1 /* vi: set sw=4 ts=4: */
3 * Mini uniq implementation for busybox
6 * Copyright (C) 1999,2000 by Lineo, inc.
7 * Written by John Beppu <beppu@lineo.com>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
30 static const char uniq_usage[] =
31 "uniq [OPTION]... [INPUT [OUTPUT]]\n"
32 #ifndef BB_FEATURE_TRIVIAL_HELP
33 "\nDiscard all but one of successive identical lines from INPUT\n"
34 "(or standard input), writing to OUTPUT (or standard output).\n"
38 /* max chars in line */
41 typedef void (Print) (FILE *, const char *);
43 typedef int (Decide) (const char *, const char *);
45 /* container for two lines to be compared */
55 /* set up all the variables of a uniq operation */
56 static Subject *subject_init(Subject * self, FILE * in, FILE * out,
68 /* point a and b to the appropriate lines;
69 * count the recurrences (if any) of a string;
71 static Subject *subject_next(Subject * self)
73 /* tmp line holders */
74 static char line[2][UNIQ_MAX];
75 static int alternator = 0;
77 if (fgets(line[alternator], UNIQ_MAX, self->in)) {
79 self->b = line[alternator];
87 static Subject *subject_last(Subject * self)
94 static Subject *subject_study(Subject * self)
96 if (self->a == NULL) {
99 if (self->b == NULL) {
100 fprintf(self->out, "%s", self->a);
103 if (strcmp(self->a, self->b) == 0) {
106 fprintf(self->out, "%s", self->a);
107 self->recurrence = 0;
113 set_file_pointers(int schema, FILE ** in, FILE ** out, char **argv)
121 *in = fopen(argv[0], "r");
125 *in = fopen(argv[0], "r");
126 *out = fopen(argv[1], "w");
130 fprintf(stderr, "uniq: %s: %s\n", argv[0], strerror(errno));
134 fprintf(stderr, "uniq: %s: %s\n", argv[1], strerror(errno));
141 /* one variable is the decision algo */
142 /* another variable is the printing algo */
144 /* I don't think I have to have more than a 1 line memory
145 this is the one constant */
147 /* it seems like GNU/uniq only takes one or two files as an option */
149 /* ________________________________________________________________________ */
150 int uniq_main(int argc, char **argv)
158 for (i = 1; i < argc; i++) {
159 if (argv[i][0] == '-') {
173 /* 0 src: stdin; dst: stdout */
174 /* 1 src: file; dst: stdout */
175 /* 2 src: file; dst: file */
176 if (set_file_pointers((argc - 1), &in, &out, &argv[i])) {
180 subject_init(&s, in, out, NULL);
181 while (subject_next(&s)) {
190 /* $Id: uniq.c,v 1.11 2000/06/19 17:25:40 andersen Exp $ */