# HG changeset patch
# User Bruno Haible <bruno@clisp.org>
# Date 1129056636 0
# Node ID 74a5018452c0ed53d24990e424a2aefe23313f98
# Parent  dbf2af5391cdaeeec29ca10be7ad74d39c2593e8
New module 'c-strcasestr'.

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2005-10-11  Bruno Haible  <bruno@clisp.org>
+
+	* modules/c-strcasestr: New file.
+	* MODULES.html.sh (String handling <string.h>): Add c-strcasestr.
+
 2005-10-11  Bruno Haible  <bruno@clisp.org>
 
 	* modules/c-strcase: New file.
diff --git a/MODULES.html.sh b/MODULES.html.sh
--- a/MODULES.html.sh
+++ b/MODULES.html.sh
@@ -1528,6 +1528,7 @@
   func_module stpncpy
   func_module c-strcase
   func_module strcase
+  func_module c-strcasestr
   func_module strcasestr
   func_module strchrnul
   func_module strdup
diff --git a/lib/ChangeLog b/lib/ChangeLog
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,8 @@
+2005-10-11  Bruno Haible  <bruno@clisp.org>
+
+	* c-strcasestr.h: New file, from GNU gettext.
+	* c-strcasestr.c: New file, from GNU gettext.
+
 2005-10-11  Bruno Haible  <bruno@clisp.org>
 
 	* c-strcase.h: New file, from GNU gettext.
diff --git a/lib/c-strcasestr.c b/lib/c-strcasestr.c
new file mode 100644
--- /dev/null
+++ b/lib/c-strcasestr.c
@@ -0,0 +1,78 @@
+/* c-strcasestr.c -- case insensitive substring search in C locale
+   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 "c-strcasestr.h"
+
+#include <stddef.h>
+
+#include "c-ctype.h"
+
+/* 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 *
+c_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 (*needle != '\0')
+    {
+      /* Speed up the following searches of needle by caching its first
+	 character.  */
+      unsigned char b = c_tolower ((unsigned char) *needle);
+
+      needle++;
+      for (;; haystack++)
+	{
+	  if (*haystack == '\0')
+	    /* No match.  */
+	    return NULL;
+	  if (c_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 (c_tolower ((unsigned char) *rhaystack)
+		      != c_tolower ((unsigned char) *rneedle))
+		    /* Nothing in this round.  */
+		    break;
+		}
+	    }
+	}
+    }
+  else
+    return (char *) haystack;
+}
diff --git a/lib/c-strcasestr.h b/lib/c-strcasestr.h
new file mode 100644
--- /dev/null
+++ b/lib/c-strcasestr.h
@@ -0,0 +1,37 @@
+/* Case-insensitive searching in a string in C locale.
+   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.  */
+
+#ifndef C_STRCASESTR_H
+#define C_STRCASESTR_H
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
+   comparison.  */
+extern char *c_strcasestr (const char *haystack, const char *needle);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* C_STRCASESTR_H */
diff --git a/modules/c-strcasestr b/modules/c-strcasestr
new file mode 100644
--- /dev/null
+++ b/modules/c-strcasestr
@@ -0,0 +1,24 @@
+Description:
+Case-insensitive searching in a string in C locale.
+
+Files:
+lib/c-strcasestr.h
+lib/c-strcasestr.c
+
+Depends-on:
+c-ctype
+
+configure.ac:
+
+Makefile.am:
+lib_SOURCES += c-strcasestr.h c-strcasestr.c
+
+Include:
+"c-strcasestr.h"
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
+