Mercurial > hg > octave-kai > gnulib-hg
annotate lib/strcasestr.c @ 6164:83bee8e13391
Include a header, to define NULL.
| author | Bruno Haible <bruno@clisp.org> |
|---|---|
| date | Wed, 31 Aug 2005 11:51:18 +0000 |
| parents | 199c20f568d7 |
| children | 1c4ed7637c24 |
| rev | line source |
|---|---|
| 6058 | 1 /* Case-insensitive searching in a string. |
| 2 Copyright (C) 2005 Free Software Foundation, Inc. | |
| 3 Written by Bruno Haible <bruno@clisp.org>, 2005. | |
| 4 | |
| 5 This program is free software; you can redistribute it and/or modify | |
| 6 it under the terms of the GNU General Public License as published by | |
| 7 the Free Software Foundation; either version 2, or (at your option) | |
| 8 any later version. | |
| 9 | |
| 10 This program is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 13 GNU General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU General Public License | |
| 16 along with this program; if not, write to the Free Software Foundation, | |
| 17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | |
| 18 | |
| 19 #ifdef HAVE_CONFIG_H | |
| 20 # include <config.h> | |
| 21 #endif | |
| 22 | |
| 23 /* Specification. */ | |
| 24 #include "strcasestr.h" | |
| 25 | |
| 26 #include <ctype.h> | |
|
6164
83bee8e13391
Include a header, to define NULL.
Bruno Haible <bruno@clisp.org>
parents:
6064
diff
changeset
|
27 #include <stddef.h> /* for NULL */ |
| 6058 | 28 |
| 29 #if HAVE_MBRTOWC | |
| 30 # include "mbuiter.h" | |
| 31 #endif | |
| 32 | |
| 33 #define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch)) | |
| 34 | |
| 35 /* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive | |
| 36 comparison. | |
| 37 Note: This function may, in multibyte locales, return success even if | |
| 38 strlen (haystack) < strlen (needle) ! */ | |
| 39 char * | |
| 40 strcasestr (const char *haystack, const char *needle) | |
| 41 { | |
| 42 /* Be careful not to look at the entire extent of haystack or needle | |
| 43 until needed. This is useful because of these two cases: | |
| 44 - haystack may be very long, and a match of needle found early, | |
| 45 - needle may be very long, and not even a short initial segment of | |
| 46 needle may be found in haystack. */ | |
| 47 #if HAVE_MBRTOWC | |
| 48 if (MB_CUR_MAX > 1) | |
| 49 { | |
| 50 mbui_iterator_t iter_needle; | |
| 51 | |
| 52 mbui_init (iter_needle, needle); | |
| 53 if (mbui_avail (iter_needle)) | |
| 54 { | |
| 55 mbchar_t b; | |
| 56 mbui_iterator_t iter_haystack; | |
| 57 | |
| 58 mb_copy (&b, &mbui_cur (iter_needle)); | |
| 59 if (b.wc_valid) | |
| 60 b.wc = towlower (b.wc); | |
| 61 | |
| 62 mbui_init (iter_haystack, haystack); | |
| 63 for (;; mbui_advance (iter_haystack)) | |
| 64 { | |
| 65 mbchar_t c; | |
| 66 | |
| 67 if (!mbui_avail (iter_haystack)) | |
| 68 /* No match. */ | |
| 69 return NULL; | |
| 70 | |
| 71 mb_copy (&c, &mbui_cur (iter_haystack)); | |
| 72 if (c.wc_valid) | |
| 73 c.wc = towlower (c.wc); | |
| 74 if (mb_equal (c, b)) | |
| 75 /* The first character matches. */ | |
| 76 { | |
| 77 mbui_iterator_t rhaystack; | |
| 78 mbui_iterator_t rneedle; | |
| 79 | |
| 80 memcpy (&rhaystack, &iter_haystack, sizeof (mbui_iterator_t)); | |
| 81 mbui_advance (rhaystack); | |
| 82 | |
| 83 mbui_init (rneedle, needle); | |
| 84 if (!mbui_avail (rneedle)) | |
| 85 abort (); | |
| 86 mbui_advance (rneedle); | |
| 87 | |
| 88 for (;; mbui_advance (rhaystack), mbui_advance (rneedle)) | |
| 89 { | |
| 90 if (!mbui_avail (rneedle)) | |
| 91 /* Found a match. */ | |
| 6064 | 92 return (char *) mbui_cur_ptr (iter_haystack); |
| 6058 | 93 if (!mbui_avail (rhaystack)) |
| 94 /* No match. */ | |
| 95 return NULL; | |
| 96 if (!mb_caseequal (mbui_cur (rhaystack), | |
| 97 mbui_cur (rneedle))) | |
| 98 /* Nothing in this round. */ | |
| 99 break; | |
| 100 } | |
| 101 } | |
| 102 } | |
| 103 } | |
| 104 else | |
| 105 return (char *) haystack; | |
| 106 } | |
| 107 else | |
| 108 #endif | |
| 109 { | |
| 110 if (*needle != '\0') | |
| 111 { | |
| 112 /* Speed up the following searches of needle by caching its first | |
| 113 character. */ | |
| 114 unsigned char b = TOLOWER ((unsigned char) *needle); | |
| 115 | |
| 116 needle++; | |
| 117 for (;; haystack++) | |
| 118 { | |
| 119 if (*haystack == '\0') | |
| 120 /* No match. */ | |
| 121 return NULL; | |
| 122 if (TOLOWER ((unsigned char) *haystack) == b) | |
| 123 /* The first character matches. */ | |
| 124 { | |
| 125 const char *rhaystack = haystack + 1; | |
| 126 const char *rneedle = needle; | |
| 127 | |
| 128 for (;; rhaystack++, rneedle++) | |
| 129 { | |
| 130 if (*rneedle == '\0') | |
| 131 /* Found a match. */ | |
| 132 return (char *) haystack; | |
| 133 if (*rhaystack == '\0') | |
| 134 /* No match. */ | |
| 135 return NULL; | |
| 136 if (TOLOWER ((unsigned char) *rhaystack) | |
| 137 != TOLOWER ((unsigned char) *rneedle)) | |
| 138 /* Nothing in this round. */ | |
| 139 break; | |
| 140 } | |
| 141 } | |
| 142 } | |
| 143 } | |
| 144 else | |
| 145 return (char *) haystack; | |
| 146 } | |
| 147 } |