xref: /PHP-5.5/ext/standard/crc32.c (revision 73c1be26)
1 /*
2    +----------------------------------------------------------------------+
3    | PHP Version 5                                                        |
4    +----------------------------------------------------------------------+
5    | Copyright (c) 1997-2015 The PHP Group                                |
6    +----------------------------------------------------------------------+
7    | This source file is subject to version 3.01 of the PHP license,      |
8    | that is bundled with this package in the file LICENSE, and is        |
9    | available through the world-wide-web at the following url:           |
10    | http://www.php.net/license/3_01.txt                                  |
11    | If you did not receive a copy of the PHP license and are unable to   |
12    | obtain it through the world-wide-web, please send a note to          |
13    | license@php.net so we can mail you a copy immediately.               |
14    +----------------------------------------------------------------------+
15    | Author: Rasmus Lerdorf <rasmus@php.net>                              |
16    +----------------------------------------------------------------------+
17 */
18 
19 /* $Id$ */
20 
21 #include "php.h"
22 #include "basic_functions.h"
23 #include "crc32.h"
24 
25 /* {{{ proto string crc32(string str)
26    Calculate the crc32 polynomial of a string */
PHP_NAMED_FUNCTION(php_if_crc32)27 PHP_NAMED_FUNCTION(php_if_crc32)
28 {
29 	char *p;
30 	int len, nr;
31 	php_uint32 crcinit = 0;
32 	register php_uint32 crc;
33 
34 	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &p, &nr) == FAILURE) {
35 		return;
36 	}
37 	crc = crcinit^0xFFFFFFFF;
38 
39 	for (len =+nr; nr--; ++p) {
40 		crc = ((crc >> 8) & 0x00FFFFFF) ^ crc32tab[(crc ^ (*p)) & 0xFF ];
41 	}
42 	RETVAL_LONG(crc^0xFFFFFFFF);
43 }
44 /* }}} */
45 
46 /*
47  * Local variables:
48  * tab-width: 4
49  * c-basic-offset: 4
50  * End:
51  * vim600: sw=4 ts=4 fdm=marker
52  * vim<600: sw=4 ts=4
53  */
54