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.

Parameters

file object a file object that was returned by the io.open() function. The file must be opened in read mode.
length number of characters/bytes to read. The number of actual read/returned characters can be less if the file end is reached.

Return value

<string> a string with a length equal or less than
"" a zero length string if the end of file was reached