colrm.c revision 87244 
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35
36__FBSDID("$FreeBSD: head/usr.bin/colrm/colrm.c 87244 2001-12-02 23:44:42Z markm $");
37
38#ifndef lint
39static const char copyright[] =
40"@(#) Copyright (c) 1991, 1993\n\
41	The Regents of the University of California.  All rights reserved.\n";
42#endif
43
44#ifndef lint
45static const char sccsid[] = "@(#)colrm.c	8.2 (Berkeley) 5/4/95";
46#endif
47
48#include <sys/types.h>
49#include <err.h>
50#include <errno.h>
51#include <limits.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <unistd.h>
56
57#define	TAB	8
58
59void check __P((FILE *));
60static void usage __P((void));
61
62int
63main(argc, argv)
64	int argc;
65	char *argv[];
66{
67	u_long column, start, stop;
68	int ch;
69	char *p;
70
71	while ((ch = getopt(argc, argv, "")) != -1)
72		switch(ch) {
73		case '?':
74		default:
75			usage();
76		}
77	argc -= optind;
78	argv += optind;
79
80	start = stop = 0;
81	switch(argc) {
82	case 2:
83		stop = strtol(argv[1], &p, 10);
84		if (stop <= 0 || *p)
85			errx(1, "illegal column -- %s", argv[1]);
86		/* FALLTHROUGH */
87	case 1:
88		start = strtol(argv[0], &p, 10);
89		if (start <= 0 || *p)
90			errx(1, "illegal column -- %s", argv[0]);
91		break;
92	case 0:
93		break;
94	default:
95		usage();
96	}
97
98	if (stop && start > stop)
99		errx(1, "illegal start and stop columns");
100
101	for (column = 0;;) {
102		switch (ch = getchar()) {
103		case EOF:
104			check(stdin);
105			break;
106		case '\b':
107			if (column)
108				--column;
109			break;
110		case '\n':
111			column = 0;
112			break;
113		case '\t':
114			column = (column + TAB) & ~(TAB - 1);
115			break;
116		default:
117			++column;
118			break;
119		}
120
121		if ((!start || column < start || (stop && column > stop)) &&
122		    putchar(ch) == EOF)
123			check(stdout);
124	}
125}
126
127void
128check(stream)
129	FILE *stream;
130{
131	if (feof(stream))
132		exit(0);
133	if (ferror(stream))
134		err(1, "%s", stream == stdin ? "stdin" : "stdout");
135}
136
137void
138usage()
139{
140	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
141	exit(1);
142}
143
144