mirror of
https://github.com/sheumann/hush.git
synced 2024-12-27 01:32:08 +00:00
68 lines
1.6 KiB
C
68 lines
1.6 KiB
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);
|
|
}
|