1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33
34 __FBSDID("$FreeBSD$");
35
36 #ifndef lint
37 static const char sccsid[] = "@(#)term.c 8.1 (Berkeley) 6/9/93";
38 #endif
39
40 #include <sys/types.h>
41 #include <err.h>
42 #include <errno.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <termcap.h>
47 #include <unistd.h>
48 #include <ttyent.h>
49 #include "extern.h"
50
51 static char tbuf[1024]; /* Termcap entry. */
52
53 const char *askuser(const char *);
54 char *ttys(char *);
55
56 /*
57 * Figure out what kind of terminal we're dealing with, and then read in
58 * its termcap entry.
59 */
60 const char *
get_termcap_entry(char * userarg,char ** tcapbufp)61 get_termcap_entry(char *userarg, char **tcapbufp)
62 {
63 struct ttyent *t;
64 int rval;
65 char *p, *ttypath;
66 const char *ttype;
67
68 if (userarg) {
69 ttype = userarg;
70 goto found;
71 }
72
73 /* Try the environment. */
74 if ((ttype = getenv("TERM")))
75 goto map;
76
77 /* Try ttyname(3); check for dialup or other mapping. */
78 if ((ttypath = ttyname(STDERR_FILENO))) {
79 if ((p = strrchr(ttypath, '/')))
80 ++p;
81 else
82 p = ttypath;
83 if ((t = getttynam(p))) {
84 ttype = t->ty_type;
85 goto map;
86 }
87 }
88
89 /* If still undefined, use "unknown". */
90 ttype = "unknown";
91
92 map: ttype = mapped(ttype);
93
94 /*
95 * If not a path, remove TERMCAP from the environment so we get a
96 * real entry from /etc/termcap. This prevents us from being fooled
97 * by out of date stuff in the environment.
98 */
99 found: if ((p = getenv("TERMCAP")) != NULL && *p != '/')
100 unsetenv("TERMCAP");
101
102 /*
103 * ttype now contains a pointer to the type of the terminal.
104 * If the first character is '?', ask the user.
105 */
106 if (ttype[0] == '?') {
107 if (ttype[1] != '\0')
108 ttype = askuser(ttype + 1);
109 else
110 ttype = askuser(NULL);
111 }
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. */
125 const char *
askuser(const char * dflt)126 askuser(const char *dflt)
127 {
128 static char answer[256];
129 char *p;
130
131 /* We can get recalled; if so, don't continue uselessly. */
132 if (feof(stdin) || ferror(stdin)) {
133 (void)fprintf(stderr, "\n");
134 exit(1);
135 }
136 for (;;) {
137 if (dflt)
138 (void)fprintf(stderr, "Terminal type? [%s] ", dflt);
139 else
140 (void)fprintf(stderr, "Terminal type? ");
141 (void)fflush(stderr);
142
143 if (fgets(answer, sizeof(answer), stdin) == NULL) {
144 if (dflt == NULL) {
145 (void)fprintf(stderr, "\n");
146 exit(1);
147 }
148 return (dflt);
149 }
150
151 if ((p = strchr(answer, '\n')))
152 *p = '\0';
153 if (answer[0])
154 return (answer);
155 if (dflt != NULL)
156 return (dflt);
157 }
158 }
159