POSIX_OPENPT(3) Linux Programmer's Manual POSIX_OPENPT(3)NAME
posix_openpt - open a pseudo-terminal device
SYNOPSIS
#define _XOPEN_SOURCE
#include <stdlib.h>
#include <fcntl.h>
char *posix_openpt(int flags);
DESCRIPTION
The posix_openpt() function opens an unused pseudo-terminal master
device, returning a file descriptor that can be used to refer to that
device.
The flags argument is a bit mask that ORs together zero or more of the
following flags:
O_RDWR Open the device for both reading and writing. It is usual to
specify this flag.
O_NOCTTY
Do not make this device the controlling terminal for the
process.
RETURN VALUE
On success, ptsname() returns a non-negative file descriptor which is
the lowest numbered unused descriptor. On failure, -1 is returned, and
errno is set to indicate the error.
ERRORS
See open(2).
CONFORMING TOposix_openpt() is part of the Unix98 pseudo-terminal support (see
pts(4)). This function is specified in POSIX.1-2001.
NOTES
This function is a recent invention in POSIX. Some Unix implementa‐
tions that support System V (aka Unix 98) pseudo-terminals don't have
this function, but it is easy to implement:
int
posix_openpt(int flags)
{
return open("/dev/ptmx", flags);
}
SEE ALSOopen(2), getpt(3), grantpt(3), ptsname(3), unlock(3), pts(4), pty(7)PTY Control 2004-12-17 POSIX_OPENPT(3)