xref: /freebsd/usr.bin/unexpand/unexpand.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
1 /*-
2  * Copyright (c) 1980, 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 #include <sys/cdefs.h>
35 
36 __FBSDID("$FreeBSD$");
37 
38 #ifndef lint
39 static const char copyright[] =
40 "@(#) Copyright (c) 1980, 1993\n\
41 	The Regents of the University of California.  All rights reserved.\n";
42 #endif
43 
44 #ifndef lint
45 static const char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
46 #endif
47 
48 /*
49  * unexpand - put tabs into a file replacing blanks
50  */
51 #include <ctype.h>
52 #include <err.h>
53 #include <limits.h>
54 #include <locale.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 
60 int	all;
61 int	nstops;
62 int	tabstops[100];
63 
64 static void getstops(const char *);
65 static void usage(void);
66 static void tabify(void);
67 
68 int
69 main(int argc, char *argv[])
70 {
71 	int ch, failed;
72 	char *filename;
73 
74 	setlocale(LC_CTYPE, "");
75 
76 	nstops = 1;
77 	tabstops[0] = 8;
78 	while ((ch = getopt(argc, argv, "at:")) != -1) {
79 		switch (ch) {
80 		case 'a':	/* Un-expand all spaces, not just leading. */
81 			all = 1;
82 			break;
83 		case 't':	/* Specify tab list, implies -a. */
84 			getstops(optarg);
85 			all = 1;
86 			break;
87 		default:
88 			usage();
89 			/*NOTREACHED*/
90 		}
91 	}
92 	argc -= optind;
93 	argv += optind;
94 
95 	failed = 0;
96 	if (argc == 0)
97 		tabify();
98 	else {
99 		while ((filename = *argv++) != NULL) {
100 			if (freopen(filename, "r", stdin) == NULL) {
101 				warn("%s", filename);
102 				failed++;
103 			} else
104 				tabify();
105 		}
106 	}
107 	exit(failed != 0);
108 }
109 
110 static void
111 usage(void)
112 {
113 	fprintf(stderr, "usage: unexpand [-a] [-t tablist] [file ...]\n");
114 	exit(1);
115 }
116 
117 static void
118 tabify(void)
119 {
120 	int ch, dcol, doneline, limit, n, ocol;
121 
122 	limit = nstops == 1 ? INT_MAX : tabstops[nstops - 1] - 1;
123 
124 	doneline = ocol = dcol = 0;
125 	while ((ch = getchar()) != EOF) {
126 		if (ch == ' ' && !doneline) {
127 			if (++dcol >= limit)
128 				doneline = 1;
129 			continue;
130 		} else if (ch == '\t') {
131 			if (nstops == 1) {
132 				dcol = (1 + dcol / tabstops[0]) *
133 				    tabstops[0];
134 				continue;
135 			} else {
136 				for (n = 0; tabstops[n] - 1 < dcol &&
137 				    n < nstops; n++)
138 					;
139 				if (n < nstops - 1 && tabstops[n] - 1 < limit) {
140 					dcol = tabstops[n];
141 					continue;
142 				}
143 				doneline = 1;
144 			}
145 		}
146 
147 		/* Output maximal number of tabs. */
148 		if (nstops == 1) {
149 			while (((ocol + tabstops[0]) / tabstops[0])
150 			    <= (dcol / tabstops[0])) {
151 				if (dcol - ocol < 2)
152 					break;
153 				putchar('\t');
154 				ocol = (1 + ocol / tabstops[0]) *
155 				    tabstops[0];
156 			}
157 		} else {
158 			for (n = 0; tabstops[n] - 1 < ocol && n < nstops; n++)
159 				;
160 			while (ocol < dcol && n < nstops && ocol < limit) {
161 				putchar('\t');
162 				ocol = tabstops[n++];
163 			}
164 		}
165 
166 		/* Then spaces. */
167 		while (ocol < dcol && ocol < limit) {
168 			putchar(' ');
169 			ocol++;
170 		}
171 
172 		if (ch == '\b') {
173 			putchar('\b');
174 			if (ocol > 0)
175 				ocol--, dcol--;
176 		} else if (ch == '\n') {
177 			putchar('\n');
178 			doneline = ocol = dcol = 0;
179 			continue;
180 		} else if (ch != ' ' || dcol > limit) {
181 			putchar(ch);
182 			if (isprint(ch))
183 				ocol++, dcol++;
184 		}
185 
186 		/*
187 		 * Only processing leading blanks or we've gone past the
188 		 * last tab stop. Emit remainder of this line unchanged.
189 		 */
190 		if (!all || dcol >= limit) {
191 			while ((ch = getchar()) != '\n' && ch != EOF)
192 				putchar(ch);
193 			if (ch == '\n')
194 				putchar('\n');
195 			doneline = ocol = dcol = 0;
196 		}
197 	}
198 }
199 
200 static void
201 getstops(const char *cp)
202 {
203 	int i;
204 
205 	nstops = 0;
206 	for (;;) {
207 		i = 0;
208 		while (*cp >= '0' && *cp <= '9')
209 			i = i * 10 + *cp++ - '0';
210 		if (i <= 0)
211 			errx(1, "bad tab stop spec");
212 		if (nstops > 0 && i <= tabstops[nstops-1])
213 			errx(1, "bad tab stop spec");
214 		if (nstops == sizeof(tabstops) / sizeof(*tabstops))
215 			errx(1, "too many tab stops");
216 		tabstops[nstops++] = i;
217 		if (*cp == 0)
218 			break;
219 		if (*cp != ',' && !isblank((unsigned char)*cp))
220 			errx(1, "bad tab stop spec");
221 		cp++;
222 	}
223 }
224