xref: /dragonfly/usr.bin/tset/term.c (revision a68e0df0)
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  * @(#)term.c	8.1 (Berkeley) 6/9/93
34  * $FreeBSD: src/usr.bin/tset/term.c,v 1.4 1999/08/28 01:06:58 peter Exp $
35  * $DragonFly: src/usr.bin/tset/term.c,v 1.4 2004/08/30 18:06:50 eirikn Exp $
36  */
37 
38 #include <sys/types.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <ttyent.h>
46 #include "extern.h"
47 
48 char    tbuf[1024];      		/* Termcap entry. */
49 
50 const char *askuser(const char *);
51 char	*ttys(char *);
52 
53 /*
54  * Figure out what kind of terminal we're dealing with, and then read in
55  * its termcap entry.
56  */
57 const char *
58 get_termcap_entry(char *userarg, char **tcapbufp)
59 {
60 	struct ttyent *t;
61 	int rval;
62 	char *p, *ttypath;
63 	const char *ttype;
64 
65 	if (userarg) {
66 		ttype = userarg;
67 		goto found;
68 	}
69 
70 	/* Try the environment. */
71 	if ((ttype = getenv("TERM")))
72 		goto map;
73 
74 	/* Try ttyname(3); check for dialup or other mapping. */
75 	if ((ttypath = ttyname(STDERR_FILENO))) {
76 		if ((p = strrchr(ttypath, '/')))
77 			++p;
78 		else
79 			p = ttypath;
80 		if ((t = getttynam(p))) {
81 			ttype = t->ty_type;
82 			goto map;
83 		}
84 	}
85 
86 	/* If still undefined, use "unknown". */
87 	ttype = "unknown";
88 
89 map:	ttype = mapped(ttype);
90 
91 	/*
92 	 * If not a path, remove TERMCAP from the environment so we get a
93 	 * real entry from /etc/termcap.  This prevents us from being fooled
94 	 * by out of date stuff in the environment.
95 	 */
96 found:	if ((p = getenv("TERMCAP")) != NULL && *p != '/')
97 		unsetenv("TERMCAP");
98 
99 	/*
100 	 * ttype now contains a pointer to the type of the terminal.
101 	 * If the first character is '?', ask the user.
102 	 */
103 	if (ttype[0] == '?') {
104 		if (ttype[1] != '\0')
105 			ttype = askuser(ttype + 1);
106 		else
107 			ttype = askuser(NULL);
108 	}
109 
110 	/* Find the termcap entry.  If it doesn't exist, ask the user. */
111 	while ((rval = tgetent(tbuf, ttype)) == 0) {
112 		warnx("terminal type %s is unknown", ttype);
113 		ttype = askuser(NULL);
114 	}
115 	if (rval == -1)
116 		errx(1, "termcap: %s", strerror(errno ? errno : ENOENT));
117 	*tcapbufp = tbuf;
118 	return (ttype);
119 }
120 
121 /* Prompt the user for a terminal type. */
122 const char *
123 askuser(const char *dflt)
124 {
125 	static char answer[256];
126 	char *p;
127 
128 	/* We can get recalled; if so, don't continue uselessly. */
129 	if (feof(stdin) || ferror(stdin)) {
130 		(void)fprintf(stderr, "\n");
131 		exit(1);
132 	}
133 	for (;;) {
134 		if (dflt)
135 			(void)fprintf(stderr, "Terminal type? [%s] ", dflt);
136 		else
137 			(void)fprintf(stderr, "Terminal type? ");
138 		(void)fflush(stderr);
139 
140 		if (fgets(answer, sizeof(answer), stdin) == NULL) {
141 			if (dflt == NULL) {
142 				(void)fprintf(stderr, "\n");
143 				exit(1);
144 			}
145 			return (dflt);
146 		}
147 
148 		if ((p = strchr(answer, '\n')))
149 			*p = '\0';
150 		if (answer[0])
151 			return (answer);
152 		if (dflt != NULL)
153 			return (dflt);
154 	}
155 }
156