source: branches/3.2/mindi-busybox/coreutils/uniq.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
File size: 3.1 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * uniq implementation for busybox
4 *
5 * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9
10/* BB_AUDIT SUSv3 compliant */
11/* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
12
13//usage:#define uniq_trivial_usage
14//usage:       "[-cdu][-f,s,w N] [INPUT [OUTPUT]]"
15//usage:#define uniq_full_usage "\n\n"
16//usage:       "Discard duplicate lines\n"
17//usage:     "\n    -c  Prefix lines by the number of occurrences"
18//usage:     "\n    -d  Only print duplicate lines"
19//usage:     "\n    -u  Only print unique lines"
20//usage:     "\n    -f N    Skip first N fields"
21//usage:     "\n    -s N    Skip first N chars (after any skipped fields)"
22//usage:     "\n    -w N    Compare N characters in line"
23//usage:
24//usage:#define uniq_example_usage
25//usage:       "$ echo -e \"a\\na\\nb\\nc\\nc\\na\" | sort | uniq\n"
26//usage:       "a\n"
27//usage:       "b\n"
28//usage:       "c\n"
29
30#include "libbb.h"
31
32int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
33int uniq_main(int argc UNUSED_PARAM, char **argv)
34{
35    const char *input_filename;
36    unsigned skip_fields, skip_chars, max_chars;
37    unsigned opt;
38    char *cur_line;
39    const char *cur_compare;
40
41    enum {
42        OPT_c = 0x1,
43        OPT_d = 0x2, /* print only dups */
44        OPT_u = 0x4, /* print only uniq */
45        OPT_f = 0x8,
46        OPT_s = 0x10,
47        OPT_w = 0x20,
48    };
49
50    skip_fields = skip_chars = 0;
51    max_chars = INT_MAX;
52
53    opt_complementary = "f+:s+:w+";
54    opt = getopt32(argv, "cduf:s:w:", &skip_fields, &skip_chars, &max_chars);
55    argv += optind;
56
57    input_filename = argv[0];
58    if (input_filename) {
59        const char *output;
60
61        if (input_filename[0] != '-' || input_filename[1]) {
62            close(STDIN_FILENO); /* == 0 */
63            xopen(input_filename, O_RDONLY); /* fd will be 0 */
64        }
65        output = argv[1];
66        if (output) {
67            if (argv[2])
68                bb_show_usage();
69            if (output[0] != '-' || output[1]) {
70                // Won't work with "uniq - FILE" and closed stdin:
71                //close(STDOUT_FILENO);
72                //xopen(output, O_WRONLY | O_CREAT | O_TRUNC);
73                xmove_fd(xopen(output, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
74            }
75        }
76    }
77
78    cur_compare = cur_line = NULL; /* prime the pump */
79
80    do {
81        unsigned i;
82        unsigned long dups;
83        char *old_line;
84        const char *old_compare;
85
86        old_line = cur_line;
87        old_compare = cur_compare;
88        dups = 0;
89
90        /* gnu uniq ignores newlines */
91        while ((cur_line = xmalloc_fgetline(stdin)) != NULL) {
92            cur_compare = cur_line;
93            for (i = skip_fields; i; i--) {
94                cur_compare = skip_whitespace(cur_compare);
95                cur_compare = skip_non_whitespace(cur_compare);
96            }
97            for (i = skip_chars; *cur_compare && i; i--) {
98                ++cur_compare;
99            }
100
101            if (!old_line || strncmp(old_compare, cur_compare, max_chars)) {
102                break;
103            }
104
105            free(cur_line);
106            ++dups;  /* testing for overflow seems excessive */
107        }
108
109        if (old_line) {
110            if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_u) */
111                if (opt & OPT_c) {
112                    /* %7lu matches GNU coreutils 6.9 */
113                    printf("%7lu ", dups + 1);
114                }
115                printf("%s\n", old_line);
116            }
117            free(old_line);
118        }
119    } while (cur_line);
120
121    die_if_ferror(stdin, input_filename);
122
123    fflush_stdout_and_exit(EXIT_SUCCESS);
124}
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