.\" This man page was written by Jeremy Phelps <jphelps@notreached.net>.

.\"

.\" %%%LICENSE_START(FREELY_REDISTRIBUTABLE)

.\" Redistribute and modify at will.

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.TH GETPT 3 2015-03-02 "GNU" "Linux Programmer's Manual"

.SH NAME

getpt \- open the pseudoterminal master (PTM)

.SH SYNOPSIS

.nf

.BR "#define _GNU_SOURCE" "             /* See feature_test_macros(7) */"

.B #include <stdlib.h>

.PP

.B "int getpt(void);"

.fi

.SH DESCRIPTION

.BR getpt ()

opens a pseudoterminal master and returns its file descriptor.

It is equivalent to

.PP

.in +4n

.EX

open(/dev/ptmx, O_RDWR | O_NOCTTY);

.EE

.in

.PP

on Linux systems, though the pseudoterminal master is located

elsewhere on some systems that use GNU Libc.

.SH RETURN VALUE

.BR getpt ()

returns an open file descriptor upon successful completion.

Otherwise, it

returns \-1 and sets

.I errno

to indicate the error.

.SH ERRORS

.BR getpt ()

can fail with various errors described in

.BR open (2).

.SH VERSIONS

.BR getpt ()

is provided in glibc since version 2.1.

.SH ATTRIBUTES

For an explanation of the terms used in this section, see

.BR attributes (7).

.TS

allbox;

lb lb lb

l l l.

Interface	Attribute	Value

T{

.BR getpt ()

T}	Thread safety	MT-Safe

.TE

.SH CONFORMING TO

.BR getpt ()

is glibc-specific;

use

.BR posix_openpt (3)

instead.

.SH SEE ALSO

.BR grantpt (3),

.BR posix_openpt (3),

.BR ptsname (3),

.BR unlockpt (3),

.BR ptmx (4),

.BR pty (7)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I man-pages

project.

A description of the project,

information about reporting bugs,

and the latest version of this page,

can be found at

\%https://www.kernel.org/doc/man\-pages/.