1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * sum -- checksum and count the blocks in a file
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4 | * Like BSD sum or SysV sum -r, except like SysV sum if -s option is given.
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5 | *
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6 | * Copyright (C) 86, 89, 91, 1995-2002, 2004 Free Software Foundation, Inc.
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7 | * Copyright (C) 2005 by Erik Andersen <andersen@codepoet.org>
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8 | * Copyright (C) 2005 by Mike Frysinger <vapier@gentoo.org>
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9 | *
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10 | * Written by Kayvan Aghaiepour and David MacKenzie
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11 | * Taken from coreutils and turned into a busybox applet by Mike Frysinger
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12 | *
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13 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
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14 | */
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15 |
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16 | #include "libbb.h"
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17 |
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18 | enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
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19 |
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20 | /* BSD: calculate and print the rotated checksum and the size in 1K blocks
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21 | The checksum varies depending on sizeof (int). */
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22 | /* SYSV: calculate and print the checksum and the size in 512-byte blocks */
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23 | /* Return 1 if successful. */
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24 | static unsigned sum_file(const char *file, const unsigned type)
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25 | {
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26 | #define buf bb_common_bufsiz1
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27 | uintmax_t total_bytes = 0;
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28 | int fd = 0, r;
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29 |
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30 | /* The sum of all the input bytes, modulo (UINT_MAX + 1). */
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31 | unsigned s = 0;
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32 |
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33 | if (NOT_LONE_DASH(file)) {
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34 | fd = open(file, O_RDONLY);
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35 | if (fd == -1)
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36 | goto ret_bad;
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37 | }
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38 |
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39 | while (1) {
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40 | size_t bytes_read = safe_read(fd, buf, BUFSIZ);
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41 |
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42 | if ((ssize_t)bytes_read <= 0) {
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43 | r = (fd && close(fd) != 0);
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44 | if (!bytes_read && !r)
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45 | /* no error */
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46 | break;
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47 | ret_bad:
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48 | bb_perror_msg(file);
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49 | return 0;
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50 | }
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51 |
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52 | total_bytes += bytes_read;
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53 | if (type >= SUM_SYSV) {
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54 | do s += buf[--bytes_read]; while (bytes_read);
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55 | } else {
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56 | r = 0;
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57 | do {
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58 | s = (s >> 1) + ((s & 1) << 15);
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59 | s += buf[r++];
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60 | s &= 0xffff; /* Keep it within bounds. */
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61 | } while (--bytes_read);
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62 | }
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63 | }
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64 |
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65 | if (type < PRINT_NAME)
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66 | file = "";
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67 | if (type >= SUM_SYSV) {
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68 | r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
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69 | s = (r & 0xffff) + (r >> 16);
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70 | printf("%d %ju %s\n", s, (total_bytes+511)/512, file);
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71 | } else
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72 | printf("%05d %5ju %s\n", s, (total_bytes+1023)/1024, file);
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73 | return 1;
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74 | #undef buf
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75 | }
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76 |
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77 | int sum_main(int argc, char **argv);
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78 | int sum_main(int argc, char **argv)
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79 | {
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80 | unsigned n;
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81 | unsigned type = SUM_BSD;
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82 |
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83 | n = getopt32(argv, "sr");
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84 | if (n & 1) type = SUM_SYSV;
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85 | /* give the bsd priority over sysv func */
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86 | if (n & 2) type = SUM_BSD;
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87 |
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88 | if (argc == optind) {
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89 | /* Do not print the name */
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90 | n = sum_file("-", type);
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91 | } else {
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92 | /* Need to print the name if either
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93 | - more than one file given
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94 | - doing sysv */
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95 | type += argc - 1 > optind || type == SUM_SYSV;
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96 | for (n = 1; optind < argc; optind++)
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97 | n &= sum_file(argv[optind], type);
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98 | }
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99 | return !n;
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100 | }
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