| | 1 | /*- |
| | 2 | * Copyright (c) 2005 Pascal Gloor <pascal.gloor@spale.com> |
| | 3 | * |
| | 4 | * Redistribution and use in source and binary forms, with or without |
| | 5 | * modification, are permitted provided that the following conditions |
| | 6 | * are met: |
| | 7 | * 1. Redistributions of source code must retain the above copyright |
| | 8 | * notice, this list of conditions and the following disclaimer. |
| | 9 | * 2. Redistributions in binary form must reproduce the above copyright |
| | 10 | * notice, this list of conditions and the following disclaimer in the |
| | 11 | * documentation and/or other materials provided with the distribution. |
| | 12 | * 3. The name of the author may not be used to endorse or promote |
| | 13 | * products derived from this software without specific prior written |
| | 14 | * permission. |
| | 15 | * |
| | 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| | 17 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| | 18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| | 19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| | 20 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| | 21 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| | 22 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| | 23 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| | 24 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| | 25 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| | 26 | * SUCH DAMAGE. |
| | 27 | */ |
| | 28 | |
| | 29 | #include <sys/cdefs.h> |
| | 30 | __FBSDID("$FreeBSD: src/lib/libc/string/memmem.c,v 1.2 2009/02/03 17:58:20 danger Exp $"); |
| | 31 | |
| | 32 | #include <string.h> |
| | 33 | |
| | 34 | /* |
| | 35 | * Find the first occurrence of the byte string s in byte string l. |
| | 36 | */ |
| | 37 | |
| | 38 | void * |
| | 39 | memmem(const void *l, size_t l_len, const void *s, size_t s_len) |
| | 40 | { |
| | 41 | register char *cur, *last; |
| | 42 | const char *cl = (const char *)l; |
| | 43 | const char *cs = (const char *)s; |
| | 44 | |
| | 45 | /* we need something to compare */ |
| | 46 | if (l_len == 0 || s_len == 0) |
| | 47 | return NULL; |
| | 48 | |
| | 49 | /* "s" must be smaller or equal to "l" */ |
| | 50 | if (l_len < s_len) |
| | 51 | return NULL; |
| | 52 | |
| | 53 | /* special case where s_len == 1 */ |
| | 54 | if (s_len == 1) |
| | 55 | return memchr(l, (int)*cs, l_len); |
| | 56 | |
| | 57 | /* the last position where its possible to find "s" in "l" */ |
| | 58 | last = (char *)cl + l_len - s_len; |
| | 59 | |
| | 60 | for (cur = (char *)cl; cur <= last; cur++) |
| | 61 | if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0) |
| | 62 | return cur; |
| | 63 | |
| | 64 | return NULL; |
| | 65 | } |
projects / apple / libc.git / blame_incremental