int tcsetpgrp(int fildes, pid_t pgid_id);
IEEE Std 1003.1-2017
tcsetpgrp() - set the foreground process group ID
If the process has a controlling terminal,
tcsetpgrp() shall set the foreground process group ID associated with the terminal to pgid_id. The application shall ensure that the file associated with fildes is the controlling terminal of the calling process and the controlling terminal is currently associated with the session of the calling process. The application shall ensure that the value of pgid_id matches a process group ID of a process in the same session as the calling process.
Attempts to use
tcsetpgrp() from a process which is a member of a background process group on a fildes associated with its controlling terminal shall cause the process group to be sent a
SIGTTOU signal. If the calling thread is blocking
SIGTTOU signals or the process is ignoring
SIGTTOU signals, the process shall be allowed to perform the operation, and no signal is sent.
Upon successful completion,
0 shall be returned. Otherwise,
-1 shall be returned and
errno set to indicate the error.
tcsetpgrp() function shall fail if:
EBADF- The fildes argument is not a valid file descriptor.
EINVAL- This implementation does not support the value in the pgid_id argument.
EIO- The process group of the writing process is orphaned, the calling thread is not blocking
SIGTTOU, and the process is not ignoring SIGTTOU.
ENOTTY- The calling process does not have a controlling terminal, or the file is not the controlling terminal, or the controlling terminal is no longer associated with the session of the calling process.
EPERM- The value of pgid_id is a value supported by the implementation, but does not match the process group ID of a process in the same session as the calling process.