eio_read
PHP function
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(PECL eio >= 0.0.1dev)
Read from a file descriptor at given offset
Description
eio_read(mixed $fd, int $length, int $offset, int $pri, callable $callback, mixed $data = NULL): resource
eio_read() reads up to length bytes from fd file descriptor at offset. The read bytes are stored in result argument of callback.
Parameters
fdStream, Socket resource, or numeric file descriptor
lengthMaximum number of bytes to read.
offsetOffset within the file.
priValues
callbackProto
dataArbitrary variable passed to
callback.
Return Values
eio_read() stores read bytes in result argument of callback function.
Examples
eio_read() example
php
<?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:
output
string(5) "34567"