[src/trunk]: src/lib/libc/string add strnstr.c from FreeBSD

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2504f8eda6fb
branches:  trunk
changeset: 332500:2504f8eda6fb
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Sep 24 22:21:33 2014 +0000

description:
add strnstr.c from FreeBSD

diffstat:

 lib/libc/string/strnstr.c |  71 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 71 insertions(+), 0 deletions(-)

diffs (75 lines):

diff -r cf7bb3cb9053 -r 2504f8eda6fb lib/libc/string/strnstr.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libc/string/strnstr.c Wed Sep 24 22:21:33 2014 +0000
@@ -0,0 +1,71 @@
+/*     $NetBSD: strnstr.c,v 1.1 2014/09/24 22:21:33 christos Exp $     */
+
+/*-
+ * Copyright (c) 2001 Mike Barcroft <mike%FreeBSD.org@localhost>
+ * Copyright (c) 1990, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)strstr.c   8.1 (Berkeley) 6/4/93";
+#else
+__RCSID("$NetBSD: strnstr.c,v 1.1 2014/09/24 22:21:33 christos Exp $");
+#endif
+#endif /* LIBC_SCCS and not lint */
+/* FreeBSD: head/lib/libc/string/strnstr.c 251069 2013-05-28 20:57:40Z emaste */
+
+#include <string.h>
+
+/*
+ * Find the first occurrence of find in s, where the search is limited to the
+ * first slen characters of s.
+ */
+char *
+strnstr(const char *s, const char *find, size_t slen)
+{
+       char c, sc;
+       size_t len;
+
+       if ((c = *find++) != '\0') {
+               len = strlen(find);
+               do {
+                       do {
+                               if (slen-- < 1 || (sc = *s++) == '\0')
+                                       return NULL;
+                       } while (sc != c);
+                       if (len > slen)
+                               return NULL;
+               } while (strncmp(s, find, len) != 0);
+               s--;
+       }
+       return __UNCONST(s);
+}