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\n"
32 "Discard all but one of successive identical lines from INPUT\n"
33 "(or standard input), writing to OUTPUT (or standard output).\n";
35 /* max chars in line */
38 typedef void (Print) (FILE *, const char *);
40 typedef int (Decide) (const char *, const char *);
42 /* container for two lines to be compared */
52 /* set up all the variables of a uniq operation */
53 static Subject *subject_init(Subject * self, FILE * in, FILE * out,
65 /* point a and b to the appropriate lines;
66 * count the recurrences (if any) of a string;
68 static Subject *subject_next(Subject * self)
70 /* tmp line holders */
71 static char line[2][UNIQ_MAX];
72 static int alternator = 0;
74 if (fgets(line[alternator], UNIQ_MAX, self->in)) {
76 self->b = line[alternator];
84 static Subject *subject_last(Subject * self)
91 static Subject *subject_study(Subject * self)
93 if (self->a == NULL) {
96 if (self->b == NULL) {
97 fprintf(self->out, "%s", self->a);
100 if (strcmp(self->a, self->b) == 0) {
103 fprintf(self->out, "%s", self->a);
104 self->recurrence = 0;
110 set_file_pointers(int schema, FILE ** in, FILE ** out, char **argv)
118 *in = fopen(argv[0], "r");
122 *in = fopen(argv[0], "r");
123 *out = fopen(argv[1], "w");
127 fprintf(stderr, "uniq: %s: %s\n", argv[0], strerror(errno));
131 fprintf(stderr, "uniq: %s: %s\n", argv[1], strerror(errno));
138 /* one variable is the decision algo */
139 /* another variable is the printing algo */
141 /* I don't think I have to have more than a 1 line memory
142 this is the one constant */
144 /* it seems like GNU/uniq only takes one or two files as an option */
146 /* ________________________________________________________________________ */
147 int uniq_main(int argc, char **argv)
155 for (i = 1; i < argc; i++) {
156 if (argv[i][0] == '-') {
170 /* 0 src: stdin; dst: stdout */
171 /* 1 src: file; dst: stdout */
172 /* 2 src: file; dst: file */
173 if (set_file_pointers((argc - 1), &in, &out, &argv[i])) {
177 subject_init(&s, in, out, NULL);
178 while (subject_next(&s)) {
187 /* $Id: uniq.c,v 1.9 2000/04/17 16:16:10 erik Exp $ */