posix_openpt(2) open a pseudo-terminal device

LIBRARY

Lb libc

SYNOPSIS

In stdlib.h In fcntl.h Ft int Fn posix_openpt int oflag

DESCRIPTION

The Fn posix_openpt function allocates a new pseudo-terminal and establishes a connection with its master device. A slave device shall be created in /dev/pts After the pseudo-terminal has been allocated, the slave device should have the proper permissions before it can be used (see grantpt(3)). The name of the slave device can be determined by calling ptsname(3).

The file status flags and file access modes of the open file description shall be set according to the value of Fa oflag . Values for Fa oflag are constructed by a bitwise-inclusive OR of flags from the following list, defined in In fcntl.h :

O_RDWR
Open for reading and writing.
O_NOCTTY
If set Fn posix_openpt shall not cause the terminal device to become the controlling terminal for the process.
O_CLOEXEC
Set the close-on-exec flag for the new file descriptor.

The Fn posix_openpt function shall fail when Fa oflag contains other values.

RETURN VALUES

Upon successful completion, the Fn posix_openpt function shall allocate a new pseudo-terminal device and return a non-negative integer representing a file descriptor, which is connected to its master device. Otherwise, -1 shall be returned and errno set to indicate the error.

ERRORS

The Fn posix_openpt function shall fail if:

Bq Er ENFILE
The system file table is full.
Bq Er EINVAL
The value of Fa oflag is not valid.
Bq Er EAGAIN
Out of pseudo-terminal resources.

STANDARDS

The Fn posix_openpt function conforms to St -p1003.1-2001 . The ability to use O_CLOEXEC is an extension to the standard.

HISTORY

The Fn posix_openpt function appeared in Fx 5.0 . In Fx 8.0 , this function was changed to a system call.

NOTES

The flag O_NOCTTY is included for compatibility; in Fx , opening a terminal does not cause it to become a process's controlling terminal.

AUTHORS

An Ed Schouten Aq [email protected]