posix_openpt()

Open a pseudo-terminal device

Synopsis:

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

int posix_openpt( int oflag );

Arguments:

oflag

Flags that specify the file status flags and file access modes of the open file description; a combination of the following:

O_RDWR — open for reading and writing.
O_NOCTTY — don't make the terminal device become the controlling terminal for the process.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The posix_openpt() function establishes a connection between a master device for a pseudo-terminal and a file descriptor. The file descriptor is used by other I/O functions that refer to that pseudo-terminal.

Returns:

A file descriptor for the master pseudo-terminal, or -1 if an error occurred (errno is set).

Errors:

EMFILE: All file descriptors available to the process are currently open.
ENFILE: The maximum allowable number of files is currently open in the system.
EINVAL: The value of oflag isn't valid.
EAGAIN: Out of pseudo-terminal resources.

Classification:

POSIX 1003.1 XSI

Safety:
Cancellation point	Yes
Interrupt handler	No
Signal handler	Yes
Thread	Yes