1/*	$NetBSD: colrm.c,v 1.8 2008/07/21 14:19:21 lukem Exp $	*/
2
3/*-
4 * Copyright (c) 1991, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34__COPYRIGHT("@(#) Copyright (c) 1991, 1993\
35 The Regents of the University of California.  All rights reserved.");
36#endif /* not lint */
37
38#ifndef lint
39#if 0
40static char sccsid[] = "@(#)colrm.c	8.2 (Berkeley) 5/4/95";
41#endif
42__RCSID("$NetBSD: colrm.c,v 1.8 2008/07/21 14:19:21 lukem Exp $");
43#endif /* not lint */
44
45#include <sys/types.h>
46
47#include <err.h>
48#include <errno.h>
49#include <limits.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <unistd.h>
54
55#define	TAB	8
56
57static void	check(FILE *);
58__dead static void	usage(void);
59
60int
61main(int argc, char *argv[])
62{
63	u_long column, start, stop;
64	int ch;
65	char *p;
66
67	while ((ch = getopt(argc, argv, "")) != -1)
68		switch(ch) {
69		case '?':
70		default:
71			usage();
72		}
73	argc -= optind;
74	argv += optind;
75
76	start = stop = 0;
77	switch(argc) {
78	case 2:
79		stop = strtol(argv[1], &p, 10);
80		if (stop <= 0 || *p)
81			errx(1, "illegal column -- %s", argv[1]);
82		/* FALLTHROUGH */
83	case 1:
84		start = strtol(argv[0], &p, 10);
85		if (start <= 0 || *p)
86			errx(1, "illegal column -- %s", argv[0]);
87		break;
88	case 0:
89		break;
90	default:
91		usage();
92	}
93
94	if (stop && start > stop)
95		err(1, "illegal start and stop columns");
96
97	for (column = 0;;) {
98		switch (ch = getchar()) {
99		case EOF:
100			check(stdin);
101			break;
102		case '\b':
103			if (column)
104				--column;
105			break;
106		case '\n':
107			column = 0;
108			break;
109		case '\t':
110			column = (column + TAB) & ~(TAB - 1);
111			break;
112		default:
113			++column;
114			break;
115		}
116
117		if ((!start || column < start || (stop && column > stop)) &&
118		    putchar(ch) == EOF)
119			check(stdout);
120	}
121}
122
123static void
124check(FILE *stream)
125{
126	if (feof(stream))
127		exit(0);
128	if (ferror(stream))
129		err(1, "%s", stream == stdin ? "stdin" : "stdout");
130}
131
132static void
133usage(void)
134{
135	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
136	exit(1);
137}
138