usr.bin/tset/term.c

   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. 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  * @(#)term.c   8.1 (Berkeley) 6/9/93
  34  * $FreeBSD: src/usr.bin/tset/term.c,v 1.4 1999/08/28 01:06:58 peter Exp $
  35  * $DragonFly: src/usr.bin/tset/term.c,v 1.4 2004/08/30 18:06:50 eirikn Exp $
  36  */
  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 <unistd.h>
  45 #include <ttyent.h>
  46 #include "extern.h"
  47
  48 char    tbuf[1024];                     /* Termcap entry. */
  49
  50 char    *askuser(char *);
  51 char    *ttys(char *);
  52
  53 /*
  54  * Figure out what kind of terminal we're dealing with, and then read in
  55  * its termcap entry.
  56  */
  57 char *
  58 get_termcap_entry(char *userarg, char **tcapbufp)
  59 {
  60         struct ttyent *t;
  61         int rval;
  62         char *p, *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 ((p = strrchr(ttypath, '/')))
  76                         ++p;
  77                 else
  78                         p = ttypath;
  79                 if ((t = getttynam(p))) {
  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          * If not a path, remove TERMCAP from the environment so we get a
  92          * real entry from /etc/termcap.  This prevents us from being fooled
  93          * by out of date stuff in the environment.
  94          */
  95 found:  if ((p = getenv("TERMCAP")) != NULL && *p != '/')
  96                 unsetenv("TERMCAP");
  97
  98         /*
  99          * ttype now contains a pointer to the type of the terminal.
 100          * If the first character is '?', ask the user.
 101          */
 102         if (ttype[0] == '?') {
 103                 if (ttype[1] != '\0')
 104                         ttype = askuser(ttype + 1);
 105                 else
 106                         ttype = askuser(NULL);
 107         }
 108
 109         /* Find the termcap entry.  If it doesn't exist, ask the user. */
 110         while ((rval = tgetent(tbuf, ttype)) == 0) {
 111                 warnx("terminal type %s is unknown", ttype);
 112                 ttype = askuser(NULL);
 113         }
 114         if (rval == -1)
 115                 errx(1, "termcap: %s", strerror(errno ? errno : ENOENT));
 116         *tcapbufp = tbuf;
 117         return (ttype);
 118 }
 119
 120 /* Prompt the user for a terminal type. */
 121 char *
 122 askuser(char *dflt)
 123 {
 124         static char answer[256];
 125         char *p;
 126
 127         /* We can get recalled; if so, don't continue uselessly. */
 128         if (feof(stdin) || ferror(stdin)) {
 129                 (void)fprintf(stderr, "\n");
 130                 exit(1);
 131         }
 132         for (;;) {
 133                 if (dflt)
 134                         (void)fprintf(stderr, "Terminal type? [%s] ", dflt);
 135                 else
 136                         (void)fprintf(stderr, "Terminal type? ");
 137                 (void)fflush(stderr);
 138
 139                 if (fgets(answer, sizeof(answer), stdin) == NULL) {
 140                         if (dflt == NULL) {
 141                                 (void)fprintf(stderr, "\n");
 142                                 exit(1);
 143                         }
 144                         return (dflt);
 145                 }
 146
 147                 if ((p = strchr(answer, '\n')))
 148                         *p = '\0';
 149                 if (answer[0])
 150                         return (answer);
 151                 if (dflt != NULL)
 152                         return (dflt);
 153         }
 154 }