term.c revision 241737
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 * 4. 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 30#include <sys/cdefs.h> 31 32__FBSDID("$FreeBSD: head/usr.bin/tset/term.c 241737 2012-10-19 14:49:42Z ed $"); 33 34#ifndef lint 35static const char sccsid[] = "@(#)term.c 8.1 (Berkeley) 6/9/93"; 36#endif 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 <termcap.h> 45#include <unistd.h> 46#include <ttyent.h> 47#include "extern.h" 48 49static char tbuf[1024]; /* Termcap entry. */ 50 51const char *askuser(const char *); 52char *ttys(char *); 53 54/* 55 * Figure out what kind of terminal we're dealing with, and then read in 56 * its termcap entry. 57 */ 58const char * 59get_termcap_entry(char *userarg, char **tcapbufp) 60{ 61 struct ttyent *t; 62 int rval; 63 char *p, *ttypath; 64 const char *ttype; 65 66 if (userarg) { 67 ttype = userarg; 68 goto found; 69 } 70 71 /* Try the environment. */ 72 if ((ttype = getenv("TERM"))) 73 goto map; 74 75 /* Try ttyname(3); check for dialup or other mapping. */ 76 if ((ttypath = ttyname(STDERR_FILENO))) { 77 if ((p = strrchr(ttypath, '/'))) 78 ++p; 79 else 80 p = ttypath; 81 if ((t = getttynam(p))) { 82 ttype = t->ty_type; 83 goto map; 84 } 85 } 86 87 /* If still undefined, use "unknown". */ 88 ttype = "unknown"; 89 90map: ttype = mapped(ttype); 91 92 /* 93 * If not a path, remove TERMCAP from the environment so we get a 94 * real entry from /etc/termcap. This prevents us from being fooled 95 * by out of date stuff in the environment. 96 */ 97found: if ((p = getenv("TERMCAP")) != NULL && *p != '/') 98 unsetenv("TERMCAP"); 99 100 /* 101 * ttype now contains a pointer to the type of the terminal. 102 * If the first character is '?', ask the user. 103 */ 104 if (ttype[0] == '?') { 105 if (ttype[1] != '\0') 106 ttype = askuser(ttype + 1); 107 else 108 ttype = askuser(NULL); 109 } 110 111 /* Find the termcap entry. If it doesn't exist, ask the user. */ 112 while ((rval = tgetent(tbuf, ttype)) == 0) { 113 warnx("terminal type %s is unknown", ttype); 114 ttype = askuser(NULL); 115 } 116 if (rval == -1) 117 errx(1, "termcap: %s", strerror(errno ? errno : ENOENT)); 118 *tcapbufp = tbuf; 119 return (ttype); 120} 121 122/* Prompt the user for a terminal type. */ 123const char * 124askuser(const char *dflt) 125{ 126 static char answer[256]; 127 char *p; 128 129 /* We can get recalled; if so, don't continue uselessly. */ 130 if (feof(stdin) || ferror(stdin)) { 131 (void)fprintf(stderr, "\n"); 132 exit(1); 133 } 134 for (;;) { 135 if (dflt) 136 (void)fprintf(stderr, "Terminal type? [%s] ", dflt); 137 else 138 (void)fprintf(stderr, "Terminal type? "); 139 (void)fflush(stderr); 140 141 if (fgets(answer, sizeof(answer), stdin) == NULL) { 142 if (dflt == NULL) { 143 (void)fprintf(stderr, "\n"); 144 exit(1); 145 } 146 return (dflt); 147 } 148 149 if ((p = strchr(answer, '\n'))) 150 *p = '\0'; 151 if (answer[0]) 152 return (answer); 153 if (dflt != NULL) 154 return (dflt); 155 } 156} 157