當(dāng)進(jìn)程的控制終端關(guān)閉時，發(fā)送給進(jìn)程 SIGHUP 信號。
On POSIX-compliant platforms, SIGHUP is a signal sent to a process when its controlling terminal is closed. (It was originally designed to notify the process of a serial line drop). SIGHUP is a symbolic constant defined in theheader file signal.h.