set foreground process group
If the process has a controlling terminal, the
function sets the foreground process group ID associated with the terminal
device to pgrp_id. The terminal device associated with
fd 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 pgrp_id
must be the same as the process group ID of a process in the same session as
the calling process.
Upon successful completion,
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.
- 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 calling process.
setpgid(2), setsid(2), tcgetpgrp(3)
tcsetpgrp() function is expected to be
compliant with the IEEE Std 1003.1-1988