io.read(<file object> , <length>)
The io.read() function is used to read data from the file on SD card.
Notice: other read commands (like "all", etc..) are *not supported.
file objecta file object that was returned by the io.open() function. The file must be opened in read mode.
lengthnumber of characters/bytes to read. The number of actual read/returned characters can be less if the file end is reached.
<string>a string with a length equal or less than
""a zero length string if the end of file was reached