1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * uniq implementation for busybox
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4 | *
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5 | * Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
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6 | *
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7 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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8 | */
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9 |
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10 | /* BB_AUDIT SUSv3 compliant */
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11 | /* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
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12 |
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13 | //usage:#define uniq_trivial_usage
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14 | //usage: "[-cdu][-f,s,w N] [INPUT [OUTPUT]]"
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15 | //usage:#define uniq_full_usage "\n\n"
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16 | //usage: "Discard duplicate lines\n"
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17 | //usage: "\n -c Prefix lines by the number of occurrences"
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18 | //usage: "\n -d Only print duplicate lines"
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19 | //usage: "\n -u Only print unique lines"
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20 | //usage: "\n -f N Skip first N fields"
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21 | //usage: "\n -s N Skip first N chars (after any skipped fields)"
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22 | //usage: "\n -w N Compare N characters in line"
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23 | //usage:
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24 | //usage:#define uniq_example_usage
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25 | //usage: "$ echo -e \"a\\na\\nb\\nc\\nc\\na\" | sort | uniq\n"
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26 | //usage: "a\n"
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27 | //usage: "b\n"
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28 | //usage: "c\n"
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29 |
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30 | #include "libbb.h"
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31 |
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32 | int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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33 | int uniq_main(int argc UNUSED_PARAM, char **argv)
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34 | {
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35 | const char *input_filename;
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36 | unsigned skip_fields, skip_chars, max_chars;
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37 | unsigned opt;
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38 | char *cur_line;
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39 | const char *cur_compare;
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40 |
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41 | enum {
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42 | OPT_c = 0x1,
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43 | OPT_d = 0x2, /* print only dups */
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44 | OPT_u = 0x4, /* print only uniq */
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45 | OPT_f = 0x8,
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46 | OPT_s = 0x10,
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47 | OPT_w = 0x20,
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48 | };
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49 |
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50 | skip_fields = skip_chars = 0;
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51 | max_chars = INT_MAX;
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52 |
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53 | opt_complementary = "f+:s+:w+";
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54 | opt = getopt32(argv, "cduf:s:w:", &skip_fields, &skip_chars, &max_chars);
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55 | argv += optind;
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56 |
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57 | input_filename = argv[0];
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58 | if (input_filename) {
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59 | const char *output;
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60 |
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61 | if (input_filename[0] != '-' || input_filename[1]) {
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62 | close(STDIN_FILENO); /* == 0 */
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63 | xopen(input_filename, O_RDONLY); /* fd will be 0 */
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64 | }
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65 | output = argv[1];
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66 | if (output) {
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67 | if (argv[2])
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68 | bb_show_usage();
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69 | if (output[0] != '-' || output[1]) {
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70 | // Won't work with "uniq - FILE" and closed stdin:
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71 | //close(STDOUT_FILENO);
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72 | //xopen(output, O_WRONLY | O_CREAT | O_TRUNC);
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73 | xmove_fd(xopen(output, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
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74 | }
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75 | }
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76 | }
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77 |
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78 | cur_compare = cur_line = NULL; /* prime the pump */
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79 |
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80 | do {
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81 | unsigned i;
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82 | unsigned long dups;
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83 | char *old_line;
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84 | const char *old_compare;
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85 |
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86 | old_line = cur_line;
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87 | old_compare = cur_compare;
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88 | dups = 0;
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89 |
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90 | /* gnu uniq ignores newlines */
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91 | while ((cur_line = xmalloc_fgetline(stdin)) != NULL) {
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92 | cur_compare = cur_line;
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93 | for (i = skip_fields; i; i--) {
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94 | cur_compare = skip_whitespace(cur_compare);
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95 | cur_compare = skip_non_whitespace(cur_compare);
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96 | }
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97 | for (i = skip_chars; *cur_compare && i; i--) {
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98 | ++cur_compare;
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99 | }
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100 |
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101 | if (!old_line || strncmp(old_compare, cur_compare, max_chars)) {
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102 | break;
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103 | }
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104 |
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105 | free(cur_line);
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106 | ++dups; /* testing for overflow seems excessive */
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107 | }
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108 |
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109 | if (old_line) {
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110 | if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_u) */
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111 | if (opt & OPT_c) {
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112 | /* %7lu matches GNU coreutils 6.9 */
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113 | printf("%7lu ", dups + 1);
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114 | }
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115 | printf("%s\n", old_line);
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116 | }
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117 | free(old_line);
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118 | }
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119 | } while (cur_line);
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120 |
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121 | die_if_ferror(stdin, input_filename);
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122 |
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123 | fflush_stdout_and_exit(EXIT_SUCCESS);
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124 | }
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