1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2002 Tim J. Robbins.
5 * 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 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29/*
30 * tabs -- set terminal tabs
31 *
32 * This utility displays a series of characters that clears the terminal
33 * hardware tab settings, then initialises them to specified values,
34 * and optionally sets a soft margin.
35 */
36
37#include <sys/types.h>
38#include <sys/tty.h>
39
40#include <ctype.h>
41#include <err.h>
42#include <errno.h>
43#include <locale.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <term.h>
48#include <unistd.h>
49
50/* Maximum number of tab stops allowed in table. */
51#define NSTOPS		20
52
53#define NELEMS(a) (sizeof(a) / sizeof(a[0]))
54
55/* Predefined formats, taken from IEEE Std 1003.1-2001. */
56static const struct {
57	const char	*name;		/* Format name used on cmd. line */
58	long		stops[NSTOPS];	/* Column positions */
59} formats[] = {
60	{ "a",	{ 1, 10, 16, 36, 72 } },
61	{ "a2",	{ 1, 10, 16, 40, 72 } },
62	{ "c",	{ 1, 8, 12, 16, 20, 55 } },
63	{ "c2",	{ 1, 6, 10, 14, 49 } },
64	{ "c3", { 1, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 58,
65		62, 67 } },
66	{ "f",	{ 1, 7, 11, 15, 19, 23 } },
67	{ "p",	{ 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57,
68		61 } },
69	{ "s",	{ 1, 10, 55 } },
70	{ "u",	{ 1, 12, 20, 44 } }
71};
72
73static void	 gettabs(char *, long *, long *);
74static int	 ttywidth(void);
75static void	 usage(void);
76
77int
78main(int argc __unused, char *argv[])
79{
80	long cols, i, inc, j, margin, nstops, stops[NSTOPS];
81	const char *cr, *ct, *st, *ML;
82	char area[1024], *ap, *arg, *end;
83
84	setlocale(LC_ALL, "");
85
86	inc = 8;
87	margin = 0;
88	nstops = -1;
89	while ((arg = *++argv) != NULL && (*arg == '-' || *arg == '+')) {
90		if (*arg == '+') {
91			/* +m[n] or +[n] */
92			if (*++arg == 'm')
93				arg++;
94			if (*arg != '\0') {
95				errno = 0;
96				margin = strtol(arg, &end, 10);
97				if (errno != 0 || *end != '\0' || margin < 0)
98					errx(1, "%s: invalid margin width",
99					    arg);
100			} else
101				margin = 10;
102		} else if (isdigit(arg[1])) {
103			/* -n */
104			errno = 0;
105			inc = strtol(arg + 1, &end, 10);
106			if (errno != 0 || *end != '\0' || inc < 0)
107				errx(1, "%s: invalid increment", arg + 1);
108		} else if (arg[1] == 'T') {
109			/* -Ttype or -T type */
110			if (arg[2] != '\0')
111				setenv("TERM", arg + 2, 1);
112			else {
113				if ((arg = *++argv) == NULL)
114					usage();
115				setenv("TERM", arg, 1);
116			}
117		} else if (arg[1] == '-') {
118			arg = *++argv;
119			break;
120		} else {
121			/* Predefined format */
122			for (i = 0; i < (int)NELEMS(formats); i++)
123				if (strcmp(formats[i].name, arg + 1) == 0)
124					break;
125			if (i == NELEMS(formats))
126				usage();
127			for (j = nstops = 0; j < NSTOPS &&
128			    formats[i].stops[j] != 0; j++)
129				stops[nstops++] = formats[i].stops[j];
130		}
131	}
132
133	if (arg != NULL) {
134		if (nstops != -1)
135			usage();
136		gettabs(arg, stops, &nstops);
137	}
138
139	/* Initialise terminal, get the strings we need */
140	setupterm(NULL, 1, NULL);
141	ap = area;
142	if ((ct = tgetstr("ct", &ap)) == NULL)
143		errx(1, "terminal cannot clear tabs");
144	if ((st = tgetstr("st", &ap)) == NULL)
145		errx(1, "terminal cannot set tabs");
146	if ((cr = tgetstr("cr", &ap)) == NULL)
147		cr = "\r";
148	ML = tgetstr("ML", &ap);
149	cols = ttywidth();
150
151	/* Clear all tabs. */
152	putp(cr);
153	putp(ct);
154
155	/*
156	 * Set soft margin.
157	 * XXX Does this actually work?
158	 */
159	if (ML != NULL) {
160		printf("%*s", (int)margin, "");
161		putp(ML);
162	} else if (margin != 0)
163		warnx("terminal cannot set left margin");
164
165	/* Optionally output new tab stops. */
166	if (nstops >= 0) {
167		printf("%*s", (int)stops[0] - 1, "");
168		putp(st);
169		for (i = 1; i < nstops; i++) {
170			printf("%*s", (int)(stops[i] - stops[i - 1]), "");
171			putp(st);
172		}
173	} else if (inc > 0) {
174		for (i = 0; i < cols / inc; i++) {
175			putp(st);
176			printf("%*s", (int)inc, "");
177		}
178		putp(st);
179	}
180	putp(cr);
181
182	exit(0);
183}
184
185static void
186usage(void)
187{
188
189	fprintf(stderr,
190"usage: tabs [-n|-a|-a2|-c|-c2|-c3|-f|-p|-s|-u] [+m[n]] [-T type]\n");
191	fprintf(stderr,
192"       tabs [-T type] [+[n]] n1,[n2,...]\n");
193	exit(1);
194}
195
196static void
197gettabs(char *arg, long stops[], long *nstops)
198{
199	char *tok, *end;
200	long last, stop;
201
202	for (last = *nstops = 0, tok = strtok(arg, ","); tok != NULL;
203	    tok = strtok(NULL, ",")) {
204		if (*nstops >= NSTOPS)
205			errx(1, "too many tab stops (limit %d)", NSTOPS);
206		errno = 0;
207		stop = strtol(tok, &end, 10);
208		if (errno != 0 || *end != '\0' || stop <= 0)
209			errx(1, "%s: invalid tab stop", tok);
210		if (*tok == '+') {
211			if (tok == arg)
212				errx(1, "%s: first tab may not be relative",
213				    tok);
214			stop += last;
215		}
216		if (last > stop)
217			errx(1, "cannot go backwards");
218		last = stops[(*nstops)++] = stop;
219	}
220}
221
222static int
223ttywidth(void)
224{
225	struct winsize ws;
226	int width;
227
228	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1)
229		width = ws.ws_col;
230	else if ((width = tgetnum("co")) == 0) {
231		width = 80;
232		warnx("cannot find terminal width; defaulted to %d", width);
233	}
234
235	return (width);
236}
237