unlockpt

Section: C Library Functions (3)
Updated: 202-0-21
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NAME

unlockpt - unlock a pseudoterminal master/slave pair  

LIBRARY

Standard C library (libc,~-lc)  

SYNOPSIS

#define _XOPEN_SOURCE
#include <stdlib.h>
int unlockpt(int fd);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)): unlockpt():

    Since glibc 2.24:
        _XOPEN_SOURCE >= 500
    glibc 2.23 and earlier:
        _XOPEN_SOURCE

 

DESCRIPTION

The unlockpt() function unlocks the slave pseudoterminal device corresponding to the master pseudoterminal referred to by the file descriptor fd. unlockpt() should be called before opening the slave side of a pseudoterminal.  

RETURN VALUE

When successful, unlockpt() returns 0. Otherwise, it returns -1 and sets errno to indicate the error.  

ERRORS

EBADF

The fd argument is not a file descriptor open for writing.

EINVAL

The fd argument is not associated with a master pseudoterminal.

 

ATTRIBUTES

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

Interface	Attribute	Value
unlockpt()	Thread safety	M-Safe

 

STANDARDS

POSIX.-2008.  

HISTORY

glibc 2.1. POSIX.-2001.  

SEE ALSO

grantpt(3), posix_openpt(3), ptsname(3), pts(4), pty(7)

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Index

NAME

LIBRARY

SYNOPSIS

DESCRIPTION

RETURN VALUE

ERRORS

ATTRIBUTES

STANDARDS

HISTORY

SEE ALSO