login/forkpty.c

   1 /* Copyright (C) 1998-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sys/types.h>
  20 #include <termios.h>
  21 #include <unistd.h>
  22 #include <utmp.h>
  23 #include <pty.h>
  24
  25 int
  26 forkpty (int *amaster, char *name, const struct termios *termp,
  27          const struct winsize *winp)
  28 {
  29   int master, slave, pid;
  30
  31   if (openpty (&master, &slave, name, termp, winp) == -1)
  32     return -1;
  33
  34   switch (pid = fork ())
  35     {
  36     case -1:
  37       close (master);
  38       close (slave);
  39       return -1;
  40     case 0:
  41       /* Child.  */
  42       close (master);
  43       if (login_tty (slave))
  44         _exit (1);
  45
  46       return 0;
  47     default:
  48       /* Parent.  */
  49       *amaster = master;
  50       close (slave);
  51
  52       return pid;
  53     }
  54 }