xref: /original-bsd/usr.bin/tset/term.c (revision 04dd0305)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 static char sccsid[] = "@(#)term.c	8.1 (Berkeley) 06/09/93";
10 #endif /* not lint */
11 
12 #include <sys/types.h>
13 #include <errno.h>
14 #include <ttyent.h>
15 #include <unistd.h>
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <string.h>
19 #include "extern.h"
20 
21 char    tbuf[1024];      		/* Termcap entry. */
22 
23 char	*askuser __P((char *));
24 char	*ttys __P((char *));
25 
26 /*
27  * Figure out what kind of terminal we're dealing with, and then read in
28  * its termcap entry.
29  */
30 char *
31 get_termcap_entry(userarg, tcapbufp)
32 	char *userarg, **tcapbufp;
33 {
34 	struct ttyent *t;
35 	int rval;
36 	char *p, *ttype, *ttypath;
37 
38 	if (userarg) {
39 		ttype = userarg;
40 		goto found;
41 	}
42 
43 	/* Try the environment. */
44 	if (ttype = getenv("TERM"))
45 		goto map;
46 
47 	/* Try ttyname(3); check for dialup or other mapping. */
48 	if (ttypath = ttyname(STDERR_FILENO)) {
49 		if (p = rindex(ttypath, '/'))
50 			++p;
51 		else
52 			p = ttypath;
53 		if ((t = getttynam(p))) {
54 			ttype = t->ty_type;
55 			goto map;
56 		}
57 	}
58 
59 	/* If still undefined, use "unknown". */
60 	ttype = "unknown";
61 
62 map:	ttype = mapped(ttype);
63 
64 	/*
65 	 * If not a path, remove TERMCAP from the environment so we get a
66 	 * real entry from /etc/termcap.  This prevents us from being fooled
67 	 * by out of date stuff in the environment.
68 	 */
69 found:	if ((p = getenv("TERMCAP")) != NULL && *p != '/')
70 		unsetenv("TERMCAP");
71 
72 	/*
73 	 * ttype now contains a pointer to the type of the terminal.
74 	 * If the first character is '?', ask the user.
75 	 */
76 	if (ttype[0] == '?')
77 		if (ttype[1] != '\0')
78 			ttype = askuser(ttype + 1);
79 		else
80 			ttype = askuser(NULL);
81 
82 	/* Find the termcap entry.  If it doesn't exist, ask the user. */
83 	while ((rval = tgetent(tbuf, ttype)) == 0) {
84 		(void)fprintf(stderr,
85 		    "tset: terminal type %s is unknown\n", ttype);
86 		ttype = askuser(NULL);
87 	}
88 	if (rval == -1)
89 		err("termcap: %s", strerror(errno ? errno : ENOENT));
90 	*tcapbufp = tbuf;
91 	return (ttype);
92 }
93 
94 /* Prompt the user for a terminal type. */
95 char *
96 askuser(dflt)
97 	char *dflt;
98 {
99 	static char answer[256];
100 	char *p;
101 
102 	/* We can get recalled; if so, don't continue uselessly. */
103 	if (feof(stdin) || ferror(stdin)) {
104 		(void)fprintf(stderr, "\n");
105 		exit(1);
106 	}
107 	for (;;) {
108 		if (dflt)
109 			(void)fprintf(stderr, "Terminal type? [%s] ", dflt);
110 		else
111 			(void)fprintf(stderr, "Terminal type? ");
112 		(void)fflush(stderr);
113 
114 		if (fgets(answer, sizeof(answer), stdin) == NULL) {
115 			if (dflt == NULL) {
116 				(void)fprintf(stderr, "\n");
117 				exit(1);
118 			}
119 			return (dflt);
120 		}
121 
122 		if (p = index(answer, '\n'))
123 			*p = '\0';
124 		if (answer[0])
125 			return (answer);
126 		if (dflt != NULL)
127 			return (dflt);
128 	}
129 }
130