bin/ksh/tty.c

   1 /*      $OpenBSD: tty.c,v 1.9 2006/03/14 22:08:01 deraadt Exp $ */
   2
   3 #include "sh.h"
   4 #include <sys/stat.h>
   5 #define EXTERN
   6 #include "tty.h"
   7 #undef EXTERN
   8
   9 /* Initialize tty_fd.  Used for saving/reseting tty modes upon
  10  * foreground job completion and for setting up tty process group.
  11  */
  12 void
  13 tty_init(int init_ttystate)
  14 {
  15         int     do_close = 1;
  16         int     tfd;
  17
  18         if (tty_fd >= 0) {
  19                 close(tty_fd);
  20                 tty_fd = -1;
  21         }
  22         tty_devtty = 1;
  23
  24         if ((tfd = open("/dev/tty", O_RDWR, 0)) < 0) {
  25                 tty_devtty = 0;
  26                 warningf(false, "No controlling tty (open /dev/tty: %s)",
  27                     strerror(errno));
  28         }
  29
  30         if (tfd < 0) {
  31                 do_close = 0;
  32                 if (isatty(0))
  33                         tfd = 0;
  34                 else if (isatty(2))
  35                         tfd = 2;
  36                 else {
  37                         warningf(false, "Can't find tty file descriptor");
  38                         return;
  39                 }
  40         }
  41         if ((tty_fd = fcntl(tfd, F_DUPFD, FDBASE)) < 0) {
  42                 warningf(false, "j_ttyinit: dup of tty fd failed: %s",
  43                     strerror(errno));
  44         } else if (fcntl(tty_fd, F_SETFD, FD_CLOEXEC) < 0) {
  45                 warningf(false, "j_ttyinit: can't set close-on-exec flag: %s",
  46                     strerror(errno));
  47                 close(tty_fd);
  48                 tty_fd = -1;
  49         } else if (init_ttystate)
  50                 tcgetattr(tty_fd, &tty_state);
  51         if (do_close)
  52                 close(tfd);
  53 }
  54
  55 void
  56 tty_close(void)
  57 {
  58         if (tty_fd >= 0) {
  59                 close(tty_fd);
  60                 tty_fd = -1;
  61         }
  62 }