1 /*	$OpenBSD: colrm.c,v 1.8 2003/06/10 22:20:45 deraadt Exp $	*/
2 /*	$NetBSD: colrm.c,v 1.4 1995/09/02 05:51:37 jtc Exp $	*/
3 
4 /*-
5  * Copyright (c) 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static char copyright[] =
35 "@(#) Copyright (c) 1991, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)colrm.c	8.2 (Berkeley) 5/4/95";
42 #endif
43 static char rcsid[] = "$OpenBSD: colrm.c,v 1.8 2003/06/10 22:20:45 deraadt Exp $";
44 #endif /* not lint */
45 
46 #include <sys/types.h>
47 
48 #include <err.h>
49 #include <errno.h>
50 #include <limits.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 
56 #define	TAB	8
57 
58 void check(FILE *);
59 void usage(void);
60 
61 int
main(int argc,char * argv[])62 main(int argc, char *argv[])
63 {
64 	u_long column, start, stop;
65 	int ch;
66 	char *p;
67 
68 	while ((ch = getopt(argc, argv, "")) != -1)
69 		switch(ch) {
70 		case '?':
71 		default:
72 			usage();
73 		}
74 	argc -= optind;
75 	argv += optind;
76 
77 	start = stop = 0;
78 	switch(argc) {
79 	case 2:
80 		stop = strtol(argv[1], &p, 10);
81 		if (stop <= 0 || *p)
82 			errx(1, "illegal column -- %s", argv[1]);
83 		/* FALLTHROUGH */
84 	case 1:
85 		start = strtol(argv[0], &p, 10);
86 		if (start <= 0 || *p)
87 			errx(1, "illegal column -- %s", argv[0]);
88 		break;
89 	case 0:
90 		break;
91 	default:
92 		usage();
93 	}
94 
95 	if (stop && start > stop)
96 		err(1, "illegal start and stop columns");
97 
98 	for (column = 0;;) {
99 		switch (ch = getchar()) {
100 		case EOF:
101 			check(stdin);
102 			break;
103 		case '\b':
104 			if (column)
105 				--column;
106 			break;
107 		case '\n':
108 			column = 0;
109 			break;
110 		case '\t':
111 			column = (column + TAB) & ~(TAB - 1);
112 			break;
113 		default:
114 			++column;
115 			break;
116 		}
117 
118 		if ((!start || column < start || (stop && column > stop)) &&
119 		    putchar(ch) == EOF)
120 			check(stdout);
121 	}
122 }
123 
124 void
check(FILE * stream)125 check(FILE *stream)
126 {
127 	if (feof(stream))
128 		exit(0);
129 	if (ferror(stream))
130 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
131 }
132 
133 void
usage(void)134 usage(void)
135 {
136 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
137 	exit(1);
138 }
139