1 /* vi: set sw=4 ts=4: */
3 * cksum - calculate the CRC32 checksum of a file
5 * Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */
15 int cksum_main(int argc, char **argv) {
17 uint32_t *crc32_table = bb_crc32_filltable(1);
21 long length, filesize;
24 RESERVE_CONFIG_BUFFER(buf, BUFSIZ);
25 int inp_stdin = (argc == optind) ? 1 : 0;
28 fp = bb_wfopen_input((inp_stdin) ? bb_msg_standard_input : *++argv);
33 while ((bytes_read = fread(buf, 1, BUFSIZ, fp)) > 0) {
37 crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ (*cp++)) & 0xffL];
42 for (; length; length >>= 8)
43 crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xffL];
47 printf("%"PRIu32" %li\n", crc, filesize);
51 printf("%"PRIu32" %li %s\n", crc, filesize, *argv);