The LEDs are set to correspond to the lower three bits of argp . Since 1.1.54 the leds can be made to display arbitrary information, but by default they display the keyboard flags. The following two ioctl's are used to access the keyboard flags. The lower 16 bits of argp specify the period in clock cycles, and the upper 16 bits give the duration in msec. If the duration is zero, the sound is turned off.
Control returns immediately.
In either case, control returns immediately. Gets screen font in expanded form. Sets screen font. Get screen mapping from kernel. The calling process indicates its willingness to accept the signal argp when it is generated by pressing an appropriate key combination.