(PECL eio >= 0.0.1dev)
eio_read — Read from a file descriptor at given offset.
eio_read() reads up to length bytes from fd file descriptor at offset. The read bytes are stored in result argument of callback.
The 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($data, $result);
Arbitrary variable passed to callback.
eio_read() stores read bytes in result argument of callback function.
Example #1 eio_read() example
<?php
// Open a temporary file and write some bytes there
$temp_filename = "eio-temp-file.tmp";
$fp = fopen($temp_filename, "w");
fwrite($fp, "1234567890");
fclose($fp);
/* Is called when eio_read() is done */
function my_read_cb($data, $result) {
global $temp_filename;
// Output read bytes
var_dump($result);
// Close file
eio_close($data);
eio_event_loop();
// Remove temporary file
@unlink($temp_filename);
}
/* Is called when eio_open() is done */
function my_file_opened_callback($data, $result) {
// $result should contain the file descriptor
if ($result > 0) {
// Read 5 bytes starting from third
eio_read($result, 5, 2, EIO_PRI_DEFAULT, "my_read_cb", $result);
eio_event_loop();
} else {
// eio_open() failed
unlink($data);
}
}
// Open the file for reading and writing
eio_open($temp_filename, EIO_O_RDWR, NULL,
EIO_PRI_DEFAULT, "my_file_opened_callback", $temp_filename);
eio_event_loop();
?>
The above example will output something similar to:
string(5) "34567"