xref: /netbsd/usr.bin/expand/expand.c (revision bf9ec67e)
1 /*	$NetBSD: expand.c,v 1.8 1999/02/10 16:15:31 kleink Exp $	*/
2 
3 /*
4  * Copyright (c) 1980, 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
45 #endif
46 __RCSID("$NetBSD: expand.c,v 1.8 1999/02/10 16:15:31 kleink Exp $");
47 #endif /* not lint */
48 
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <ctype.h>
52 #include <unistd.h>
53 
54 /*
55  * expand - expand tabs to equivalent spaces
56  */
57 int	nstops;
58 int	tabstops[100];
59 
60 static	void	getstops __P((char *));
61 	int	main __P((int, char **));
62 static	void	usage __P((void));
63 
64 int
65 main(argc, argv)
66 	int argc;
67 	char *argv[];
68 {
69 	int c, column;
70 	int n;
71 
72 	/* handle obsolete syntax */
73 	while (argc > 1 &&
74 	    argv[1][0] == '-' && isdigit((unsigned char)argv[1][1])) {
75 		getstops(&argv[1][1]);
76 		argc--; argv++;
77 	}
78 
79 	while ((c = getopt (argc, argv, "t:")) != -1) {
80 		switch (c) {
81 		case 't':
82 			getstops(optarg);
83 			break;
84 		case '?':
85 		default:
86 			usage();
87 			/* NOTREACHED */
88 		}
89 	}
90 	argc -= optind;
91 	argv += optind;
92 
93 	do {
94 		if (argc > 0) {
95 			if (freopen(argv[0], "r", stdin) == NULL) {
96 				perror(argv[0]);
97 				exit(EXIT_FAILURE);
98 			}
99 			argc--, argv++;
100 		}
101 		column = 0;
102 		while ((c = getchar()) != EOF) {
103 			switch (c) {
104 			case '\t':
105 				if (nstops == 0) {
106 					do {
107 						putchar(' ');
108 						column++;
109 					} while (column & 07);
110 					continue;
111 				}
112 				if (nstops == 1) {
113 					do {
114 						putchar(' ');
115 						column++;
116 					} while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
117 					continue;
118 				}
119 				for (n = 0; n < nstops; n++)
120 					if (tabstops[n] > column)
121 						break;
122 				if (n == nstops) {
123 					putchar(' ');
124 					column++;
125 					continue;
126 				}
127 				while (column < tabstops[n]) {
128 					putchar(' ');
129 					column++;
130 				}
131 				continue;
132 
133 			case '\b':
134 				if (column)
135 					column--;
136 				putchar('\b');
137 				continue;
138 
139 			default:
140 				putchar(c);
141 				column++;
142 				continue;
143 
144 			case '\n':
145 				putchar(c);
146 				column = 0;
147 				continue;
148 			}
149 		}
150 	} while (argc > 0);
151 	exit(EXIT_SUCCESS);
152 	/* NOTREACHED */
153 }
154 
155 static void
156 getstops(cp)
157 	char *cp;
158 {
159 	int i;
160 
161 	nstops = 0;
162 	for (;;) {
163 		i = 0;
164 		while (*cp >= '0' && *cp <= '9')
165 			i = i * 10 + *cp++ - '0';
166 		if (i <= 0 || i > 256) {
167 bad:
168 			fprintf(stderr, "Bad tab stop spec\n");
169 			exit(EXIT_FAILURE);
170 		}
171 		if (nstops > 0 && i <= tabstops[nstops-1])
172 			goto bad;
173 		tabstops[nstops++] = i;
174 		if (*cp == 0)
175 			break;
176 		if (*cp != ',' && *cp != ' ')
177 			goto bad;
178 		cp++;
179 	}
180 }
181 
182 static void
183 usage()
184 {
185 
186 	(void)fprintf(stderr, "usage: expand [-t tablist] [file ...]\n");
187 	exit(EXIT_FAILURE);
188 }
189