xref: /freebsd/usr.bin/colrm/colrm.c (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
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 #endif
40 
41 #include <sys/cdefs.h>
42 #include <sys/types.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <limits.h>
46 #include <locale.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <wchar.h>
52 
53 #define	TAB	8
54 
55 void check(FILE *);
56 static void usage(void) __dead2;
57 
58 int
59 main(int argc, char *argv[])
60 {
61 	u_long column, start, stop;
62 	int ch, width;
63 	char *p;
64 
65 	setlocale(LC_ALL, "");
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 			errx(1, "illegal column -- %s", argv[1]);
82 		/* FALLTHROUGH */
83 	case 1:
84 		start = strtol(argv[0], &p, 10);
85 		if (start <= 0 || *p)
86 			errx(1, "illegal column -- %s", argv[0]);
87 		break;
88 	case 0:
89 		break;
90 	default:
91 		usage();
92 	}
93 
94 	if (stop && start > stop)
95 		errx(1, "illegal start and stop columns");
96 
97 	for (column = 0;;) {
98 		switch (ch = getwchar()) {
99 		case WEOF:
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 			if ((width = wcwidth(ch)) > 0)
114 				column += width;
115 			break;
116 		}
117 
118 		if ((!start || column < start || (stop && column > stop)) &&
119 		    putwchar(ch) == WEOF)
120 			check(stdout);
121 	}
122 }
123 
124 void
125 check(FILE *stream)
126 {
127 	if (feof(stream))
128 		exit(0);
129 	if (ferror(stream))
130 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
131 }
132 
133 void
134 usage(void)
135 {
136 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
137 	exit(1);
138 }
139 
140