xref: /netbsd/usr.bin/colrm/colrm.c (revision bf9ec67e)
1 /*	$NetBSD: colrm.c,v 1.5 1997/10/18 13:00:20 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)colrm.c	8.2 (Berkeley) 5/4/95";
45 #endif
46 __RCSID("$NetBSD: colrm.c,v 1.5 1997/10/18 13:00:20 lukem Exp $");
47 #endif /* not lint */
48 
49 #include <sys/types.h>
50 
51 #include <err.h>
52 #include <errno.h>
53 #include <limits.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 
59 #define	TAB	8
60 
61 void	check __P((FILE *));
62 int	main __P((int, char **));
63 void	usage __P((void));
64 
65 int
66 main(argc, argv)
67 	int argc;
68 	char *argv[];
69 {
70 	u_long column, start, stop;
71 	int ch;
72 	char *p;
73 
74 	while ((ch = getopt(argc, argv, "")) != -1)
75 		switch(ch) {
76 		case '?':
77 		default:
78 			usage();
79 		}
80 	argc -= optind;
81 	argv += optind;
82 
83 	start = stop = 0;
84 	switch(argc) {
85 	case 2:
86 		stop = strtol(argv[1], &p, 10);
87 		if (stop <= 0 || *p)
88 			errx(1, "illegal column -- %s", argv[1]);
89 		/* FALLTHROUGH */
90 	case 1:
91 		start = strtol(argv[0], &p, 10);
92 		if (start <= 0 || *p)
93 			errx(1, "illegal column -- %s", argv[0]);
94 		break;
95 	case 0:
96 		break;
97 	default:
98 		usage();
99 	}
100 
101 	if (stop && start > stop)
102 		err(1, "illegal start and stop columns");
103 
104 	for (column = 0;;) {
105 		switch (ch = getchar()) {
106 		case EOF:
107 			check(stdin);
108 			break;
109 		case '\b':
110 			if (column)
111 				--column;
112 			break;
113 		case '\n':
114 			column = 0;
115 			break;
116 		case '\t':
117 			column = (column + TAB) & ~(TAB - 1);
118 			break;
119 		default:
120 			++column;
121 			break;
122 		}
123 
124 		if ((!start || column < start || (stop && column > stop)) &&
125 		    putchar(ch) == EOF)
126 			check(stdout);
127 	}
128 }
129 
130 void
131 check(stream)
132 	FILE *stream;
133 {
134 	if (feof(stream))
135 		exit(0);
136 	if (ferror(stream))
137 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
138 }
139 
140 void
141 usage()
142 {
143 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
144 	exit(1);
145 }
146