term.c revision 200419 
1/*-
2 * Copyright (c) 1991, 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: head/usr.bin/tset/term.c 200419 2009-12-11 23:30:22Z delphij $");
37
38#ifndef lint
39static const char sccsid[] = "@(#)term.c	8.1 (Berkeley) 6/9/93";
40#endif
41
42#include <sys/types.h>
43#include <err.h>
44#include <errno.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48#include <termcap.h>
49#include <unistd.h>
50#include <ttyent.h>
51#include "extern.h"
52
53char    tbuf[1024];      		/* Termcap entry. */
54
55const char *askuser(const char *);
56char	*ttys(char *);
57
58/*
59 * Figure out what kind of terminal we're dealing with, and then read in
60 * its termcap entry.
61 */
62const char *
63get_termcap_entry(char *userarg, char **tcapbufp)
64{
65	struct ttyent *t;
66	int rval;
67	char *p, *ttypath;
68	const char *ttype;
69
70	if (userarg) {
71		ttype = userarg;
72		goto found;
73	}
74
75	/* Try the environment. */
76	if ((ttype = getenv("TERM")))
77		goto map;
78
79	/* Try ttyname(3); check for dialup or other mapping. */
80	if ((ttypath = ttyname(STDERR_FILENO))) {
81		if ((p = rindex(ttypath, '/')))
82			++p;
83		else
84			p = ttypath;
85		if ((t = getttynam(p))) {
86			ttype = t->ty_type;
87			goto map;
88		}
89	}
90
91	/* If still undefined, use "unknown". */
92	ttype = "unknown";
93
94map:	ttype = mapped(ttype);
95
96	/*
97	 * If not a path, remove TERMCAP from the environment so we get a
98	 * real entry from /etc/termcap.  This prevents us from being fooled
99	 * by out of date stuff in the environment.
100	 */
101found:	if ((p = getenv("TERMCAP")) != NULL && *p != '/')
102		unsetenv("TERMCAP");
103
104	/*
105	 * ttype now contains a pointer to the type of the terminal.
106	 * If the first character is '?', ask the user.
107	 */
108	if (ttype[0] == '?') {
109		if (ttype[1] != '\0')
110			ttype = askuser(ttype + 1);
111		else
112			ttype = askuser(NULL);
113	}
114
115	/* Find the termcap entry.  If it doesn't exist, ask the user. */
116	while ((rval = tgetent(tbuf, ttype)) == 0) {
117		warnx("terminal type %s is unknown", ttype);
118		ttype = askuser(NULL);
119	}
120	if (rval == -1)
121		errx(1, "termcap: %s", strerror(errno ? errno : ENOENT));
122	*tcapbufp = tbuf;
123	return (ttype);
124}
125
126/* Prompt the user for a terminal type. */
127const char *
128askuser(const char *dflt)
129{
130	static char answer[256];
131	char *p;
132
133	/* We can get recalled; if so, don't continue uselessly. */
134	if (feof(stdin) || ferror(stdin)) {
135		(void)fprintf(stderr, "\n");
136		exit(1);
137	}
138	for (;;) {
139		if (dflt)
140			(void)fprintf(stderr, "Terminal type? [%s] ", dflt);
141		else
142			(void)fprintf(stderr, "Terminal type? ");
143		(void)fflush(stderr);
144
145		if (fgets(answer, sizeof(answer), stdin) == NULL) {
146			if (dflt == NULL) {
147				(void)fprintf(stderr, "\n");
148				exit(1);
149			}
150			return (dflt);
151		}
152
153		if ((p = index(answer, '\n')))
154			*p = '\0';
155		if (answer[0])
156			return (answer);
157		if (dflt != NULL)
158			return (dflt);
159	}
160}
161