xref: /freebsd/usr.bin/colrm/colrm.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
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 
34 #ifndef lint
35 static char copyright[] =
36 "@(#) Copyright (c) 1991, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 static char sccsid[] = "@(#)colrm.c	8.1 (Berkeley) 6/6/93";
42 #endif /* not lint */
43 
44 #include <sys/types.h>
45 #include <limits.h>
46 #include <errno.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 
51 #define	TAB	8
52 
53 void err __P((const char *, ...));
54 void check __P((FILE *));
55 void usage __P((void));
56 
57 int
58 main(argc, argv)
59 	int argc;
60 	char *argv[];
61 {
62 	register u_long column, start, stop;
63 	register int ch;
64 	char *p;
65 
66 	while ((ch = getopt(argc, argv, "")) != EOF)
67 		switch(ch) {
68 		case '?':
69 		default:
70 			usage();
71 		}
72 	argc -= optind;
73 	argv += optind;
74 
75 	start = stop = 0;
76 	switch(argc) {
77 	case 2:
78 		stop = strtol(argv[1], &p, 10);
79 		if (stop <= 0 || *p)
80 			err("illegal column -- %s", argv[1]);
81 		/* FALLTHROUGH */
82 	case 1:
83 		start = strtol(argv[0], &p, 10);
84 		if (start <= 0 || *p)
85 			err("illegal column -- %s", argv[0]);
86 		break;
87 	case 0:
88 		break;
89 	default:
90 		usage();
91 	}
92 
93 	if (stop && start > stop)
94 		err("illegal start and stop columns");
95 
96 	for (column = 0;;) {
97 		switch (ch = getchar()) {
98 		case EOF:
99 			check(stdin);
100 			break;
101 		case '\b':
102 			if (column)
103 				--column;
104 			break;
105 		case '\n':
106 			column = 0;
107 			break;
108 		case '\t':
109 			column = (column + TAB) & ~(TAB - 1);
110 			break;
111 		default:
112 			++column;
113 			break;
114 		}
115 
116 		if ((!start || column < start || stop && column > stop) &&
117 		    putchar(ch) == EOF)
118 			check(stdout);
119 	}
120 }
121 
122 void
123 check(stream)
124 	FILE *stream;
125 {
126 	if (feof(stream))
127 		exit(0);
128 	if (ferror(stream))
129 		err("%s: %s",
130 		    stream == stdin ? "stdin" : "stdout", strerror(errno));
131 }
132 
133 void
134 usage()
135 {
136 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
137 	exit(1);
138 }
139 
140 #if __STDC__
141 #include <stdarg.h>
142 #else
143 #include <varargs.h>
144 #endif
145 
146 void
147 #if __STDC__
148 err(const char *fmt, ...)
149 #else
150 err(fmt, va_alist)
151 	char *fmt;
152         va_dcl
153 #endif
154 {
155 	va_list ap;
156 #if __STDC__
157 	va_start(ap, fmt);
158 #else
159 	va_start(ap);
160 #endif
161 	(void)fprintf(stderr, "colrm: ");
162 	(void)vfprintf(stderr, fmt, ap);
163 	va_end(ap);
164 	(void)fprintf(stderr, "\n");
165 	exit(1);
166 	/* NOTREACHED */
167 }
168