.\" Copyright (C) 2002 Andries Brouwer <aeb@cwi.nl>

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.TH TCGETSID 3 2015-08-08 "GNU" "Linux Programmer's Manual"

.SH NAME

tcgetsid \- get session ID

.SH SYNOPSIS

.BR "#define _XOPEN_SOURCE 500" "        /* See feature_test_macros(7) */"

.br

.B "#include <termios.h>"

.PP

.BI "pid_t tcgetsid(int " fd );

.SH DESCRIPTION

The function

.BR tcgetsid ()

returns the session ID of the current session that has the

terminal associated to

.I fd

as controlling terminal.

This terminal must be the controlling terminal of the calling process.

.SH RETURN VALUE

When

.I fd

refers to the controlling terminal of our session,

the function

.BR tcgetsid ()

will return the session ID of this session.

Otherwise, \-1 is returned, and

.I errno

is set appropriately.

.SH ERRORS

.TP

.B EBADF

.I fd

is not a valid file descriptor.

.TP

.B ENOTTY

The calling process does not have a controlling terminal, or

it has one but it is not described by

.IR fd .

.SH VERSIONS

.BR tcgetsid ()

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 tcgetsid ()

T}	Thread safety	MT-Safe

.TE

.SH CONFORMING TO

POSIX.1-2001, POSIX.1-2008.

.SH NOTES

This function is implemented via the

.B TIOCGSID

.BR ioctl (2),

present

since Linux 2.1.71.

.SH SEE ALSO

.BR getsid (2)

.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/.