xref: /freebsd/usr.bin/colrm/colrm.c (revision 1c8af8787354e20c2b38cab5801698133ff8b403)
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	8.2 (Berkeley) 5/4/95";
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 #include <unistd.h>
51 
52 #define	TAB	8
53 
54 void err __P((const char *, ...));
55 void check __P((FILE *));
56 void usage __P((void));
57 
58 int
59 main(argc, argv)
60 	int argc;
61 	char *argv[];
62 {
63 	register u_long column, start, stop;
64 	register 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 			err("illegal column -- %s", argv[1]);
82 		/* FALLTHROUGH */
83 	case 1:
84 		start = strtol(argv[0], &p, 10);
85 		if (start <= 0 || *p)
86 			err("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("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 void
124 check(stream)
125 	FILE *stream;
126 {
127 	if (feof(stream))
128 		exit(0);
129 	if (ferror(stream))
130 		err("%s: %s",
131 		    stream == stdin ? "stdin" : "stdout", strerror(errno));
132 }
133 
134 void
135 usage()
136 {
137 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
138 	exit(1);
139 }
140 
141 #if __STDC__
142 #include <stdarg.h>
143 #else
144 #include <varargs.h>
145 #endif
146 
147 void
148 #if __STDC__
149 err(const char *fmt, ...)
150 #else
151 err(fmt, va_alist)
152 	char *fmt;
153         va_dcl
154 #endif
155 {
156 	va_list ap;
157 #if __STDC__
158 	va_start(ap, fmt);
159 #else
160 	va_start(ap);
161 #endif
162 	(void)fprintf(stderr, "colrm: ");
163 	(void)vfprintf(stderr, fmt, ap);
164 	va_end(ap);
165 	(void)fprintf(stderr, "\n");
166 	exit(1);
167 	/* NOTREACHED */
168 }
169