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[821] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * cksum - calculate the CRC32 checksum of a file
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| 4 | *
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| 5 | * Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
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[1765] | 6 | *
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[821] | 7 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */
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| 8 |
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[1765] | 9 | #include "libbb.h"
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[821] | 10 |
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[1765] | 11 | int cksum_main(int argc, char **argv);
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| 12 | int cksum_main(int argc, char **argv)
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| 13 | {
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| 14 | uint32_t *crc32_table = crc32_filltable(NULL, 1);
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[821] | 15 |
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| 16 | FILE *fp;
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| 17 | uint32_t crc;
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| 18 | long length, filesize;
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| 19 | int bytes_read;
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| 20 | char *cp;
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[1765] | 21 |
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[821] | 22 | int inp_stdin = (argc == optind) ? 1 : 0;
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[1765] | 23 |
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[821] | 24 | do {
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[1765] | 25 | fp = fopen_or_warn_stdin((inp_stdin) ? bb_msg_standard_input : *++argv);
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| 26 |
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[821] | 27 | crc = 0;
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| 28 | length = 0;
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[1765] | 29 |
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| 30 | #define read_buf bb_common_bufsiz1
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| 31 | while ((bytes_read = fread(read_buf, 1, BUFSIZ, fp)) > 0) {
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| 32 | cp = read_buf;
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[821] | 33 | length += bytes_read;
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| 34 | while (bytes_read--)
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| 35 | crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ (*cp++)) & 0xffL];
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| 36 | }
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[1765] | 37 |
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[821] | 38 | filesize = length;
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[1765] | 39 |
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[821] | 40 | for (; length; length >>= 8)
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| 41 | crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xffL];
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| 42 | crc ^= 0xffffffffL;
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| 43 |
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| 44 | if (inp_stdin) {
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[1765] | 45 | printf("%" PRIu32 " %li\n", crc, filesize);
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[821] | 46 | break;
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| 47 | }
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[1765] | 48 |
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| 49 | printf("%" PRIu32 " %li %s\n", crc, filesize, *argv);
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[821] | 50 | fclose(fp);
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[1765] | 51 | } while (*(argv + 1));
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| 52 |
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| 53 | fflush_stdout_and_exit(EXIT_SUCCESS);
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[821] | 54 | }
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