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. 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 }