This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function at your own risk.
Places the terminal in raw mode. Raw mode is similar to cbreak mode, in that characters typed are immediately passed through to the user program. The differences that are that in raw mode, the interrupt, quit, suspend and flow control characters are all passed through uninterpreted, instead of generating a signal.