getpt - Man Page

open a new pseudoterminal master


#define _GNU_SOURCE             /* See feature_test_macros(7) */
#include <stdlib.h>

int getpt(void);


getpt() opens a new pseudoterminal device and returns a file descriptor that refers to that device. It is equivalent to opening the pseudoterminal multiplexor device

open("/dev/ptmx", O_RDWR);

on Linux systems, though the pseudoterminal multiplexor device is located elsewhere on some systems that use the GNU C library.

Return Value

getpt() returns an open file descriptor upon successful completion. Otherwise, it returns -1 and sets errno to indicate the error.


getpt() can fail with various errors described in open(2).


getpt() is provided in glibc since version 2.1.


For an explanation of the terms used in this section, see attributes(7).

getpt()Thread safetyMT-Safe

Conforming to

getpt() is glibc-specific; use posix_openpt(3) instead.

See Also

grantpt(3), posix_openpt(3), ptsname(3), unlockpt(3), ptmx(4), pty(7)


This page is part of release 5.13 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at

Referenced By

posix_openpt(3), pts(4).

2021-03-22 GNU Linux Programmer's Manual