HID command_blink_on prevent beep

[bcoles]

You may be pleased to note that a value of -1 will prevent the device from beeping. This comes at the cost of one additional byte, thus decreasing the available space for the specified shell command by one byte.

A value of 1 will cause the device to beep for one second.
A value of 0 will cause the device to been infinitely.
ASCII values such as A will also cause the device to been infinitely.
A value of -1 will cause the blink executable to throw an error and exit, however the subsequent shell commands encompassed in backticks will still be executed by the system shell.

# ./blink -1
WARNING: blink: duration (-1) not in range 1-65535.
Usage: blink [<secs>]