diff options
author | mike <mike@FreeBSD.org> | 2001-10-09 01:29:56 +0000 |
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committer | mike <mike@FreeBSD.org> | 2001-10-09 01:29:56 +0000 |
commit | 9a27a4f0fe38f10e63129f3c8a66f7518bcec44d (patch) | |
tree | e211e48c706a6cba3be5da1192f50a34f20109a8 /lib/libc/string/strnstr.c | |
parent | 5c6420034e70959dbac169b4709905cd37b3ec5f (diff) | |
download | FreeBSD-src-9a27a4f0fe38f10e63129f3c8a66f7518bcec44d.zip FreeBSD-src-9a27a4f0fe38f10e63129f3c8a66f7518bcec44d.tar.gz |
Add a new libc function, strnstr(3), which allows one to limit the
number of characters that are searched. This is especially useful
with file operations and non-NUL terminated strings.
Silence from: -audit, -hackers
MFC after: 5 days
Diffstat (limited to 'lib/libc/string/strnstr.c')
-rw-r--r-- | lib/libc/string/strnstr.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/lib/libc/string/strnstr.c b/lib/libc/string/strnstr.c new file mode 100644 index 0000000..98c0103 --- /dev/null +++ b/lib/libc/string/strnstr.c @@ -0,0 +1,70 @@ +/*- + * Copyright (c) 2001 Mike Barcroft <mike@FreeBSD.org> + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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> +__RCSID("@(#)strstr.c 8.1 (Berkeley) 6/4/93"); +__FBSDID("$FreeBSD$"); + +#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(s, find, slen) + 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 ((sc = *s++) == '\0' || slen-- < 1) + return (NULL); + } while (sc != c); + if (len > slen) + return (NULL); + } while (strncmp(s, find, len) != 0); + s--; + } + return ((char *)s); +} |