1 /* vi: set sw=4 ts=4: */
3 * uniq implementation for busybox
5 * Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 /* BB_AUDIT SUSv3 compliant */
11 /* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
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"
18 //usage: "\n -c Prefix lines by the number of occurrences"
19 //usage: "\n -d Only print duplicate lines"
20 //usage: "\n -u Only print unique lines"
21 //usage: "\n -f N Skip first N fields"
22 //usage: "\n -s N Skip first N chars (after any skipped fields)"
23 //usage: "\n -w N Compare N characters in line"
25 //usage:#define uniq_example_usage
26 //usage: "$ echo -e \"a\\na\\nb\\nc\\nc\\na\" | sort | uniq\n"
33 int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
34 int uniq_main(int argc UNUSED_PARAM, char **argv)
36 const char *input_filename;
37 unsigned skip_fields, skip_chars, max_chars;
40 const char *cur_compare;
44 OPT_d = 0x2, /* print only dups */
45 OPT_u = 0x4, /* print only uniq */
51 skip_fields = skip_chars = 0;
54 opt_complementary = "f+:s+:w+";
55 opt = getopt32(argv, "cduf:s:w:", &skip_fields, &skip_chars, &max_chars);
58 input_filename = argv[0];
62 if (input_filename[0] != '-' || input_filename[1]) {
63 close(STDIN_FILENO); /* == 0 */
64 xopen(input_filename, O_RDONLY); /* fd will be 0 */
70 if (output[0] != '-' || output[1]) {
71 // Won't work with "uniq - FILE" and closed stdin:
72 //close(STDOUT_FILENO);
73 //xopen(output, O_WRONLY | O_CREAT | O_TRUNC);
74 xmove_fd(xopen(output, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
79 cur_compare = cur_line = NULL; /* prime the pump */
85 const char *old_compare;
88 old_compare = cur_compare;
91 /* gnu uniq ignores newlines */
92 while ((cur_line = xmalloc_fgetline(stdin)) != NULL) {
93 cur_compare = cur_line;
94 for (i = skip_fields; i; i--) {
95 cur_compare = skip_whitespace(cur_compare);
96 cur_compare = skip_non_whitespace(cur_compare);
98 for (i = skip_chars; *cur_compare && i; i--) {
102 if (!old_line || strncmp(old_compare, cur_compare, max_chars)) {
107 ++dups; /* testing for overflow seems excessive */
111 if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_u) */
113 /* %7lu matches GNU coreutils 6.9 */
114 printf("%7lu ", dups + 1);
116 printf("%s\n", old_line);
122 die_if_ferror(stdin, input_filename);
124 fflush_stdout_and_exit(EXIT_SUCCESS);