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 the GPL v2 or later, see the file LICENSE in this tarball.
8 */
9
10/* BB_AUDIT SUSv3 compliant */
11/* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
12
13#include "libbb.h"
14
15int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
16int uniq_main(int argc UNUSED_PARAM, char **argv)
17{
18	const char *input_filename;
19	unsigned skip_fields, skip_chars, max_chars;
20	unsigned opt;
21	char *cur_line;
22	const char *cur_compare;
23
24	enum {
25		OPT_c = 0x1,
26		OPT_d = 0x2, /* print only dups */
27		OPT_u = 0x4, /* print only uniq */
28		OPT_f = 0x8,
29		OPT_s = 0x10,
30		OPT_w = 0x20,
31	};
32
33	skip_fields = skip_chars = 0;
34	max_chars = INT_MAX;
35
36	opt_complementary = "f+:s+:w+";
37	opt = getopt32(argv, "cduf:s:w:", &skip_fields, &skip_chars, &max_chars);
38	argv += optind;
39
40	input_filename = argv[0];
41	if (input_filename) {
42		const char *output;
43
44		if (input_filename[0] != '-' || input_filename[1]) {
45			close(STDIN_FILENO); /* == 0 */
46			xopen(input_filename, O_RDONLY); /* fd will be 0 */
47		}
48		output = argv[1];
49		if (output) {
50			if (argv[2])
51				bb_show_usage();
52			if (output[0] != '-' || output[1]) {
53				// Won't work with "uniq - FILE" and closed stdin:
54				//close(STDOUT_FILENO);
55				//xopen3(output, O_WRONLY | O_CREAT | O_TRUNC, 0666);
56				xmove_fd(xopen3(output, O_WRONLY | O_CREAT | O_TRUNC, 0666), STDOUT_FILENO);
57			}
58		}
59	}
60
61	cur_compare = cur_line = NULL; /* prime the pump */
62
63	do {
64		unsigned i;
65		unsigned long dups;
66		char *old_line;
67		const char *old_compare;
68
69		old_line = cur_line;
70		old_compare = cur_compare;
71		dups = 0;
72
73		/* gnu uniq ignores newlines */
74		while ((cur_line = xmalloc_fgetline(stdin)) != NULL) {
75			cur_compare = cur_line;
76			for (i = skip_fields; i; i--) {
77				cur_compare = skip_whitespace(cur_compare);
78				cur_compare = skip_non_whitespace(cur_compare);
79			}
80			for (i = skip_chars; *cur_compare && i; i--) {
81				++cur_compare;
82			}
83
84			if (!old_line || strncmp(old_compare, cur_compare, max_chars)) {
85				break;
86			}
87
88			free(cur_line);
89			++dups;	 /* testing for overflow seems excessive */
90		}
91
92		if (old_line) {
93			if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_u) */
94				if (opt & OPT_c) {
95					/* %7lu matches GNU coreutils 6.9 */
96					printf("%7lu ", dups + 1);
97				}
98				printf("%s\n", old_line);
99			}
100			free(old_line);
101		}
102	} while (cur_line);
103
104	die_if_ferror(stdin, input_filename);
105
106	fflush_stdout_and_exit(EXIT_SUCCESS);
107}
108