xref: /netbsd-src/usr.bin/tabs/tabs.c (revision fea9876874496f17a26dcb5535a87f5904c9201a)
1 /* $NetBSD: tabs.c,v 1.6 2021/08/27 18:28:41 rillig Exp $ */
2 
3 /*-
4  * Copyright (c) 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Roy Marples.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 2008 \
35 The NetBSD Foundation, inc. All rights reserved.");
36 __RCSID("$NetBSD: tabs.c,v 1.6 2021/08/27 18:28:41 rillig Exp $");
37 #endif /* not lint */
38 
39 #include <sys/ioctl.h>
40 #include <sys/types.h>
41 
42 #include <ctype.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <limits.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <term.h>
50 #include <unistd.h>
51 
52 #define NSTOPS 20
53 
54 struct tabspec {
55 	const char *opt;
56 	const char *spec;
57 };
58 static const struct tabspec tabspecs[] = {
59 	{"a",	"1,10,16,36,72"},
60 	{"a2",	"1,10,16,40,72"},
61 	{"c",	"1,8,12,16,20,55"},
62 	{"c2",	"1,6,10,14,49"},
63 	{"c3",	"1,6,10,14,18,22,26,30,34,38,42,46,50,54,58,62,67"},
64 	{"f",	"1,7,11,15,19,23"},
65 	{"p",	"1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61"},
66 	{"s",	"1,10,55"},
67 	{"u",	"1,12,20,44"}
68 };
69 static const size_t ntabspecs = sizeof(tabspecs) / sizeof(tabspecs[0]);
70 
71 __dead static void
usage(void)72 usage(void)
73 {
74 	fprintf(stderr,
75 		"usage: tabs [-n|-a|-a2|-c|-c2|-c3|-f|-p|-s|-u] [+m[n]]"
76 		" [-T type]\n"
77 		"       tabs [-T type] [+[n]] n1[,n2,...]\n");
78 	exit(EXIT_FAILURE);
79 	/* NOTREACHED */
80 }
81 
82 int
main(int argc,char ** argv)83 main(int argc, char **argv)
84 {
85 	char *term, *arg, *token, *end, *tabs = NULL, *p;
86 	const char *cr, *spec = NULL;
87 	int i, n, inc = 8, stops[NSTOPS], nstops, last, cols, margin = 0;
88 	long num = 0;
89 	size_t j;
90 	struct winsize ws;
91 
92 	term = getenv("TERM");
93 	for (i = 1; i < argc; i++) {
94 		if (argv[i][0] == '+') {
95 			arg = argv[i] + 1;
96 			if (arg[0] == 'm')
97 				arg++;
98 			if (arg[0] == '\0')
99 				margin = 10;
100 			else {
101 				errno = 0;
102 				num = strtol(arg, &end, 10);
103 				if (errno != 0 || *end != '\0' ||
104 				    num < 0 || num > INT_MAX)
105 					errx(EXIT_FAILURE,
106 					     "%s: invalid margin", arg);
107 				margin = (int)num;
108 			}
109 			continue;
110 		}
111 		if (argv[i][0] != '-') {
112 			tabs = argv[i];
113 			break;
114 		}
115 		arg = argv[i] + 1;
116 		if (arg[0] == '\0')
117 			usage();
118 		if (arg[0] == '-' && arg[1] == '\0') {
119 			if (argv[i + 1] != NULL)
120 				tabs = argv[i + 1];
121 			break;
122 		}
123 		if (arg[0] == 'T' && arg[1] == '\0') {
124 			term = argv[++i];
125 			if (term == NULL)
126 				usage();
127 			continue;
128 		}
129 		if (isdigit((unsigned char)arg[0])) {
130 			if (arg[1] != '\0')
131 				errx(EXIT_FAILURE,
132 				     "%s: invalid increment", arg);
133 			inc = arg[0] - '0';
134 			continue;
135 		}
136 		for (j = 0; j < ntabspecs; j++) {
137 			if (arg[0] == tabspecs[j].opt[0] &&
138 			    arg[1] == tabspecs[j].opt[1]) {
139 				spec = tabspecs[j].spec;
140 				break;
141 			}
142 		}
143 		if (j == ntabspecs)
144 			usage();
145 	}
146 	if (tabs == NULL && spec != NULL)
147 		tabs = strdup(spec);
148 
149 	if (tabs != NULL)
150 		last = nstops = 0;
151 	else
152 		nstops = -1;
153 	p = tabs;
154 	while ((token = strsep(&p, ", ")) != NULL) {
155 		if (*token == '\0')
156 			continue;
157 		if (nstops >= NSTOPS)
158 			errx(EXIT_FAILURE,
159 			     "too many tab stops (max %d)", NSTOPS);
160 		errno = 0;
161 		num = strtol(token, &end, 10);
162 		if (errno != 0 || *end != '\0' || num <= 0 || num > INT_MAX)
163 			errx(EXIT_FAILURE, "%s: invalid tab stop", token);
164 		n = (int)num;
165 		if (*token == '+') {
166 			if (nstops == 0)
167 				errx(EXIT_FAILURE,
168 				     "first tab stop may not be relative");
169 			n += last;
170 		}
171 		if (last > n)
172 			errx(EXIT_FAILURE, "tab stops may not go backwards");
173 		last = stops[nstops++] = n;
174 	}
175 
176 	if (term == NULL)
177 		errx(EXIT_FAILURE, "no value for $TERM and -T not given");
178 	if (setupterm(term, STDOUT_FILENO, NULL) != 0)
179 		err(EXIT_FAILURE, "setupterm:");
180 	cr = carriage_return;
181 	if (cr == NULL)
182 		cr = "\r";
183 	if (clear_all_tabs == NULL)
184 		errx(EXIT_FAILURE, "terminal cannot clear tabs");
185 	if (set_tab == NULL)
186 		errx(EXIT_FAILURE, "terminal cannot set tabs");
187 
188 	/* Clear existing tabs */
189 	putp(cr);
190 	putp(clear_all_tabs);
191 	putp(cr);
192 
193 	if (set_lr_margin != NULL) {
194 		printf("%*s", margin, "");
195 		putp(set_lr_margin);
196 	} else if (margin != 0)
197 		warnx("terminal cannot set left margin");
198 
199 	if (nstops >= 0) {
200 		printf("%*s", stops[0] - 1, "");
201 		putp(set_tab);
202 		for (i = 1; i < nstops; i++) {
203 			printf("%*s", stops[i] - stops[i - 1], "");
204 			putp(set_tab);
205 		}
206 	} else if (inc > 0) {
207 		cols = 0;
208 		term = getenv("COLUMNS");
209 		if (term != NULL) {
210 			errno = 0;
211 			num = strtol(term, &end, 10);
212 			if (errno == 0 && *end == '\0' &&
213 			    0 <= cols && cols <= INT_MAX)
214 				cols = (int)num;
215 		}
216 		if (cols == 0) {
217 			if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0)
218 				cols = ws.ws_col;
219 			else {
220 				cols = tigetnum("cols");
221 				if (cols == 0) {
222 					cols = 80;
223 					warnx("terminal does not specify number"
224 					      "columns; defaulting to %d",
225 					      cols);
226 				}
227 			}
228 		}
229 		for (i = 0; i < cols / inc; i++) {
230 			printf("%*s", inc, "");
231 			putp(set_tab);
232 		}
233 	}
234 	putp(cr);
235 
236 	exit(EXIT_SUCCESS);
237 	/* NOTREACHED */
238 }
239