xref: /freebsd/usr.bin/colrm/colrm.c (revision 0a36787e4c1fa0cf77dcf83be0867178476e372b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1991, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif
37 
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)colrm.c	8.2 (Berkeley) 5/4/95";
41 #endif
42 #endif
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <sys/types.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <limits.h>
51 #include <locale.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include <wchar.h>
57 
58 #define	TAB	8
59 
60 void check(FILE *);
61 static void usage(void);
62 
63 int
64 main(int argc, char *argv[])
65 {
66 	u_long column, start, stop;
67 	int ch, width;
68 	char *p;
69 
70 	setlocale(LC_ALL, "");
71 
72 	while ((ch = getopt(argc, argv, "")) != -1)
73 		switch(ch) {
74 		case '?':
75 		default:
76 			usage();
77 		}
78 	argc -= optind;
79 	argv += optind;
80 
81 	start = stop = 0;
82 	switch(argc) {
83 	case 2:
84 		stop = strtol(argv[1], &p, 10);
85 		if (stop <= 0 || *p)
86 			errx(1, "illegal column -- %s", argv[1]);
87 		/* FALLTHROUGH */
88 	case 1:
89 		start = strtol(argv[0], &p, 10);
90 		if (start <= 0 || *p)
91 			errx(1, "illegal column -- %s", argv[0]);
92 		break;
93 	case 0:
94 		break;
95 	default:
96 		usage();
97 	}
98 
99 	if (stop && start > stop)
100 		errx(1, "illegal start and stop columns");
101 
102 	for (column = 0;;) {
103 		switch (ch = getwchar()) {
104 		case WEOF:
105 			check(stdin);
106 			break;
107 		case '\b':
108 			if (column)
109 				--column;
110 			break;
111 		case '\n':
112 			column = 0;
113 			break;
114 		case '\t':
115 			column = (column + TAB) & ~(TAB - 1);
116 			break;
117 		default:
118 			if ((width = wcwidth(ch)) > 0)
119 				column += width;
120 			break;
121 		}
122 
123 		if ((!start || column < start || (stop && column > stop)) &&
124 		    putwchar(ch) == WEOF)
125 			check(stdout);
126 	}
127 }
128 
129 void
130 check(FILE *stream)
131 {
132 	if (feof(stream))
133 		exit(0);
134 	if (ferror(stream))
135 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
136 }
137 
138 void
139 usage(void)
140 {
141 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
142 	exit(1);
143 }
144 
145