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 \
35The 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
54struct tabspec {
55	const char *opt;
56	const char *spec;
57};
58static 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};
69static const size_t ntabspecs = sizeof(tabspecs) / sizeof(tabspecs[0]);
70
71__dead static void
72usage(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
82int
83main(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