| /* |
| FUNCTION |
| <<strcasestr>>---case-insensitive character string search |
| |
| INDEX |
| strcasestr |
| |
| ANSI_SYNOPSIS |
| #include <string.h> |
| char *strcasestr(const char *<[s]>, const char *<[find]>); |
| |
| TRAD_SYNOPSIS |
| #include <string.h> |
| int strcasecmp(<[s]>, <[find]>) |
| char *<[s]>; |
| char *<[find]>; |
| |
| DESCRIPTION |
| <<strcasestr>> searchs the string <[s]> for |
| the first occurrence of the sequence <[find]>. <<strcasestr>> |
| is identical to <<strstr>> except the search is |
| case-insensitive. |
| |
| RETURNS |
| |
| A pointer to the first case-insensitive occurrence of the sequence |
| <[find]> or <<NULL>> if no match was found. |
| |
| PORTABILITY |
| <<strcasestr>> is in the Berkeley Software Distribution. |
| |
| <<strcasestr>> requires no supporting OS subroutines. It uses |
| tolower() from elsewhere in this library. |
| |
| QUICKREF |
| strcasestr |
| */ |
| |
| /*- |
| * Copyright (c) 1990, 1993 |
| * The Regents of the University of California. All rights reserved. |
| * |
| * The quadratic 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. |
| * 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. |
| */ |
| /* Linear algorithm Copyright (C) 2008 Eric Blake |
| * Permission to use, copy, modify, and distribute the linear portion of |
| * software is freely granted, provided that this notice is preserved. |
| */ |
| |
| #include <sys/cdefs.h> |
| |
| #include <ctype.h> |
| #include <string.h> |
| #include <strings.h> |
| |
| #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) |
| # define RETURN_TYPE char * |
| # define AVAILABLE(h, h_l, j, n_l) \ |
| (!memchr ((h) + (h_l), '\0', (j) + (n_l) - (h_l)) \ |
| && ((h_l) = (j) + (n_l))) |
| # define CANON_ELEMENT(c) tolower (c) |
| # define CMP_FUNC strncasecmp |
| # include "str-two-way.h" |
| #endif |
| |
| /* |
| * Find the first occurrence of find in s, ignore case. |
| */ |
| char * |
| strcasestr(s, find) |
| const char *s, *find; |
| { |
| #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) |
| |
| /* Less code size, but quadratic performance in the worst case. */ |
| char c, sc; |
| size_t len; |
| |
| if ((c = *find++) != 0) { |
| c = tolower((unsigned char)c); |
| len = strlen(find); |
| do { |
| do { |
| if ((sc = *s++) == 0) |
| return (NULL); |
| } while ((char)tolower((unsigned char)sc) != c); |
| } while (strncasecmp(s, find, len) != 0); |
| s--; |
| } |
| return ((char *)s); |
| |
| #else /* compilation for speed */ |
| |
| /* Larger code size, but guaranteed linear performance. */ |
| const char *haystack = s; |
| const char *needle = find; |
| size_t needle_len; /* Length of NEEDLE. */ |
| size_t haystack_len; /* Known minimum length of HAYSTACK. */ |
| int ok = 1; /* True if NEEDLE is prefix of HAYSTACK. */ |
| |
| /* Determine length of NEEDLE, and in the process, make sure |
| HAYSTACK is at least as long (no point processing all of a long |
| NEEDLE if HAYSTACK is too short). */ |
| while (*haystack && *needle) |
| ok &= (tolower ((unsigned char) *haystack++) |
| == tolower ((unsigned char) *needle++)); |
| if (*needle) |
| return NULL; |
| if (ok) |
| return (char *) s; |
| needle_len = needle - find; |
| haystack = s + 1; |
| haystack_len = needle_len - 1; |
| |
| /* Perform the search. */ |
| if (needle_len < LONG_NEEDLE_THRESHOLD) |
| return two_way_short_needle ((const unsigned char *) haystack, |
| haystack_len, |
| (const unsigned char *) find, needle_len); |
| return two_way_long_needle ((const unsigned char *) haystack, haystack_len, |
| (const unsigned char *) find, needle_len); |
| #endif /* compilation for speed */ |
| } |