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.
13 //config: uniq is used to remove duplicate lines from a sorted file.
15 //applet:IF_UNIQ(APPLET(uniq, BB_DIR_USR_BIN, BB_SUID_DROP))
17 //kbuild:lib-$(CONFIG_UNIQ) += uniq.o
19 /* BB_AUDIT SUSv3 compliant */
20 /* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
22 //usage:#define uniq_trivial_usage
23 //usage: "[-cdu][-f,s,w N] [INPUT [OUTPUT]]"
24 //usage:#define uniq_full_usage "\n\n"
25 //usage: "Discard duplicate lines\n"
26 //usage: "\n -c Prefix lines by the number of occurrences"
27 //usage: "\n -d Only print duplicate lines"
28 //usage: "\n -u Only print unique lines"
29 //usage: "\n -f N Skip first N fields"
30 //usage: "\n -s N Skip first N chars (after any skipped fields)"
31 //usage: "\n -w N Compare N characters in line"
33 //usage:#define uniq_example_usage
34 //usage: "$ echo -e \"a\\na\\nb\\nc\\nc\\na\" | sort | uniq\n"
41 int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
42 int uniq_main(int argc UNUSED_PARAM, char **argv)
44 const char *input_filename;
45 unsigned skip_fields, skip_chars, max_chars;
48 const char *cur_compare;
52 OPT_d = 0x2, /* print only dups */
53 OPT_u = 0x4, /* print only uniq */
60 skip_fields = skip_chars = 0;
63 opt = getopt32(argv, "cduf:+s:+w:+i", &skip_fields, &skip_chars, &max_chars);
66 input_filename = argv[0];
70 if (input_filename[0] != '-' || input_filename[1]) {
71 close(STDIN_FILENO); /* == 0 */
72 xopen(input_filename, O_RDONLY); /* fd will be 0 */
78 if (output[0] != '-' || output[1]) {
79 // Won't work with "uniq - FILE" and closed stdin:
80 //close(STDOUT_FILENO);
81 //xopen(output, O_WRONLY | O_CREAT | O_TRUNC);
82 xmove_fd(xopen(output, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
87 cur_compare = cur_line = NULL; /* prime the pump */
93 const char *old_compare;
96 old_compare = cur_compare;
99 /* gnu uniq ignores newlines */
100 while ((cur_line = xmalloc_fgetline(stdin)) != NULL) {
101 cur_compare = cur_line;
102 for (i = skip_fields; i; i--) {
103 cur_compare = skip_whitespace(cur_compare);
104 cur_compare = skip_non_whitespace(cur_compare);
106 for (i = skip_chars; *cur_compare && i; i--) {
113 ? strncasecmp(old_compare, cur_compare, max_chars)
114 : strncmp(old_compare, cur_compare, max_chars)
120 ++dups; /* testing for overflow seems excessive */
124 if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_u) */
126 /* %7lu matches GNU coreutils 6.9 */
127 printf("%7lu ", dups + 1);
135 die_if_ferror(stdin, input_filename);
137 fflush_stdout_and_exit(EXIT_SUCCESS);