xref: /freebsd/usr.bin/colrm/colrm.c (revision db33c6f3ae9d1231087710068ee4ea5398aacca7)
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 #include <sys/types.h>
33 #include <err.h>
34 #include <errno.h>
35 #include <limits.h>
36 #include <locale.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41 #include <wchar.h>
42 
43 #include <capsicum_helpers.h>
44 
45 #define	TAB	8
46 
47 void check(FILE *);
48 static void usage(void) __dead2;
49 
50 int
51 main(int argc, char *argv[])
52 {
53 	u_long column, start, stop;
54 	int ch, width;
55 	char *p;
56 
57 	setlocale(LC_ALL, "");
58 
59 	caph_cache_catpages();
60 	if (caph_limit_stdio() < 0 || caph_enter() < 0)
61 		err(EXIT_FAILURE, "capsicum");
62 
63 	while ((ch = getopt(argc, argv, "")) != -1)
64 		switch(ch) {
65 		case '?':
66 		default:
67 			usage();
68 		}
69 	argc -= optind;
70 	argv += optind;
71 
72 	start = stop = 0;
73 	switch(argc) {
74 	case 2:
75 		stop = strtol(argv[1], &p, 10);
76 		if (stop <= 0 || *p)
77 			errx(EXIT_FAILURE, "illegal column -- %s", argv[1]);
78 		/* FALLTHROUGH */
79 	case 1:
80 		start = strtol(argv[0], &p, 10);
81 		if (start <= 0 || *p)
82 			errx(EXIT_FAILURE, "illegal column -- %s", argv[0]);
83 		break;
84 	case 0:
85 		break;
86 	default:
87 		usage();
88 	}
89 
90 	if (stop && start > stop)
91 		errx(EXIT_FAILURE, "illegal start and stop columns");
92 
93 	for (column = 0;;) {
94 		switch (ch = getwchar()) {
95 		case WEOF:
96 			check(stdin);
97 			break;
98 		case '\b':
99 			if (column)
100 				--column;
101 			break;
102 		case '\n':
103 			column = 0;
104 			break;
105 		case '\t':
106 			column = (column + TAB) & ~(TAB - 1);
107 			break;
108 		default:
109 			if ((width = wcwidth(ch)) > 0)
110 				column += width;
111 			break;
112 		}
113 
114 		if ((!start || column < start || (stop && column > stop)) &&
115 		    putwchar(ch) == WEOF)
116 			check(stdout);
117 	}
118 }
119 
120 void
121 check(FILE *stream)
122 {
123 	if (feof(stream))
124 		exit(EXIT_SUCCESS);
125 	if (ferror(stream))
126 		err(EXIT_FAILURE, "%s", stream == stdin ? "stdin" : "stdout");
127 }
128 
129 void
130 usage(void)
131 {
132 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
133 	exit(EXIT_FAILURE);
134 }
135