term.c revision 28370 
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#ifndef lint
35#if 0
36static char sccsid[] = "@(#)term.c	8.1 (Berkeley) 6/9/93";
37#endif
38static const char rcsid[] =
39	"$Id$";
40#endif /* not lint */
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 <unistd.h>
49#include <ttyent.h>
50#include "extern.h"
51
52char    tbuf[1024];      		/* Termcap entry. */
53
54char	*askuser __P((char *));
55char	*ttys __P((char *));
56
57/*
58 * Figure out what kind of terminal we're dealing with, and then read in
59 * its termcap entry.
60 */
61char *
62get_termcap_entry(userarg, tcapbufp)
63	char *userarg, **tcapbufp;
64{
65	struct ttyent *t;
66	int rval;
67	char *p, *ttype, *ttypath;
68
69	if (userarg) {
70		ttype = userarg;
71		goto found;
72	}
73
74	/* Try the environment. */
75	if ((ttype = getenv("TERM")))
76		goto map;
77
78	/* Try ttyname(3); check for dialup or other mapping. */
79	if ((ttypath = ttyname(STDERR_FILENO))) {
80		if ((p = rindex(ttypath, '/')))
81			++p;
82		else
83			p = ttypath;
84		if ((t = getttynam(p))) {
85			ttype = t->ty_type;
86			goto map;
87		}
88	}
89
90	/* If still undefined, use "unknown". */
91	ttype = "unknown";
92
93map:	ttype = mapped(ttype);
94
95	/*
96	 * If not a path, remove TERMCAP from the environment so we get a
97	 * real entry from /etc/termcap.  This prevents us from being fooled
98	 * by out of date stuff in the environment.
99	 */
100found:	if ((p = getenv("TERMCAP")) != NULL && *p != '/')
101		unsetenv("TERMCAP");
102
103	/*
104	 * ttype now contains a pointer to the type of the terminal.
105	 * If the first character is '?', ask the user.
106	 */
107	if (ttype[0] == '?')
108		if (ttype[1] != '\0')
109			ttype = askuser(ttype + 1);
110		else
111			ttype = askuser(NULL);
112
113	/* Find the termcap entry.  If it doesn't exist, ask the user. */
114	while ((rval = tgetent(tbuf, ttype)) == 0) {
115		warnx("terminal type %s is unknown", ttype);
116		ttype = askuser(NULL);
117	}
118	if (rval == -1)
119		errx(1, "termcap: %s", strerror(errno ? errno : ENOENT));
120	*tcapbufp = tbuf;
121	return (ttype);
122}
123
124/* Prompt the user for a terminal type. */
125char *
126askuser(dflt)
127	char *dflt;
128{
129	static char answer[256];
130	char *p;
131
132	/* We can get recalled; if so, don't continue uselessly. */
133	if (feof(stdin) || ferror(stdin)) {
134		(void)fprintf(stderr, "\n");
135		exit(1);
136	}
137	for (;;) {
138		if (dflt)
139			(void)fprintf(stderr, "Terminal type? [%s] ", dflt);
140		else
141			(void)fprintf(stderr, "Terminal type? ");
142		(void)fflush(stderr);
143
144		if (fgets(answer, sizeof(answer), stdin) == NULL) {
145			if (dflt == NULL) {
146				(void)fprintf(stderr, "\n");
147				exit(1);
148			}
149			return (dflt);
150		}
151
152		if ((p = index(answer, '\n')))
153			*p = '\0';
154		if (answer[0])
155			return (answer);
156		if (dflt != NULL)
157			return (dflt);
158	}
159}
160