xref: /freebsd/usr.bin/colrm/colrm.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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 #define	TAB	8
44 
45 void check(FILE *);
46 static void usage(void) __dead2;
47 
48 int
49 main(int argc, char *argv[])
50 {
51 	u_long column, start, stop;
52 	int ch, width;
53 	char *p;
54 
55 	setlocale(LC_ALL, "");
56 
57 	while ((ch = getopt(argc, argv, "")) != -1)
58 		switch(ch) {
59 		case '?':
60 		default:
61 			usage();
62 		}
63 	argc -= optind;
64 	argv += optind;
65 
66 	start = stop = 0;
67 	switch(argc) {
68 	case 2:
69 		stop = strtol(argv[1], &p, 10);
70 		if (stop <= 0 || *p)
71 			errx(1, "illegal column -- %s", argv[1]);
72 		/* FALLTHROUGH */
73 	case 1:
74 		start = strtol(argv[0], &p, 10);
75 		if (start <= 0 || *p)
76 			errx(1, "illegal column -- %s", argv[0]);
77 		break;
78 	case 0:
79 		break;
80 	default:
81 		usage();
82 	}
83 
84 	if (stop && start > stop)
85 		errx(1, "illegal start and stop columns");
86 
87 	for (column = 0;;) {
88 		switch (ch = getwchar()) {
89 		case WEOF:
90 			check(stdin);
91 			break;
92 		case '\b':
93 			if (column)
94 				--column;
95 			break;
96 		case '\n':
97 			column = 0;
98 			break;
99 		case '\t':
100 			column = (column + TAB) & ~(TAB - 1);
101 			break;
102 		default:
103 			if ((width = wcwidth(ch)) > 0)
104 				column += width;
105 			break;
106 		}
107 
108 		if ((!start || column < start || (stop && column > stop)) &&
109 		    putwchar(ch) == WEOF)
110 			check(stdout);
111 	}
112 }
113 
114 void
115 check(FILE *stream)
116 {
117 	if (feof(stream))
118 		exit(0);
119 	if (ferror(stream))
120 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
121 }
122 
123 void
124 usage(void)
125 {
126 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
127 	exit(1);
128 }
129 
130