(PECL eio >= 0.0.1dev)
eio_open — Opens a file
$path,$flags,$mode,$pri,$callback,$data = NULL
  eio_open() opens file specified by
  path in access mode mode with
  
pathPath of the file to be opened.
In some SAPIs(e.g. PHP-FPM) it could fail, if you don't specify full path.
flagsOne 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.
    
modeOne 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.
     
   eio_open() returns file descriptor in
   result argument of callback
   on success; otherwise, result is equal to -1.
  
示例 #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();
?>以上示例的输出类似于:
bool(true) bool(true)
