eio_seek
(PECL eio >= 0.5.0b)
eio_seek — Repositions the offset of the open file associated with the fd
argument to the argument offset
according to the directive whence
說明
mixed
$fd
,int
$offset
,int
$whence
,int
$pri
= EIO_PRI_DEFAULT,callable
$callback
= NULL,mixed
$data
= NULL): resource
eio_seek() repositions the offset of the open file associated with
stream, Socket resource, or file descriptor specified by fd
to the argument offset
according to the directive whence
as follows:
EIO_SEEK_SET
- Set position equal tooffset
bytes.EIO_SEEK_CUR
- Set position to current location plusoffset
.EIO_SEEK_END
- Set position to end-of-file plusoffset
.
參數
-
fd
-
Stream, Socket resource, or numeric file descriptor
-
offset
-
Starting point from which data is to be read.
-
length
-
Number of bytes to be read.
-
pri
-
請求的優先順序:
EIO_PRI_DEFAULT
,EIO_PRI_MIN
,EIO_PRI_MAX
或null
。如果是null
,pri
將設為EIO_PRI_DEFAULT
。 -
callback
-
callback
函式在請求完成時被呼叫。其應匹配一下原型:void callback(mixed $data, int $result[, resource $req]);
-
data
-
傳遞給請求的用戶數據。
-
result
-
針對請求的結果的值。通常是相應的系統呼叫返回的值。
-
req
-
可選的請求資源,可被 eio_get_last_error() 之類的函式使用。
-
-
data
-
Arbitrary variable passed to
callback
.
返回值
eio_seek() returns request resource on success, 或者在失敗時返回 false
.