NAME

posix_openpt — open a pseudo-terminal device

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

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

int
posix_openpt(int oflag);

DESCRIPTION

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.

RETURN VALUES

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.

SEE ALSO

ioctl(2), open(2), grantpt(3), ptsname(3), unlockpt(3)

RATIONALE

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); 
	}

STANDARDS

The posix_openpt() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).