| POSIX_OPENPT(3) | Library Functions Manual | POSIX_OPENPT(3) | 
posix_openpt —
#include <stdlib.h>
#include <fcntl.h>
int
  
  posix_openpt(int
    oflag);
posix_openpt() function searches for an unused
  master pseudo-terminal device, opens it, and returns a file descriptor
  associated with the now used pseudo-terminal device. The
  oflag argument has the same meaning as in the
  open(2) call.
posix_openpt() returns a non-negative
  integer, which corresponds to a file descriptor pointing to the master
  pseudo-terminal device. Otherwise, a value of -1 is returned and
  errno is set to indicate the error.
Note that unlike implementations on some other operating systems,
    posix_openpt() does not return
    EINVAL if a flag supplied in
    oflag would be deemed invalid, instead it is simply
    ignored. This means it is not possible to dynamically test which
    open(2) flags are possible to
    set, and apply a fallback if EINVAL is received.
    However, this is unlikely to be a concern in practice, as flags such as
    O_NONBLOCK and O_CLOEXEC are
    supported.
	int
	posix_openpt(int oflag) {
		return open("/dev/ptmx", oflag);
	}
posix_openpt() function conforms to
  IEEE Std 1003.1-2001 (“POSIX.1”).
| November 15, 2022 | NetBSD 10.0 |