xref: /netbsd-src/usr.bin/tset/term.c (revision 811e6386f8c5e4a3521c7003da29ec8673e344fa)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
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  * 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 static char sccsid[] = "@(#)term.c	5.1 (Berkeley) 12/22/91";
36 #endif /* not lint */
37 
38 #include <sys/types.h>
39 #include <errno.h>
40 #include <ttyent.h>
41 #include <unistd.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include "extern.h"
46 
47 char    tbuf[1024];      		/* Termcap entry. */
48 
49 char	*askuser __P((char *));
50 char	*ttys __P((char *));
51 
52 /*
53  * Figure out what kind of terminal we're dealing with, and then read in
54  * its termcap entry.
55  */
56 char *
57 get_termcap_entry(userarg, tcapbufp)
58 	char *userarg, **tcapbufp;
59 {
60 	struct ttyent *t;
61 	int rval;
62 	char *base, *ttype, *ttypath;
63 
64 	if (userarg) {
65 		ttype = userarg;
66 		goto found;
67 	}
68 
69 	/* Try the environment. */
70 	if (ttype = getenv("TERM"))
71 		goto map;
72 
73 	/* Try ttyname(3); check for dialup or other mapping. */
74 	if (ttypath = ttyname(STDERR_FILENO)) {
75 		if (base = rindex(ttypath, '/'))
76 			++base;
77 		else
78 			base = ttypath;
79 		if ((t = getttynam(base))) {
80 			ttype = t->ty_type;
81 			goto map;
82 		}
83 	}
84 
85 	/* If still undefined, use "unknown". */
86 	ttype = "unknown";
87 
88 map:	ttype = mapped(ttype);
89 
90 	/*
91 	 * Remove TERMCAP from the environment so we get a real entry from
92 	 * /etc/termcap.  This prevents us from being fooled by out of date
93 	 * stuff in the environment.
94 	 */
95 found:	unsetenv("TERMCAP");
96 
97 	/*
98 	 * ttype now contains a pointer to the type of the terminal.
99 	 * If the first character is '?', ask the user.
100 	 */
101 	if (ttype[0] == '?')
102 		ttype = askuser(ttype + 1);
103 
104 	/* Find the termcap entry.  If it doesn't exist, ask the user. */
105 	while ((rval = tgetent(tbuf, ttype)) == 0) {
106 		(void)fprintf(stderr,
107 		    "tset: terminal type %s is unknown\n", ttype);
108 		ttype = askuser(NULL);
109 	}
110 	if (rval == -1)
111 		err("termcap: %s", strerror(errno ? errno : ENOENT));
112 	*tcapbufp = tbuf;
113 	return (ttype);
114 }
115 
116 /* Prompt the user for a terminal type. */
117 char *
118 askuser(dflt)
119 	char *dflt;
120 {
121 	static char answer[256];
122 	char *p;
123 
124 	for (;;) {
125 		if (dflt)
126 			(void)fprintf(stderr, "Terminal type? [%s] ", dflt);
127 		else
128 			(void)fprintf(stderr, "Terminal type? ");
129 		(void)fflush(stderr);
130 
131 		if (fgets(answer, sizeof(answer), stdin) == NULL) {
132 			if (feof(stdin))
133 				clearerr(stdin);
134 			continue;
135 		}
136 
137 		if (p = index(answer, '\n'))
138 			*p = '\0';
139 		return (answer[0] ? answer : dflt);
140 	}
141 }
142