Make a terminal device a controlling device
#include <termios.h> int tcsetsid( const int fildes, const pid_t pid );
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The tcsetsid() function makes the terminal device associated with the file descriptor argument fildes into a controlling terminal that's associated with the process pid. If successful, this call causes subsequent hangup conditions on the terminal device fildes to generate a SIGHUP signal on the given process.
This call is equivalent to calling ioctl( fildes, TIOCSCTTY ) to set the controlling terminal to the current process. You can clear the controlling terminal by passing -1 as fildes.