busybox/coreutils/cksum.c

/* vi: set sw=4 ts=4: */
/*
 * cksum - calculate the CRC32 checksum of a file
 *
 * Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */
#include "libbb.h"

int cksum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int cksum_main(int argc UNUSED_PARAM, char **argv)
{
	uint32_t *crc32_table = crc32_filltable(NULL, 1);
	uint32_t crc;
	off_t length, filesize;
	int bytes_read;
	int exit_code = EXIT_SUCCESS;
	uint8_t *cp;

#if ENABLE_DESKTOP
	getopt32(argv, ""); /* coreutils 6.9 compat */
	argv += optind;
#else
	argv++;
#endif

	do {
		int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input);

		if (fd < 0) {
			exit_code = EXIT_FAILURE;
			continue;
		}
		crc = 0;
		length = 0;

#define read_buf bb_common_bufsiz1
		while ((bytes_read = safe_read(fd, read_buf, sizeof(read_buf))) > 0) {
			cp = (uint8_t *) read_buf;
			length += bytes_read;
			do {
				crc = (crc << 8) ^ crc32_table[(crc >> 24) ^ *cp++];
			} while (--bytes_read);
		}
		close(fd);

		filesize = length;

		while (length) {
			crc = (crc << 8) ^ crc32_table[(uint8_t)(crc >> 24) ^ (uint8_t)length];
			/* must ensure that shift is unsigned! */
			if (sizeof(length) <= sizeof(unsigned))
				length = (unsigned)length >> 8;
			else if (sizeof(length) <= sizeof(unsigned long))
				length = (unsigned long)length >> 8;
			else
				length = (unsigned long long)length >> 8;
		}
		crc = ~crc;

		printf((*argv ? "%"PRIu32" %"OFF_FMT"i %s\n" : "%"PRIu32" %"OFF_FMT"i\n"),
				crc, filesize, *argv);
	} while (*argv && *++argv);

	fflush_stdout_and_exit(exit_code);
}
1	niro	532	/* vi: set sw=4 ts=4: */
2			/*
3			* cksum - calculate the CRC32 checksum of a file
4			*
5			* Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
6			*
7	niro	984	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8			*/
9	niro	816	#include "libbb.h"
10	niro	532
11	niro	816	int cksum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
12			int cksum_main(int argc UNUSED_PARAM, char **argv)
13	niro	532	{
14	niro	816	uint32_t *crc32_table = crc32_filltable(NULL, 1);
15	niro	532	uint32_t crc;
16	niro	816	off_t length, filesize;
17	niro	532	int bytes_read;
18	niro	984	int exit_code = EXIT_SUCCESS;
19	niro	816	uint8_t *cp;
20	niro	532
21	niro	816	#if ENABLE_DESKTOP
22			getopt32(argv, ""); /* coreutils 6.9 compat */
23			argv += optind;
24			#else
25			argv++;
26			#endif
27	niro	532
28			do {
29	niro	816	int fd = open_or_warn_stdin(argv ? argv : bb_msg_standard_input);
30	niro	532
31	niro	984	if (fd < 0) {
32			exit_code = EXIT_FAILURE;
33	niro	816	continue;
34	niro	984	}
35	niro	532	crc = 0;
36			length = 0;
37
38	niro	816	#define read_buf bb_common_bufsiz1
39			while ((bytes_read = safe_read(fd, read_buf, sizeof(read_buf))) > 0) {
40			cp = (uint8_t *) read_buf;
41	niro	532	length += bytes_read;
42	niro	816	do {
43			crc = (crc << 8) ^ crc32_table[(crc >> 24) ^ *cp++];
44			} while (--bytes_read);
45	niro	532	}
46	niro	816	close(fd);
47	niro	532
48			filesize = length;
49
50	niro	816	while (length) {
51			crc = (crc << 8) ^ crc32_table[(uint8_t)(crc >> 24) ^ (uint8_t)length];
52			/* must ensure that shift is unsigned! */
53			if (sizeof(length) <= sizeof(unsigned))
54			length = (unsigned)length >> 8;
55			else if (sizeof(length) <= sizeof(unsigned long))
56			length = (unsigned long)length >> 8;
57			else
58			length = (unsigned long long)length >> 8;
59	niro	532	}
60	niro	816	crc = ~crc;
61	niro	532
62	niro	816	printf((*argv ? "%"PRIu32" %"OFF_FMT"i %s\n" : "%"PRIu32" %"OFF_FMT"i\n"),
63			crc, filesize, *argv);
64			} while (argv && ++argv);
65	niro	532
66	niro	984	fflush_stdout_and_exit(exit_code);
67	niro	532	}