(PECL eio >= 0.0.1dev)
eio_truncate — Truncate a file
$path
[, int $offset = 0
[, int $pri = EIO_PRI_DEFAULT
[, callable $callback = NULL
[, mixed $data = NULL
]]]] )
eio_truncate() causes the regular file named by path to be truncated to
a size of precisely length bytes
path
File path
offset
Offset from beginning of the file.
pri
请求的优先级: EIO_PRI_DEFAULT, EIO_PRI_MIN, EIO_PRI_MAX, or NULL.
如果是 NULL , pri 将设为
EIO_PRI_DEFAULT.
callback
callback 函数将在请求结束时被调用.
必须符合此原型:
void callback($data, $result);
$data 是传给该请求的特定数据.
$result 包含特定请求的结果值, 通常是相应的系统调用的返回值.
data
Arbitrary variable passed to callback.
eio_busy() returns request resource on success or FALSE on error.