NAME

       posix_openpt — open a pseudo-terminal device

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <fcntl.h>
       #include <stdlib.h>

       int
       posix_openpt(int oflag);

DESCRIPTION

       The  posix_openpt() function allocates a new pseudo-terminal and establishes a connection with its master
       device.  A slave device shall be created in /dev/pts.  After the pseudo-terminal has been allocated,  the
       slave  device should have the proper permissions before it can be used (see grantpt(3)).  The name of the
       slave device can be determined by calling ptsname(3).

       The file status flags and file access modes of the open file description shall be set  according  to  the
       value  of  oflag.  Values for oflag are constructed by a bitwise-inclusive OR of flags from the following
       list, defined in <fcntl.h>:

       O_RDWR     Open for reading and writing.

       O_NOCTTY   If set posix_openpt() shall not cause the terminal device to become the  controlling  terminal
                  for the process.

       O_CLOEXEC  Set the close-on-exec flag for the new file descriptor.

       The posix_openpt() function shall fail when oflag contains other values.

RETURN VALUES

       Upon  successful  completion, the posix_openpt() function shall allocate a new pseudo-terminal device and
       return a non-negative integer representing a file descriptor, which is connected to  its  master  device.
       Otherwise, -1 shall be returned and errno set to indicate the error.

ERRORS

       The posix_openpt() function shall fail if:

       [ENFILE]           The system file table is full.

       [EINVAL]           The value of oflag is not valid.

       [EAGAIN]           Out of pseudo-terminal resources.

SEE ALSO

       ptsname(3), pts(4), tty(4)

STANDARDS

       The  posix_openpt()  function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).  The ability to use O_CLOEXEC
       is an extension to the standard.

HISTORY

       The posix_openpt() function appeared in FreeBSD 5.0.  In FreeBSD 8.0, this  function  was  changed  to  a
       system call.

NOTES

       The  flag  O_NOCTTY  is  included  for compatibility; in FreeBSD, opening a terminal does not cause it to
       become a process's controlling terminal.

AUTHORS

       Ed Schouten <ed@FreeBSD.org>

Debian                                         September 21, 2016                                POSIX_OPENPT(2)