eio_read
(PECL eio >= 0.0.1dev)
eio_read — Read from a file descriptor at given offset.
Description
$fd
, int $length
, int $offset
, int $pri
, callable $callback
[, 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
.
Parameters
-
fd
-
Stream, Socket resource, or numeric file descriptor
-
length
-
Maximum number of bytes to read.
-
offset
-
Offset within the file.
-
pri
-
The request priority:
EIO_PRI_DEFAULT
,EIO_PRI_MIN
,EIO_PRI_MAX
, orNULL
. IfNULL
passed,pri
internally is set toEIO_PRI_DEFAULT
. -
callback
-
callback
function is called when the request is done. It should match the following prototype:void callback(mixed $data, int $result[, resource $req]);
-
data
-
is custom data passed to the request.
-
result
-
request-specific result value; basically, the value returned by corresponding system call.
-
req
-
is optional request resource which can be used with functions like eio_get_last_error()
-
-
data
-
Arbitrary variable passed to
callback
.
Return Values
eio_read() stores read bytes in
result
argument of callback
function.
Examples
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"
See Also
- eio_open
- eio_write
- eio_close
- eio_event_loop
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Расширения для управления процессами программ
- Eio
- eio_busy
- eio_cancel
- eio_chmod
- eio_chown
- eio_close
- eio_custom
- eio_dup2
- eio_event_loop
- eio_fallocate
- eio_fchmod
- eio_fchown
- eio_fdatasync
- eio_fstat
- eio_fstatvfs
- eio_fsync
- eio_ftruncate
- eio_futime
- eio_get_event_stream
- eio_get_last_error
- eio_grp_add
- eio_grp_cancel
- eio_grp_limit
- eio_grp
- eio_init
- eio_link
- eio_lstat
- eio_mkdir
- eio_mknod
- eio_nop
- eio_npending
- eio_nready
- eio_nreqs
- eio_nthreads
- eio_open
- eio_poll
- eio_read
- eio_readahead
- eio_readdir
- eio_readlink
- eio_realpath
- eio_rename
- eio_rmdir
- eio_seek
- eio_sendfile
- eio_set_max_idle
- eio_set_max_parallel
- eio_set_max_poll_reqs
- eio_set_max_poll_time
- eio_set_min_parallel
- eio_stat
- eio_statvfs
- eio_symlink
- eio_sync_file_range
- eio_sync
- eio_syncfs
- eio_truncate
- eio_unlink
- eio_utime
- eio_write
Коментарии
404 Not Found