1/*-
2 * Copyright (c) 2002 Tim J. Robbins.
3 * 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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * tabs -- set terminal tabs
29 *
30 * This utility displays a series of characters that clears the terminal
31 * hardware tab settings, then initialises them to specified values,
32 * and optionally sets a soft margin.
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD$");
37
38#include <sys/types.h>
39#include <sys/tty.h>
40
41#include <ctype.h>
42#include <err.h>
43#include <errno.h>
44#include <locale.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48#include <term.h>
49#include <unistd.h>
50
51/* Maximum number of tab stops allowed in table. */
52#define NSTOPS		20
53
54#define NELEMS(a) (sizeof(a) / sizeof(a[0]))
55
56/* Predefined formats, taken from IEEE Std 1003.1-2001. */
57static const struct {
58	const char	*name;		/* Format name used on cmd. line */
59	long		stops[NSTOPS];	/* Column positions */
60} formats[] = {
61	{ "a",	{ 1, 10, 16, 36, 72 } },
62	{ "a2",	{ 1, 10, 16, 40, 72 } },
63	{ "c",	{ 1, 8, 12, 16, 20, 55 } },
64	{ "c2",	{ 1, 6, 10, 14, 49 } },
65	{ "c3", { 1, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 58,
66		62, 67 } },
67	{ "f",	{ 1, 7, 11, 15, 19, 23 } },
68	{ "p",	{ 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57,
69		61 } },
70	{ "s",	{ 1, 10, 55 } },
71	{ "u",	{ 1, 12, 20, 44 } }
72};
73
74static void	 gettabs(char *, long *, long *);
75static int	 ttywidth(void);
76static void	 usage(void);
77
78int
79main(int argc __unused, char *argv[])
80{
81	long cols, i, inc, j, margin, nstops, stops[NSTOPS];
82	const char *cr, *ct, *st, *ML;
83	char area[1024], *ap, *arg, *end;
84
85	setlocale(LC_ALL, "");
86
87	inc = 8;
88	margin = 0;
89	nstops = -1;
90	while ((arg = *++argv) != NULL && (*arg == '-' || *arg == '+')) {
91		if (*arg == '+') {
92			/* +m[n] or +[n] */
93			if (*++arg == 'm')
94				arg++;
95			if (*arg != '\0') {
96				errno = 0;
97				margin = strtol(arg, &end, 10);
98				if (errno != 0 || *end != '\0' || margin < 0)
99					errx(1, "%s: invalid margin width",
100					    arg);
101			} else
102				margin = 10;
103		} else if (isdigit(arg[1])) {
104			/* -n */
105			errno = 0;
106			inc = strtol(arg + 1, &end, 10);
107			if (errno != 0 || *end != '\0' || inc < 0)
108				errx(1, "%s: invalid increment", arg + 1);
109		} else if (arg[1] == 'T') {
110			/* -Ttype or -T type */
111			if (arg[2] != '\0')
112				setenv("TERM", arg + 2, 1);
113			else {
114				if ((arg = *++argv) == NULL)
115					usage();
116				setenv("TERM", arg, 1);
117			}
118		} else if (arg[1] == '-') {
119			arg = *++argv;
120			break;
121		} else {
122			/* Predefined format */
123			for (i = 0; i < (int)NELEMS(formats); i++)
124				if (strcmp(formats[i].name, arg + 1) == 0)
125					break;
126			if (i == NELEMS(formats))
127				usage();
128			for (j = nstops = 0; j < NSTOPS &&
129			    formats[i].stops[j] != 0; j++)
130				stops[nstops++] = formats[i].stops[j];
131		}
132	}
133
134	if (arg != NULL) {
135		if (nstops != -1)
136			usage();
137		gettabs(arg, stops, &nstops);
138	}
139
140	/* Initialise terminal, get the strings we need */
141	setupterm(NULL, 1, NULL);
142	ap = area;
143	if ((ct = tgetstr("ct", &ap)) == NULL)
144		errx(1, "terminal cannot clear tabs");
145	if ((st = tgetstr("st", &ap)) == NULL)
146		errx(1, "terminal cannot set tabs");
147	if ((cr = tgetstr("cr", &ap)) == NULL)
148		cr = "\r";
149	ML = tgetstr("ML", &ap);
150	cols = ttywidth();
151
152	/* Clear all tabs. */
153	putp(cr);
154	putp(ct);
155
156	/*
157	 * Set soft margin.
158	 * XXX Does this actually work?
159	 */
160	if (ML != NULL) {
161		printf("%*s", (int)margin, "");
162		putp(ML);
163	} else if (margin != 0)
164		warnx("terminal cannot set left margin");
165
166	/* Optionally output new tab stops. */
167	if (nstops >= 0) {
168		printf("%*s", (int)stops[0] - 1, "");
169		putp(st);
170		for (i = 1; i < nstops; i++) {
171			printf("%*s", (int)(stops[i] - stops[i - 1]), "");
172			putp(st);
173		}
174	} else if (inc > 0) {
175		for (i = 0; i < cols / inc; i++) {
176			putp(st);
177			printf("%*s", (int)inc, "");
178		}
179		putp(st);
180	}
181	putp(cr);
182
183	exit(0);
184}
185
186static void
187usage(void)
188{
189
190	fprintf(stderr,
191"usage: tabs [-n|-a|-a2|-c|-c2|-c3|-f|-p|-s|-u] [+m[n]] [-T type]\n");
192	fprintf(stderr,
193"       tabs [-T type] [+[n]] n1,[n2,...]\n");
194	exit(1);
195}
196
197static void
198gettabs(char *arg, long stops[], long *nstops)
199{
200	char *tok, *end;
201	long last, stop;
202
203	for (last = *nstops = 0, tok = strtok(arg, ","); tok != NULL;
204	    tok = strtok(NULL, ",")) {
205		if (*nstops >= NSTOPS)
206			errx(1, "too many tab stops (limit %d)", NSTOPS);
207		errno = 0;
208		stop = strtol(tok, &end, 10);
209		if (errno != 0 || *end != '\0' || stop <= 0)
210			errx(1, "%s: invalid tab stop", tok);
211		if (*tok == '+') {
212			if (tok == arg)
213				errx(1, "%s: first tab may not be relative",
214				    tok);
215			stop += last;
216		}
217		if (last > stop)
218			errx(1, "cannot go backwards");
219		last = stops[(*nstops)++] = stop;
220	}
221}
222
223static int
224ttywidth(void)
225{
226	struct winsize ws;
227	int width;
228
229	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1)
230		width = ws.ws_col;
231	else if ((width = tgetnum("co")) == 0) {
232		width = 80;
233		warnx("cannot find terminal width; defaulted to %d", width);
234	}
235
236	return (width);
237}
238