xref: /dragonfly/usr.bin/tset/term.c (revision 37de577a)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)term.c	8.1 (Berkeley) 6/9/93
30  * $FreeBSD: src/usr.bin/tset/term.c,v 1.4 1999/08/28 01:06:58 peter Exp $
31  * $DragonFly: src/usr.bin/tset/term.c,v 1.4 2004/08/30 18:06:50 eirikn Exp $
32  */
33 
34 #include <sys/types.h>
35 #include <err.h>
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41 #include <ttyent.h>
42 #include "extern.h"
43 
44 char    tbuf[1024];      		/* Termcap entry. */
45 
46 const char *askuser(const char *);
47 char	*ttys(char *);
48 
49 /*
50  * Figure out what kind of terminal we're dealing with, and then read in
51  * its termcap entry.
52  */
53 const char *
54 get_termcap_entry(char *userarg, char **tcapbufp)
55 {
56 	struct ttyent *t;
57 	int rval;
58 	char *p, *ttypath;
59 	const char *ttype;
60 
61 	if (userarg) {
62 		ttype = userarg;
63 		goto found;
64 	}
65 
66 	/* Try the environment. */
67 	if ((ttype = getenv("TERM")))
68 		goto map;
69 
70 	/* Try ttyname(3); check for dialup or other mapping. */
71 	if ((ttypath = ttyname(STDERR_FILENO))) {
72 		if ((p = strrchr(ttypath, '/')))
73 			++p;
74 		else
75 			p = ttypath;
76 		if ((t = getttynam(p))) {
77 			ttype = t->ty_type;
78 			goto map;
79 		}
80 	}
81 
82 	/* If still undefined, use "unknown". */
83 	ttype = "unknown";
84 
85 map:	ttype = mapped(ttype);
86 
87 	/*
88 	 * If not a path, remove TERMCAP from the environment so we get a
89 	 * real entry from /etc/termcap.  This prevents us from being fooled
90 	 * by out of date stuff in the environment.
91 	 */
92 found:	if ((p = getenv("TERMCAP")) != NULL && *p != '/')
93 		unsetenv("TERMCAP");
94 
95 	/*
96 	 * ttype now contains a pointer to the type of the terminal.
97 	 * If the first character is '?', ask the user.
98 	 */
99 	if (ttype[0] == '?') {
100 		if (ttype[1] != '\0')
101 			ttype = askuser(ttype + 1);
102 		else
103 			ttype = askuser(NULL);
104 	}
105 
106 	/* Find the termcap entry.  If it doesn't exist, ask the user. */
107 	while ((rval = tgetent(tbuf, ttype)) == 0) {
108 		warnx("terminal type %s is unknown", ttype);
109 		ttype = askuser(NULL);
110 	}
111 	if (rval == -1)
112 		errx(1, "termcap: %s", strerror(errno ? errno : ENOENT));
113 	*tcapbufp = tbuf;
114 	return (ttype);
115 }
116 
117 /* Prompt the user for a terminal type. */
118 const char *
119 askuser(const char *dflt)
120 {
121 	static char answer[256];
122 	char *p;
123 
124 	/* We can get recalled; if so, don't continue uselessly. */
125 	if (feof(stdin) || ferror(stdin)) {
126 		(void)fprintf(stderr, "\n");
127 		exit(1);
128 	}
129 	for (;;) {
130 		if (dflt)
131 			(void)fprintf(stderr, "Terminal type? [%s] ", dflt);
132 		else
133 			(void)fprintf(stderr, "Terminal type? ");
134 		(void)fflush(stderr);
135 
136 		if (fgets(answer, sizeof(answer), stdin) == NULL) {
137 			if (dflt == NULL) {
138 				(void)fprintf(stderr, "\n");
139 				exit(1);
140 			}
141 			return (dflt);
142 		}
143 
144 		if ((p = strchr(answer, '\n')))
145 			*p = '\0';
146 		if (answer[0])
147 			return (answer);
148 		if (dflt != NULL)
149 			return (dflt);
150 	}
151 }
152