[mixed$data = NULL]
eio_read reads up to length bytes from fd file descriptor at offset. The read bytes are stored in result argument of callback.
Stream, Socket resource, or numeric file descriptor
Maximum number of bytes to read.
Offset within the file.
The request priority: EIO_PRI_DEFAULT, EIO_PRI_MIN, EIO_PRI_MAX, or null. If null passed, pri internally is set to EIO_PRI_DEFAULT.
callback function is called when the request is done. It should match the following prototype:
void callback(mixed $data, int $result[, resource $req]);
is custom data passed to the request.
request-specific result value; basically, the value returned by corresponding system call.
is optional request resource which can be used with functions like eio_get_last_error
Arbitrary variable passed to callback.
eio_read stores read bytes in result argument of callback function.