[deliverable/linux.git] / Documentation / pcmcia / crc32hash.c

/* crc32hash.c - derived from linux/lib/crc32.c, GNU GPL v2 */
/* Usage example:
$ ./crc32hash "Dual Speed"
*/

#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>

static unsigned int crc32(unsigned char const *p, unsigned int len)
{
	int i;
	unsigned int crc = 0;
	while (len--) {
		crc ^= *p++;
		for (i = 0; i < 8; i++)
			crc = (crc >> 1) ^ ((crc & 1) ? 0xedb88320 : 0);
	}
	return crc;
}

int main(int argc, char **argv) {
	unsigned int result;
	if (argc != 2) {
		printf("no string passed as argument\n");
		return -1;
	}
	result = crc32((unsigned char const *)argv[1], strlen(argv[1]));
	printf("0x%x\n", result);
	return 0;
}
Commit	Line	Data
d29693bf RD	1	/* crc32hash.c - derived from linux/lib/crc32.c, GNU GPL v2 */
	2	/* Usage example:
	3	$ ./crc32hash "Dual Speed"
	4	*/
	5
	6	#include <string.h>
	7	#include <stdio.h>
	8	#include <ctype.h>
	9	#include <stdlib.h>
	10
b7ed698c	11	static unsigned int crc32(unsigned char const *p, unsigned int len)
d29693bf RD	12	{
	13	int i;
	14	unsigned int crc = 0;
	15	while (len--) {
	16	crc ^= *p++;
	17	for (i = 0; i < 8; i++)
	18	crc = (crc >> 1) ^ ((crc & 1) ? 0xedb88320 : 0);
	19	}
	20	return crc;
	21	}
	22
	23	int main(int argc, char **argv) {
	24	unsigned int result;
	25	if (argc != 2) {
	26	printf("no string passed as argument\n");
	27	return -1;
	28	}
ffab10ec	29	result = crc32((unsigned char const *)argv[1], strlen(argv[1]));
d29693bf RD	30	printf("0x%x\n", result);
	31	return 0;
	32	}