xref: /minix/usr.bin/colrm/colrm.c (revision 4483d188)
1 /*	$NetBSD: colrm.c,v 1.9 2011/08/30 21:35:09 joerg 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
40 static char sccsid[] = "@(#)colrm.c	8.2 (Berkeley) 5/4/95";
41 #endif
42 __RCSID("$NetBSD: colrm.c,v 1.9 2011/08/30 21:35:09 joerg 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 
57 static void	check(FILE *);
58 __dead static void	usage(void);
59 
60 int
main(int argc,char * argv[])61 main(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 
123 static void
check(FILE * stream)124 check(FILE *stream)
125 {
126 	if (feof(stream))
127 		exit(0);
128 	if (ferror(stream))
129 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
130 }
131 
132 static void
usage(void)133 usage(void)
134 {
135 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
136 	exit(1);
137 }
138