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.Dd "March 29, 1992"
.Dt TCGETPGRP 3
.Os
.Sh NAME
.Nm tcgetpgrp
.Nd get foreground process group ID
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <unistd.h>
.Ft pid_t
.Fn tcgetpgrp "int fd"
.Sh DESCRIPTION
The
.Nm tcgetpgrp
function returns the value of the process group ID of the foreground
process group associated with the terminal device.
If there is no foreground process group,
.Nm tcgetpgrp
returns an invalid process ID.
.Sh ERRORS
If an error occurs,
.Nm tcgetpgrp
returns -1 and the global variable
.Va errno
is set to indicate the error, as follows:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid file descriptor.
.It Bq Er ENOTTY
The calling process does not have a controlling terminal or the
underlying terminal device represented by
.Fa fd
is not the controlling terminal.
.El
.Sh SEE ALSO
.Xr setpgid 3 ,
.Xr setsid 2 ,
.Xr tcsetpgrp 3
.Sh STANDARDS
The
.Nm tcgetpgrp
function is expected to be compliant with the
.St -p1003.1-88
specification.