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 "Discard all but one of successive identical lines from INPUT (or\n"
33 "standard input), writing to OUTPUT (or standard output).\n"
35 "\t-h\tdisplay this help and exit\n"
38 "A field is a run of whitespace, then non-whitespace characters.\n"
39 "Fields are skipped before chars.\n";
41 /* max chars in line */
44 typedef void (Print) (FILE *, const char *);
46 typedef int (Decide) (const char *, const char *);
48 /* container for two lines to be compared */
58 /* set up all the variables of a uniq operation */
59 static Subject *subject_init(Subject * self, FILE * in, FILE * out,
71 /* point a and b to the appropriate lines;
72 * count the recurrences (if any) of a string;
74 static Subject *subject_next(Subject * self)
76 /* tmp line holders */
77 static char line[2][UNIQ_MAX];
78 static int alternator = 0;
80 if (fgets(line[alternator], UNIQ_MAX, self->in)) {
82 self->b = line[alternator];
90 static Subject *subject_last(Subject * self)
97 static Subject *subject_study(Subject * self)
99 if (self->a == NULL) {
102 if (self->b == NULL) {
103 fprintf(self->out, "%s", self->a);
106 if (strcmp(self->a, self->b) == 0) {
109 fprintf(self->out, "%s", self->a);
110 self->recurrence = 0;
116 set_file_pointers(int schema, FILE ** in, FILE ** out, char **argv)
124 *in = fopen(argv[0], "r");
128 *in = fopen(argv[0], "r");
129 *out = fopen(argv[1], "w");
133 fprintf(stderr, "uniq: %s: %s\n", argv[0], strerror(errno));
137 fprintf(stderr, "uniq: %s: %s\n", argv[1], strerror(errno));
144 /* one variable is the decision algo */
145 /* another variable is the printing algo */
147 /* I don't think I have to have more than a 1 line memory
148 this is the one constant */
150 /* it seems like GNU/uniq only takes one or two files as an option */
152 /* ________________________________________________________________________ */
153 int uniq_main(int argc, char **argv)
161 for (i = 1; i < argc; i++) {
162 if (argv[i][0] == '-') {
176 /* 0 src: stdin; dst: stdout */
177 /* 1 src: file; dst: stdout */
178 /* 2 src: file; dst: file */
179 if (set_file_pointers((argc - 1), &in, &out, &argv[i])) {
183 subject_init(&s, in, out, NULL);
184 while (subject_next(&s)) {
193 /* $Id: uniq.c,v 1.8 2000/04/13 01:18:56 erik Exp $ */