Wait for a character to arrive at a filehandle. The filehandle can be either a console handle, or a regular file. For a regular file most filesystems will return a character immediately, but sometimes (for example a network handler) the character may not have arrived.
INPUTS
file
File to wait for a character on.
timeout
Number of microseconds to wait for the character to arrive. A value of 0 says to wait indefinately.
RESULT
!= 0 if a character arrived before the timeout expired == 0 if no character arrived