The
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,
tcgetpgrp ();
returns an invalid process ID.
ERRORS
If an error occurs,
tcgetpgrp ();
returns -1 and the global variable
errno
is set to indicate the error, as follows:
Bq Er EBADF
The
Fa fd
argument is not a valid file descriptor.
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.