Read from the file. read() inherits from the Stream utility class.
file.read()
file.read(buf, len)
file
: an instance of the File class (returned by SD.open()).buf
: an array of characters or bytes.len
: the number of elements in buf.When used as file.read()
:
The next byte (or character), or -1 if none is available.
When used as file.read(buf, len)
:
The amount of bytes read, or -1 if an error occurred.