1 /*
2 * crcsum.c
3 *
4 * Copyright (C) 2013 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Public
8 * License.
9 * %End-Header%
10 */
11
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <stdint.h>
15 #include <string.h>
16 #include <unistd.h>
17 #ifdef HAVE_GETOPT_H
18 #include <getopt.h>
19 #endif
20 #include <fcntl.h>
21
22 #include "et/com_err.h"
23 #include "ss/ss.h"
24 #include "ext2fs/ext2fs.h"
25
26
main(int argc,char ** argv)27 int main(int argc, char **argv)
28 {
29 int c;
30 uint32_t crc = ~0;
31 uint32_t (*csum_func)(uint32_t crc, unsigned char const *p,
32 size_t len);
33 FILE *f;
34
35 csum_func = ext2fs_crc32c_le;
36
37 while ((c = getopt (argc, argv, "h")) != EOF) {
38 switch (c) {
39 case 'h':
40 default:
41 com_err(argv[0], 0, "Usage: crcsum [file]\n");
42 return 1;
43 }
44 }
45
46 if (optind == argc)
47 f = stdin;
48 else {
49 f = fopen(argv[optind], "r");
50 if (!f) {
51 com_err(argv[0], errno, "while trying to open %s\n",
52 argv[optind]);
53 exit(1);
54 }
55 }
56
57 while (!feof(f)) {
58 unsigned char buf[4096];
59
60 int c = fread(buf, 1, sizeof(buf), f);
61
62 if (c)
63 crc = csum_func(crc, buf, c);
64 }
65 printf("%u\n", crc);
66 return 0;
67 }
68