xref: /openbsd-src/usr.bin/expand/expand.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: expand.c,v 1.3 1998/01/22 17:41:09 deraadt Exp $	*/
2 /*	$NetBSD: expand.c,v 1.5 1995/09/02 06:19:46 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static char copyright[] =
39 "@(#) Copyright (c) 1980, 1993\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
46 #endif
47 static char rcsid[] = "$OpenBSD: expand.c,v 1.3 1998/01/22 17:41:09 deraadt Exp $";
48 #endif /* not lint */
49 
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <ctype.h>
53 #include <unistd.h>
54 
55 /*
56  * expand - expand tabs to equivalent spaces
57  */
58 int	nstops;
59 int	tabstops[100];
60 
61 static void getstops();
62 static void usage();
63 
64 int
65 main(argc, argv)
66 	int argc;
67 	char *argv[];
68 {
69 	register int c, column;
70 	register int n;
71 
72 	/* handle obsolete syntax */
73 	while (argc > 1 && argv[1][0] == '-' && isdigit(argv[1][1])) {
74 		getstops(&argv[1][1]);
75 		argc--; argv++;
76 	}
77 
78 	while ((c = getopt (argc, argv, "t:")) != -1) {
79 		switch (c) {
80 		case 't':
81 			getstops(optarg);
82 			break;
83 		case '?':
84 		default:
85 			usage();
86 			/* NOTREACHED */
87 		}
88 	}
89 	argc -= optind;
90 	argv += optind;
91 
92 	do {
93 		if (argc > 0) {
94 			if (freopen(argv[0], "r", stdin) == NULL) {
95 				perror(argv[0]);
96 				exit(1);
97 			}
98 			argc--, argv++;
99 		}
100 		column = 0;
101 		while ((c = getchar()) != EOF) {
102 			switch (c) {
103 			case '\t':
104 				if (nstops == 0) {
105 					do {
106 						putchar(' ');
107 						column++;
108 					} while (column & 07);
109 					continue;
110 				}
111 				if (nstops == 1) {
112 					do {
113 						putchar(' ');
114 						column++;
115 					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
116 					continue;
117 				}
118 				for (n = 0; n < nstops; n++)
119 					if (tabstops[n] > column)
120 						break;
121 				if (n == nstops) {
122 					putchar(' ');
123 					column++;
124 					continue;
125 				}
126 				while (column < tabstops[n]) {
127 					putchar(' ');
128 					column++;
129 				}
130 				continue;
131 
132 			case '\b':
133 				if (column)
134 					column--;
135 				putchar('\b');
136 				continue;
137 
138 			default:
139 				putchar(c);
140 				column++;
141 				continue;
142 
143 			case '\n':
144 				putchar(c);
145 				column = 0;
146 				continue;
147 			}
148 		}
149 	} while (argc > 0);
150 	exit(0);
151 }
152 
153 static void
154 getstops(cp)
155 	register char *cp;
156 {
157 	register int i;
158 
159 	nstops = 0;
160 	for (;;) {
161 		i = 0;
162 		while (*cp >= '0' && *cp <= '9')
163 			i = i * 10 + *cp++ - '0';
164 		if (i <= 0 || i > 256) {
165 bad:
166 			fprintf(stderr, "Bad tab stop spec\n");
167 			exit(1);
168 		}
169 		if (nstops > 0 && i <= tabstops[nstops-1])
170 			goto bad;
171 		tabstops[nstops++] = i;
172 		if (*cp == 0)
173 			break;
174 		if (*cp != ',' && *cp != ' ')
175 			goto bad;
176 		cp++;
177 	}
178 }
179 
180 static void
181 usage()
182 {
183 	(void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
184 	exit(1);
185 }
186