eio_ftruncate

(PECL eio >= 0.0.1dev)

eio_ftruncate — Truncate a file

说明

eio_ftruncate(
    mixed $fd,
    int $offset = 0,
    int $pri = EIO_PRI_DEFAULT,
    callable $callback = NULL,
    mixed $data = NULL
): resource

eio_ftruncate() causes a regular file referenced by fd file descriptor to be truncated to precisely length bytes.

参数

fd

Stream, Socket resource, or numeric file descriptor.

offset

Offset from beginning of the file

pri

请求的优先级：EIO_PRI_DEFAULT，EIO_PRI_MIN，EIO_PRI_MAX 或 null。如果是 null，pri 将设为 EIO_PRI_DEFAULT。

callback

callback 函数在请求完成时被调用。其应匹配一下原型：

void callback(mixed $data, int $result[, resource $req]);

data: 传递给请求的用户数据。
result: 针对请求的结果的值。通常是相应的系统调用返回的值。
req: 可选的请求资源，可被 eio_get_last_error() 之类的函数使用。

data

Arbitrary variable passed to callback.

返回值

eio_ftruncate() returns request resource on success, 或者在失败时返回 false.

参见

eio_truncate() - Truncate a file

＋add a note

User Contributed Notes

There are no user contributed notes for this page.