ProcessGroupID
getTerminalProcessGroupID fd calls tcgetpgrp to obtain the ProcessGroupID of the foreground process group associated with the terminal attached to Fd fd.
setProcessGroupID pid pgid calls setpgid to set the ProcessGroupID for process pid to pgid. This function is currently deprecated, and might be changed to setting the ProcessGroupID for the current process in future versions.
setProcessGroupIDOf pid pgid calls setpgid to set the ProcessGroupIDOf for process pid to pgid.
setTerminalProcessGroupID fd pgid calls tcsetpgrp to set the ProcessGroupID of the foreground process group associated with the terminal attached to Fd fd to pgid.