foreground process group ID
If the process has a controlling terminal, the
() function sets the foreground process
group ID associated with the terminal device to
. The terminal device associated with
must be the controlling terminal of the
calling process and the controlling terminal must be currently associated with
the session of the calling process. The value of
must be the same as the process group
ID of a process in the same session as the calling process.
If the calling process is a member of a background process group, the process
group will be sent a
signal. If the
calling process is blocking or ignoring
signals, the process is allowed to
perform the operation and the
signal is not sent.
Upon successful completion, tcsetpgrp
() returns a
value of zero.
If an error occurs, tcsetpgrp
() returns -1 and the
global variable errno
is set to indicate the
error, as follows:
- The fd argument is not a
valid file descriptor.
- The tcsetpgrp() function was
interrupted by a signal.
- An invalid value of
pgrp_id was specified.
- The calling process does not have a controlling terminal,
or the file represented by fd is not the
controlling terminal, or the controlling terminal is no longer associated
with the session of the calling process.
- The pgrp_id argument does
not match the process group ID of a process in the same session as the
() function is expected to be
compliant with the IEEE Std 1003.1-1988