xref: /dragonfly/usr.bin/colrm/colrm.c (revision 1de703da)
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  * $FreeBSD: src/usr.bin/colrm/colrm.c,v 1.7.2.1 2001/08/02 01:33:29 obrien Exp $
34  * $DragonFly: src/usr.bin/colrm/colrm.c,v 1.2 2003/06/17 04:29:25 dillon Exp $
35  *
36  * @(#) Copyright (c) 1991, 1993 The Regents of the University of California.  All rights reserved.
37  * @(#)colrm.c	8.2 (Berkeley) 5/4/95
38  */
39 
40 #include <sys/types.h>
41 #include <limits.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #define	TAB	8
50 
51 int main __P((int, char *[]));
52 void check __P((FILE *));
53 static void usage __P((void));
54 
55 int
56 main(argc, argv)
57 	int argc;
58 	char *argv[];
59 {
60 	register u_long column, start, stop;
61 	register int ch;
62 	char *p;
63 
64 	while ((ch = getopt(argc, argv, "")) != -1)
65 		switch(ch) {
66 		case '?':
67 		default:
68 			usage();
69 		}
70 	argc -= optind;
71 	argv += optind;
72 
73 	start = stop = 0;
74 	switch(argc) {
75 	case 2:
76 		stop = strtol(argv[1], &p, 10);
77 		if (stop <= 0 || *p)
78 			errx(1, "illegal column -- %s", argv[1]);
79 		/* FALLTHROUGH */
80 	case 1:
81 		start = strtol(argv[0], &p, 10);
82 		if (start <= 0 || *p)
83 			errx(1, "illegal column -- %s", argv[0]);
84 		break;
85 	case 0:
86 		break;
87 	default:
88 		usage();
89 	}
90 
91 	if (stop && start > stop)
92 		errx(1, "illegal start and stop columns");
93 
94 	for (column = 0;;) {
95 		switch (ch = getchar()) {
96 		case EOF:
97 			check(stdin);
98 			break;
99 		case '\b':
100 			if (column)
101 				--column;
102 			break;
103 		case '\n':
104 			column = 0;
105 			break;
106 		case '\t':
107 			column = (column + TAB) & ~(TAB - 1);
108 			break;
109 		default:
110 			++column;
111 			break;
112 		}
113 
114 		if ((!start || column < start || (stop && column > stop)) &&
115 		    putchar(ch) == EOF)
116 			check(stdout);
117 	}
118 }
119 
120 void
121 check(stream)
122 	FILE *stream;
123 {
124 	if (feof(stream))
125 		exit(0);
126 	if (ferror(stream))
127 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
128 }
129 
130 void
131 usage()
132 {
133 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
134 	exit(1);
135 }
136 
137