Transfer data between file descriptors

说明

eio_sendfile(
    mixed $out_fd,
    mixed $in_fd,
    int $offset,
    int $length,
    int $pri = ?,
    callable $callback = ?,
    string $data = ?
): resource

eio_sendfile() copies data between one file descriptor and another. See SENDFILE(2) man page for details.

参数

out_fd

Output stream, Socket resource, or file descriptor. Should be opened for writing.

in_fd

Input stream, Socket resource, or file descriptor. Should be opened for reading.

offset

Offset within the source file.

length

Number of bytes to copy.

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