lib/other/ttyslot.c

   1 /*
   2 ttyslot.c
   3
   4 Return the index in the utmp file for the current user's terminal. The
   5 current user's terminal is the first file descriptor in the range 0..2
   6 for which ttyname() returns a name. The index is the line number in the
   7 /etc/ttytab file. 0 will be returned in case of an error.
   8
   9 Created:        Oct 11, 1992 by Philip Homburg
  10 */
  11
  12 #define _MINIX_SOURCE
  13
  14 #include <sys/types.h>
  15 #include <ttyent.h>
  16 #include <string.h>
  17 #include <unistd.h>
  18
  19 int ttyslot()
  20 {
  21         int slot;
  22
  23         slot= fttyslot(0);
  24         if (slot == 0) slot= fttyslot(1);
  25         if (slot == 0) slot= fttyslot(2);
  26         return slot;
  27 }
  28
  29 int fttyslot(fd)
  30 int fd;
  31 {
  32         char *tname;
  33         int lineno;
  34         struct ttyent *ttyp;
  35
  36         tname= ttyname(fd);
  37         if (tname == NULL) return 0;
  38
  39         /* Assume that tty devices are in /dev */
  40         if (strncmp(tname, "/dev/", 5) != 0)
  41                 return 0;       /* Malformed tty name. */
  42         tname += 5;
  43
  44         /* Scan /etc/ttytab. */
  45         lineno= 1;
  46         while ((ttyp= getttyent()) != NULL)
  47         {
  48                 if (strcmp(tname, ttyp->ty_name) == 0)
  49                 {
  50                         endttyent();
  51                         return lineno;
  52                 }
  53                 lineno++;
  54         }
  55         /* No match */
  56         endttyent();
  57         return 0;
  58 }
  59
  60 /*
  61  * $PchHeader: /mount/hd2/minix/lib/misc/RCS/ttyslot.c,v 1.3 1994/12/22 13:49:12 philip Exp $
  62  */