xref: /netbsd-src/usr.bin/expand/expand.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*
2  * Copyright (c) 1980 The Regents of the University of California.
3  * 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 char copyright[] =
36 "@(#) Copyright (c) 1980 The Regents of the University of California.\n\
37  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 /*static char sccsid[] = "from: @(#)expand.c	5.3 (Berkeley) 6/1/90";*/
42 static char rcsid[] = "$Id: expand.c,v 1.4 1993/10/13 18:34:09 jtc Exp $";
43 #endif /* not lint */
44 
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <ctype.h>
48 #include <unistd.h>
49 
50 /*
51  * expand - expand tabs to equivalent spaces
52  */
53 int	nstops;
54 int	tabstops[100];
55 
56 static void getstops();
57 static void usage();
58 
59 int
60 main(argc, argv)
61 	int argc;
62 	char *argv[];
63 {
64 	register int c, column;
65 	register int n;
66 
67 	/* handle obsolete syntax */
68 	while (argc > 1 && argv[1][0] && isdigit(argv[1][1])) {
69 		getstops(&argv[1][1]);
70 		argc--; argv++;
71 	}
72 
73 	while ((c = getopt (argc, argv, "t:")) != -1) {
74 		switch (c) {
75 		case 't':
76 			getstops(optarg);
77 			break;
78 		case '?':
79 		default:
80 			usage();
81 			/* NOTREACHED */
82 		}
83 	}
84 	argc -= optind;
85 	argv += optind;
86 
87 	do {
88 		if (argc > 0) {
89 			if (freopen(argv[0], "r", stdin) == NULL) {
90 				perror(argv[0]);
91 				exit(1);
92 			}
93 			argc--, argv++;
94 		}
95 		column = 0;
96 		while ((c = getchar()) != EOF) {
97 			switch (c) {
98 			case '\t':
99 				if (nstops == 0) {
100 					do {
101 						putchar(' ');
102 						column++;
103 					} while (column & 07);
104 					continue;
105 				}
106 				if (nstops == 1) {
107 					do {
108 						putchar(' ');
109 						column++;
110 					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
111 					continue;
112 				}
113 				for (n = 0; n < nstops; n++)
114 					if (tabstops[n] > column)
115 						break;
116 				if (n == nstops) {
117 					putchar(' ');
118 					column++;
119 					continue;
120 				}
121 				while (column < tabstops[n]) {
122 					putchar(' ');
123 					column++;
124 				}
125 				continue;
126 
127 			case '\b':
128 				if (column)
129 					column--;
130 				putchar('\b');
131 				continue;
132 
133 			default:
134 				putchar(c);
135 				column++;
136 				continue;
137 
138 			case '\n':
139 				putchar(c);
140 				column = 0;
141 				continue;
142 			}
143 		}
144 	} while (argc > 0);
145 	exit(0);
146 }
147 
148 static void
149 getstops(cp)
150 	register char *cp;
151 {
152 	register int i;
153 
154 	nstops = 0;
155 	for (;;) {
156 		i = 0;
157 		while (*cp >= '0' && *cp <= '9')
158 			i = i * 10 + *cp++ - '0';
159 		if (i <= 0 || i > 256) {
160 bad:
161 			fprintf(stderr, "Bad tab stop spec\n");
162 			exit(1);
163 		}
164 		if (nstops > 0 && i <= tabstops[nstops-1])
165 			goto bad;
166 		tabstops[nstops++] = i;
167 		if (*cp == 0)
168 			break;
169 		if (*cp != ',' && *cp != ' ')
170 			goto bad;
171 		cp++;
172 	}
173 }
174 
175 static void
176 usage()
177 {
178 	(void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
179 	exit(1);
180 }
181