petidomo/libtext/find_string.c
2000-12-13 15:45:25 +00:00

91 lines
2.8 KiB
C

/*
* $Source$
* $Revision$
* $Date$
*
* Copyright (c) 1996-99 by Peter Simons <simons@cys.de>
* All rights reserved.
*
* 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 Peter Simons.
*
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <string.h>
#include "text.h"
/* A simple text search.
This function performs a simple, case-independent text search in
the indicated buffer.
RETURNS: FindString() returns a pointer to the first occurance of
"string" in "buffer", or NULL, if the string was not found.
NOTE: This routine will perform poorly on larger text buffers.
AUTHOR: Peter Simons <simons@rhein.de>
*/
char *
text_find_string(char * buffer, /* text buffer */
char * string /* string to find */
)
{
int buffer_len;
int string_len;
char * result;
/* Sanity checks. */
assert(buffer != NULL);
assert(string != NULL);
if (!buffer || !string)
return NULL;
buffer_len = strlen(buffer);
string_len = strlen(string);
if (buffer_len == 0 || buffer_len < string_len)
return NULL;
if (string_len == 0)
return buffer;
/* Now look for the string. */
for(result = NULL; buffer_len >= string_len; buffer++, buffer_len--) {
if (!strncasecmp(buffer, string, string_len)) {
result = buffer;
break;
}
}
return result;
}