1 files changed, 56 insertions, 0 deletions
diff --git a/sysdeps/generic/strstr.c b/sysdeps/generic/strstr.c
new file mode 100644
index 0000000000..06681de931
--- /dev/null
+++ b/sysdeps/generic/strstr.c
@@ -0,0 +1,56 @@
+/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <stddef.h>
+#include <string.h>
+
+/* Return the first ocurrence of NEEDLE in HAYSTACK.  */
+char *
+DEFUN(strstr, (haystack, needle),
+      CONST char *CONST haystack AND
+      CONST char *CONST needle)
+{
+  register CONST char *CONST needle_end = strchr(needle, '\0');
+  register CONST char *CONST haystack_end = strchr(haystack, '\0');
+  register CONST size_t needle_len = needle_end - needle;
+  register CONST size_t needle_last = needle_len - 1;
+  register CONST char *begin;
+
+  if (needle_len == 0)
+    return (char *) haystack;	/* ANSI 4.11.5.7, line 25.  */
+  if ((size_t) (haystack_end - haystack) < needle_len)
+    return NULL;
+
+  for (begin = &haystack[needle_last]; begin < haystack_end; ++begin)
+    {
+      register CONST char *n = &needle[needle_last];
+      register CONST char *h = begin;
+
+      do
+	if (*h != *n)
+	  goto loop;		/* continue for loop */
+      while (--n >= needle && --h >= haystack);
+
+      return (char *) h;
+
+    loop:;
+    }
+
+  return NULL;
+}