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 "config.h"
13#include <stdio.h>
14#include <stdlib.h>
15#include <stdint.h>
16#include <string.h>
17#include <unistd.h>
18#ifdef HAVE_GETOPT_H
19#include <getopt.h>
20#endif
21#include <fcntl.h>
22
23#include "et/com_err.h"
24#include "ss/ss.h"
25#include "ext2fs/ext2fs.h"
26
27
28int main(int argc, char **argv)
29{
30	int		c;
31	uint32_t	crc = ~0;
32	uint32_t	(*csum_func)(uint32_t crc, unsigned char const *p,
33				     size_t len);
34	FILE		*f;
35
36	csum_func = ext2fs_crc32c_le;
37
38	while ((c = getopt (argc, argv, "h")) != EOF) {
39		switch (c) {
40		case 'h':
41		default:
42			com_err(argv[0], 0, "Usage: crcsum [file]\n");
43			return 1;
44		}
45	}
46
47	if (optind == argc)
48		f = stdin;
49	else {
50		f = fopen(argv[optind], "r");
51		if (!f) {
52			com_err(argv[0], errno, "while trying to open %s\n",
53				argv[optind]);
54			exit(1);
55		}
56	}
57
58	while (!feof(f)) {
59		unsigned char buf[4096];
60
61		int c = fread(buf, 1, sizeof(buf), f);
62
63		if (c)
64			crc = csum_func(crc, buf, c);
65	}
66	printf("%u\n", crc);
67	return 0;
68}
69