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 11 static unsigned int crc32(unsigned char const *p, unsigned int len) 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 } 29 result = crc32((unsigned char const *)argv[1], strlen(argv[1])); 30 printf("0x%x\n", result); 31 return 0; 32 } 33