xref: /freebsd/usr.bin/colrm/colrm.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1991, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif
35 
36 #if 0
37 #ifndef lint
38 static char sccsid[] = "@(#)colrm.c	8.2 (Berkeley) 5/4/95";
39 #endif
40 #endif
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/types.h>
46 #include <err.h>
47 #include <errno.h>
48 #include <limits.h>
49 #include <locale.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 #include <wchar.h>
55 
56 #define	TAB	8
57 
58 void check(FILE *);
59 static void usage(void);
60 
61 int
62 main(int argc, char *argv[])
63 {
64 	u_long column, start, stop;
65 	int ch, width;
66 	char *p;
67 
68 	setlocale(LC_ALL, "");
69 
70 	while ((ch = getopt(argc, argv, "")) != -1)
71 		switch(ch) {
72 		case '?':
73 		default:
74 			usage();
75 		}
76 	argc -= optind;
77 	argv += optind;
78 
79 	start = stop = 0;
80 	switch(argc) {
81 	case 2:
82 		stop = strtol(argv[1], &p, 10);
83 		if (stop <= 0 || *p)
84 			errx(1, "illegal column -- %s", argv[1]);
85 		/* FALLTHROUGH */
86 	case 1:
87 		start = strtol(argv[0], &p, 10);
88 		if (start <= 0 || *p)
89 			errx(1, "illegal column -- %s", argv[0]);
90 		break;
91 	case 0:
92 		break;
93 	default:
94 		usage();
95 	}
96 
97 	if (stop && start > stop)
98 		errx(1, "illegal start and stop columns");
99 
100 	for (column = 0;;) {
101 		switch (ch = getwchar()) {
102 		case WEOF:
103 			check(stdin);
104 			break;
105 		case '\b':
106 			if (column)
107 				--column;
108 			break;
109 		case '\n':
110 			column = 0;
111 			break;
112 		case '\t':
113 			column = (column + TAB) & ~(TAB - 1);
114 			break;
115 		default:
116 			if ((width = wcwidth(ch)) > 0)
117 				column += width;
118 			break;
119 		}
120 
121 		if ((!start || column < start || (stop && column > stop)) &&
122 		    putwchar(ch) == WEOF)
123 			check(stdout);
124 	}
125 }
126 
127 void
128 check(FILE *stream)
129 {
130 	if (feof(stream))
131 		exit(0);
132 	if (ferror(stream))
133 		err(1, "%s", stream == stdin ? "stdin" : "stdout");
134 }
135 
136 void
137 usage(void)
138 {
139 	(void)fprintf(stderr, "usage: colrm [start [stop]]\n");
140 	exit(1);
141 }
142 
143