.\" Copyright (c) 1991, 1993
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.\"	@(#)tcgetpgrp.3	8.1 (Berkeley) 6/4/93
.\" %FreeBSD: src/lib/libc/gen/tcgetpgrp.3,v 1.6.2.2 2001/12/14 18:33:51 ru Exp %
.\"
.\" $FreeBSD$
.Dd June 4, 1993
.Dt TCGETPGRP 3
.Os
.Sh 名称
.Nm tcgetpgrp
.Nd フォアグラウンドの処理グループIDを取得
.Sh ライブラリ
.Lb libc
.Sh 書式
.In sys/types.h
.In unistd.h
.Ft pid_t
.Fn tcgetpgrp "int fd"
.Sh 解説
.Fn tcgetpgrp
関数は、端末デバイスで行っているフォアグラウンドの処理
グループの処理グループ
ID
を返します。フォアグラウンドの処理グループがない場合、
.Fn tcgetpgrp
は無効なプロセス
ID
を返します。
.Sh エラー
エラーが起きた場合、
.Fn tcgetpgrp
は
-1 を返し、エラーを示すために
次のようにグローバル変数
.Va errno
が設定されます：
.Bl -tag -width Er
.It Bq Er EBADF
引数
.Fa fd
が有効なファイル記述子ではありません。
.It Bq Er ENOTTY
呼び出し側処理が制御端末を持っていないか、または
.Fa fd
で表わされている端末デバイスが制御端末ではありません。
.El
.Sh 関連項目
.Xr setpgid 2 ,
.Xr setsid 2 ,
.Xr tcsetpgrp 3
.Sh 規格
.Fn tcgetpgrp
関数は、
.St -p1003.1-88
規格に適合しているものと考えられます。