--- /dev/null
+/* Case-insensitive searching in a string.
+ Copyright (C) 2005 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2005.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ 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
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+/* Specification. */
+#include "strcasestr.h"
+
+#include <ctype.h>
+
+#if HAVE_MBRTOWC
+# include "mbuiter.h"
+#endif
+
+#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
+
+/* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
+ comparison.
+ Note: This function may, in multibyte locales, return success even if
+ strlen (haystack) < strlen (needle) ! */
+char *
+strcasestr (const char *haystack, const char *needle)
+{
+ /* Be careful not to look at the entire extent of haystack or needle
+ until needed. This is useful because of these two cases:
+ - haystack may be very long, and a match of needle found early,
+ - needle may be very long, and not even a short initial segment of
+ needle may be found in haystack. */
+#if HAVE_MBRTOWC
+ if (MB_CUR_MAX > 1)
+ {
+ mbui_iterator_t iter_needle;
+
+ mbui_init (iter_needle, needle);
+ if (mbui_avail (iter_needle))
+ {
+ mbchar_t b;
+ mbui_iterator_t iter_haystack;
+
+ mb_copy (&b, &mbui_cur (iter_needle));
+ if (b.wc_valid)
+ b.wc = towlower (b.wc);
+
+ mbui_init (iter_haystack, haystack);
+ for (;; mbui_advance (iter_haystack))
+ {
+ mbchar_t c;
+
+ if (!mbui_avail (iter_haystack))
+ /* No match. */
+ return NULL;
+
+ mb_copy (&c, &mbui_cur (iter_haystack));
+ if (c.wc_valid)
+ c.wc = towlower (c.wc);
+ if (mb_equal (c, b))
+ /* The first character matches. */
+ {
+ mbui_iterator_t rhaystack;
+ mbui_iterator_t rneedle;
+
+ memcpy (&rhaystack, &iter_haystack, sizeof (mbui_iterator_t));
+ mbui_advance (rhaystack);
+
+ mbui_init (rneedle, needle);
+ if (!mbui_avail (rneedle))
+ abort ();
+ mbui_advance (rneedle);
+
+ for (;; mbui_advance (rhaystack), mbui_advance (rneedle))
+ {
+ if (!mbui_avail (rneedle))
+ /* Found a match. */
+ return (char *) haystack;
+ if (!mbui_avail (rhaystack))
+ /* No match. */
+ return NULL;
+ if (!mb_caseequal (mbui_cur (rhaystack),
+ mbui_cur (rneedle)))
+ /* Nothing in this round. */
+ break;
+ }
+ }
+ }
+ }
+ else
+ return (char *) haystack;
+ }
+ else
+#endif
+ {
+ if (*needle != '\0')
+ {
+ /* Speed up the following searches of needle by caching its first
+ character. */
+ unsigned char b = TOLOWER ((unsigned char) *needle);
+
+ needle++;
+ for (;; haystack++)
+ {
+ if (*haystack == '\0')
+ /* No match. */
+ return NULL;
+ if (TOLOWER ((unsigned char) *haystack) == b)
+ /* The first character matches. */
+ {
+ const char *rhaystack = haystack + 1;
+ const char *rneedle = needle;
+
+ for (;; rhaystack++, rneedle++)
+ {
+ if (*rneedle == '\0')
+ /* Found a match. */
+ return (char *) haystack;
+ if (*rhaystack == '\0')
+ /* No match. */
+ return NULL;
+ if (TOLOWER ((unsigned char) *rhaystack)
+ != TOLOWER ((unsigned char) *rneedle))
+ /* Nothing in this round. */
+ break;
+ }
+ }
+ }
+ }
+ else
+ return (char *) haystack;
+ }
+}
--- /dev/null
+/* Case-insensitive searching in a string.
+ Copyright (C) 2005 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ 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
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
+ comparison.
+ Note: This function may, in multibyte locales, return success even if
+ strlen (haystack) < strlen (needle) ! */
+extern char *strcasestr (const char *haystack, const char *needle);
+
+#ifdef __cplusplus
+}
+#endif
--- /dev/null
+# strcasestr.m4 serial 1
+dnl Copyright (C) 2005 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_STRCASESTR],
+[
+ dnl No known system has a strcasestr() function that works correctly in
+ dnl multibyte locales. Therefore we use our version always.
+ AC_LIBOBJ(strcasestr)
+ AC_DEFINE(strcasestr, rpl_strcasestr, [Define to rpl_strcasestr always.])
+ gl_PREREQ_STRCASESTR
+])
+
+# Prerequisites of lib/strcasestr.c.
+AC_DEFUN([gl_PREREQ_STRCASESTR], [
+ gl_FUNC_MBRTOWC
+])