xref: /freebsd/usr.bin/colrm/colrm.c (revision 7bd6fde3951af84ef3b68e4d1eadc1840c2fc1b3)
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 const char copyright[] =
36 "@(#) Copyright (c) 1991, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif
39 
40 #if 0
41 #ifndef lint
42 static char sccsid[] = "@(#)colrm.c	8.2 (Berkeley) 5/4/95";
43 #endif
44 #endif
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include <sys/types.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <limits.h>
53 #include <locale.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 #include <wchar.h>
59 
60 #define	TAB	8
61 
62 void check(FILE *);
63 static void usage(void);
64 
65 int
66 main(int argc, char *argv[])
67 {
68 	u_long column, start, stop;
69 	int ch, width;
70 	char *p;
71 
72 	setlocale(LC_ALL, "");
73 
74 	while ((ch = getopt(argc, argv, "")) != -1)
75 		switch(ch) {
76 		case '?':
77 		default:
78 			usage();
79 		}
80 	argc -= optind;
81 	argv += optind;
82 
83 	start = stop = 0;
84 	switch(argc) {
85 	case 2:
86 		stop = strtol(argv[1], &p, 10);
87 		if (stop <= 0 || *p)
88 			errx(1, "illegal column -- %s", argv[1]);
89 		/* FALLTHROUGH */
90 	case 1:
91 		start = strtol(argv[0], &p, 10);
92 		if (start <= 0 || *p)
93 			errx(1, "illegal column -- %s", argv[0]);
94 		break;
95 	case 0:
96 		break;
97 	default:
98 		usage();
99 	}
100 
101 	if (stop && start > stop)
102 		errx(1, "illegal start and stop columns");
103 
104 	for (column = 0;;) {
105 		switch (ch = getwchar()) {
106 		case WEOF:
107 			check(stdin);
108 			break;
109 		case '\b':
110 			if (column)
111 				--column;
112 			break;
113 		case '\n':
114 			column = 0;
115 			break;
116 		case '\t':
117 			column = (column + TAB) & ~(TAB - 1);
118 			break;
119 		default:
120 			if ((width = wcwidth(ch)) > 0)
121 				column += width;
122 			break;
123 		}
124 
125 		if ((!start || column < start || (stop && column > stop)) &&
126 		    putwchar(ch) == WEOF)
127 			check(stdout);
128 	}
129 }
130 
131 void
132 check(FILE *stream)
133 {
134 	if (feof(stream))
135 		exit(0);
136 	if (ferror(stream))
137 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
138 }
139 
140 void
141 usage(void)
142 {
143 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
144 	exit(1);
145 }
146 
147