcre_malloc)(size);
! 126: if (stringlist == NULL) return PCRE_ERROR_NOMEMORY;
! 127:
! 128: *listptr = (const char **)stringlist;
! 129: p = (char *)(stringlist + stringcount + 1);
! 130:
! 131: for (i = 0; i < double_count; i += 2)
! 132: {
! 133: int len = ovector[i+1] - ovector[i];
! 134: memcpy(p, subject + ovector[i], len);
! 135: *stringlist++ = p;
! 136: p += len;
! 137: *p++ = 0;
! 138: }
! 139:
! 140: *stringlist = NULL;
! 141: return 0;
! 142: }
! 143:
! 144:
! 145:
! 146: /*************************************************
! 147: * Copy captured string to new store *
! 148: *************************************************/
! 149:
! 150: /* This function copies a single captured substring into a piece of new
! 151: store
! 152:
! 153: Arguments:
! 154: subject the subject string that was matched
! 155: ovector pointer to the offsets table
! 156: stringcount the number of substrings that were captured
! 157: (i.e. the yield of the pcre_exec call, unless
! 158: that was zero, in which case it should be 1/3
! 159: of the offset table size)
! 160: stringnumber the number of the required substring
! 161: stringptr where to put a pointer to the substring
! 162:
! 163: Returns: if successful:
! 164: the length of the string, not including the zero that
! 165: is put on the end; can be zero
! 166: if not successful:
! 167: PCRE_ERROR_NOMEMORY (-6) failed to get store
! 168: PCRE_ERROR_NOSUBSTRING (-7) substring not present
! 169: */
! 170:
! 171: int
! 172: pcre_get_substring(const char *subject, int *ovector, int stringcount,
! 173: int stringnumber, const char **stringptr)
! 174: {
! 175: int yield;
! 176: char *substring;
! 177: if (stringnumber < 0 || stringnumber >= stringcount)
! 178: return PCRE_ERROR_NOSUBSTRING;
! 179: stringnumber *= 2;
! 180: yield = ovector[stringnumber+1] - ovector[stringnumber];
! 181: substring = (char *)(pcre_malloc)(yield + 1);
! 182: if (substring == NULL) return PCRE_ERROR_NOMEMORY;
! 183: memcpy(substring, subject + ovector[stringnumber], yield);
! 184: substring[yield] = 0;
! 185: *stringptr = substring;
! 186: return yield;
! 187: }
! 188:
! 189: /* End of get.c */
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