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/* 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, char **argv)
{
uint32_t *crc32_table = crc32_filltable(NULL, 1);
FILE *fp;
uint32_t crc;
long length, filesize;
int bytes_read;
char *cp;
int inp_stdin = (argc == optind) ? 1 : 0;
do {
fp = fopen_or_warn_stdin((inp_stdin) ? bb_msg_standard_input : *++argv);
crc = 0;
length = 0;
#define read_buf bb_common_bufsiz1
while ((bytes_read = fread(read_buf, 1, BUFSIZ, fp)) > 0) {
cp = read_buf;
length += bytes_read;
while (bytes_read--)
crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ (*cp++)) & 0xffL];
}
filesize = length;
for (; length; length >>= 8)
crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xffL];
crc ^= 0xffffffffL;
if (inp_stdin) {
printf("%" PRIu32 " %li\n", crc, filesize);
break;
}
printf("%" PRIu32 " %li %s\n", crc, filesize, *argv);
fclose(fp);
} while (*(argv + 1));
fflush_stdout_and_exit(EXIT_SUCCESS);
}
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