lib/libc/gen/ttyslot.c

   1 /*      $NetBSD: ttyslot.c,v 1.12.34.1 2008/11/08 21:45:38 christos Exp $       */
   2
   3 /*
   4  * Copyright (c) 1988, 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 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)ttyslot.c   8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: ttyslot.c,v 1.12.34.1 2008/11/08 21:45:38 christos Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42 #include <ttyent.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47 #include <sys/ioctl.h>
  48 #include <sys/stat.h>
  49
  50 #ifdef __weak_alias
  51 __weak_alias(ttyslot,_ttyslot)
  52 #endif
  53
  54 int
  55 ttyslot(void)
  56 {
  57         struct ttyent *ttyp;
  58         int slot = 0, ispty = 0;
  59         char *p;
  60         int cnt;
  61         char *name;
  62         struct ptmget ptm;
  63
  64         setttyent();
  65         for (cnt = 0; cnt < 3; ++cnt) {
  66                 if (ioctl(cnt, TIOCPTSNAME, &ptm) != -1) {
  67                         ispty = 1;
  68                         name = ptm.sn;
  69                 } else if ((name = ttyname(cnt)) != NULL) {
  70                         ispty = 0;
  71                 } else
  72                         continue;
  73
  74                 if ((p = strstr(name, "/pts/")) != NULL)
  75                         ++p;
  76                 else if ((p = strrchr(name, '/')) != NULL)
  77                         ++p;
  78                 else
  79                         p = name;
  80
  81                 for (slot = 1; (ttyp = getttyent()) != NULL; ++slot)
  82                         if (!strcmp(ttyp->ty_name, p)) {
  83                                 endttyent();
  84                                 return slot;
  85                         }
  86                 break;
  87         }
  88         endttyent();
  89         if (ispty) {
  90                 struct stat st;
  91                 if (fstat(cnt, &st) == -1)
  92                         return 0;
  93                 return slot + (int)minor(st.st_rdev) + 1;
  94         }
  95         return 0;
  96 }