tcsetpgrp - set foreground process group ID

Syntax	#include <unistd.h> Optional #include <sys/types.h> (End) int tcsetpgrp(int fildes, pid_t pgid_id);
Description	If the process has a controlling terminal, tcsetpgrp() will set the foreground process group ID associated with the terminal to the value pgid_id. The file of the terminal specified by fildes 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 pgid_id must match a process group ID of a process in the same session as the calling process.
Return val.	0 -1	if successful. if an error occurs. errno is set to indicate the error.
Errors	tcsetpgrp() will fail if:
	EBADF	fildes is not a valid file descriptor.
	EINVAL	pgid_id is not a valid process group ID.
	Extension
	EINVAL	An attempt was made to access a BS2000 file. (End)
	ENOTTY	The calling process does not have a controlling terminal, or the controlling terminal is no longer associated with the session of the calling process.
	EPERM	The value of pgid_id does not match the process group ID of a process in the same session as the calling process.
See also	tcgetpgrp(), sys/types.h, unistd.h.