The Eof function determines if the end of the specified file has been reached.
Used in loop constructions to detect the end of the file which is processed.
<filename>, string, name of the file.
var, integer. If the end of the file has been reached, the return value is 1, otherwise 0. If <filename> is not open for reading or does not exist, the return value is 0.
'If the file does not exist