Rob Landley | 856489b | 2006-04-18 20:57:28 +0000 | [diff] [blame] | 1 | /* 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 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ |
| 8 | |
| 9 | #include <stdio.h> |
| 10 | #include <unistd.h> |
| 11 | #include <fcntl.h> |
Rob Landley | 856489b | 2006-04-18 20:57:28 +0000 | [diff] [blame] | 12 | #include "busybox.h" |
| 13 | |
| 14 | int cksum_main(int argc, char **argv) { |
| 15 | |
| 16 | uint32_t *crc32_table = bb_crc32_filltable(1); |
| 17 | |
| 18 | FILE *fp; |
| 19 | uint32_t crc; |
| 20 | long length, filesize; |
| 21 | int bytes_read; |
| 22 | char *cp; |
| 23 | RESERVE_CONFIG_BUFFER(buf, BUFSIZ); |
| 24 | int inp_stdin = (argc == optind) ? 1 : 0; |
| 25 | |
| 26 | do { |
| 27 | fp = bb_wfopen_input((inp_stdin) ? bb_msg_standard_input : *++argv); |
| 28 | |
| 29 | crc = 0; |
| 30 | length = 0; |
| 31 | |
| 32 | while ((bytes_read = fread(buf, 1, BUFSIZ, fp)) > 0) { |
| 33 | cp = buf; |
| 34 | length += bytes_read; |
| 35 | while (bytes_read--) |
| 36 | crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ (*cp++)) & 0xffL]; |
| 37 | } |
| 38 | |
| 39 | filesize = length; |
| 40 | |
| 41 | for (; length; length >>= 8) |
| 42 | crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xffL]; |
| 43 | crc ^= 0xffffffffL; |
| 44 | |
| 45 | if (inp_stdin) { |
| 46 | printf("%"PRIu32" %li\n", crc, filesize); |
| 47 | break; |
| 48 | } |
| 49 | |
| 50 | printf("%"PRIu32" %li %s\n", crc, filesize, *argv); |
| 51 | fclose(fp); |
| 52 | } while (*(argv+1)); |
| 53 | |
| 54 | return EXIT_SUCCESS; |
| 55 | } |