posix_openpt
—
open a pseudo-terminal device
Standard C Library (libc, -lc)
The 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.
If successful, 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.
The standards committee did not want to directly expose the cloning device, thus
decided to wrap the functionality in this function. The equivalent code would
be:
int
posix_openpt(int oflag) {
return open("/dev/ptmx", oflag);
}
The posix_openpt
() function conforms to
IEEE Std 1003.1-2001 (“POSIX.1”).