xref: /freebsd/lib/libc/gen/tcgetsid.3 (revision a0b9e2e854027e6ff61fb075a1309dbc71c42b54)
1.\" Copyright (c) 2008 David Xu <davidxu@FreeBSD.org>
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25.\" $FreeBSD$
26.\"
27.Dd April 15, 2008
28.Dt TCGETSID 3
29.Os
30.Sh NAME
31.Nm tcgetsid
32.Nd get session ID associated with a controlling terminal
33.Sh LIBRARY
34.Lb libc
35.Sh SYNOPSIS
36.In sys/types.h
37.In termios.h
38.Ft pid_t
39.Fn tcgetsid "int fd"
40.Sh DESCRIPTION
41The
42.Fn tcgetsid
43function returns the process group ID of the session leader for a
44controlling terminal specified by
45.Fa fd .
46.Sh ERRORS
47If an error occurs,
48.Fn tcgetsid
49returns -1 and the global variable
50.Va errno
51is set to indicate the error, as follows:
52.Bl -tag -width Er
53.It Bq Er EBADF
54The
55.Fa fd
56argument is not a valid file descriptor.
57.It Bq Er ENOTTY
58The calling process does not have a controlling terminal or the
59underlying terminal device represented by
60.Fa fd
61is not the controlling terminal.
62.El
63.Sh SEE ALSO
64.Xr getsid 2 ,
65.Xr setsid 2 ,
66.Xr tcgetpgrp 3 ,
67.Xr tcsetsid 3
68.Sh STANDARDS
69The
70.Fn tcgetsid
71function conforms to
72.St -xpg4.2 .
73