# eio_open

(PECL eio >= 0.0.1dev)

eio_open — Opens a file

### 说明

eio_open ( string `$path` , int `$flags` , int `$mode` , int `$pri` , callable `$callback` [, mixed `$data` = NULL ] ) : resource

eio_open() opens file specified by `path` in access mode `mode` with

### 参数

`path`

  Path of the file to be opened.

  Warning

  In some SAPIs(e.g. PHP-FPM) it could fail, if you don't specify full path.

`flags`

  One of EIO_O_* constants, or their combinations. EIO_O_* constants have the same meaning, as their corresponding O_* counterparts defined in fnctl.h C header file. Default is `EIO_O_RDWR`.

`mode`

  One of EIO_S_I* constants, or their combination (via bitwise OR operator). The constants have the same meaning as their S_I* counterparts defined in » sys/stat.h C header file. Required, if a file is created. Otherwise ignored.

`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_open() returns file descriptor in `result` argument of `callback` on success; otherwise, `result` is equal to `-1`.

### 范例

Example #1 eio_open() example

    <?php
    $temp_filename = "eio-temp-file.tmp";

    /* Is called when eio_close() finishes */
    function my_close_cb($data, $result) {
     // Zero indicates success
        var_dump($result == 0);
     @unlink($data);
    }

    /* Is called when eio_open() finishes */
    function my_file_opened_callback($data, $result) {
     // $result should contain the file descriptor
        var_dump($result > 0);

        if ($result > 0) {
      // Close the file
            eio_close($result, EIO_PRI_DEFAULT, "my_close_cb", $data);
            eio_event_loop();
        }
    }

    // Create new file for reading and writing
    // Deny group and others to do anything with that file
    eio_open($temp_filename, EIO_O_CREAT | EIO_O_RDWR, EIO_S_IRUSR | EIO_S_IWUSR,
      EIO_PRI_DEFAULT, "my_file_opened_callback", $temp_filename);
    eio_event_loop();
    ?>

以上例程的输出类似于：

    bool(true)
    bool(true)

### 参见

- eio_mknod