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/* |
FUNCTION |
<<strcasestr>>---case-insensitive character string search |
|
INDEX |
strcasestr |
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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. |
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QUICKREF |
strcasestr |
*/ |
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/*- |
* 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> |
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#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 */ |
} |