move entry/exit debugging to 21.1

[unix-history] / usr / src / usr.bin / tty / tty.c

/*
* Copyright (c) 1988, 1993
*      The Regents of the University of California.  All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1988, 1993\n\
       The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)tty.c       8.1 (Berkeley) %G%";
#endif /* not lint */

#include <stdio.h>

main(argc, argv)
       int argc;
       char **argv;
{
       int ch, sflag;
       char *t, *ttyname();

       sflag = 0;
       while ((ch = getopt(argc, argv, "s")) != EOF)
               switch((char)ch) {
               case 's':
                       sflag = 1;
                       break;
               case '?':
               default:
                       fputs("usage: tty [-s]\n", stderr);
                       exit(2);
               }

       t = ttyname(0);
       if (!sflag)
               puts(t ? t : "not a tty");
       exit(t ? 0 : 1);
}