• 首页
  • vue
  • TypeScript
  • JavaScript
  • scss
  • css3
  • html5
  • php
  • MySQL
  • redis
  • jQuery
  • tmpfile()

    (PHP 4, PHP 5, PHP 7)

    建立一个临时文件

    说明

    tmpfile(void): resource

    以读写(w+)模式建立一个具有唯一文件名的临时文件,返回一个文件句柄。

    文件会在关闭后(用fclose())自动被删除,或当脚本结束后。

    详细信息请参考系统手册中的tmpfile(3)函数,以及stdio.h头文件。

    返回值

    返回一个与fopen()所打开返回类似的新文件句柄,或者在失败时返回FALSE.

    范例

    Example #1tmpfile()例子

    <?php
    $temp = tmpfile();
    fwrite($temp, "writing to tempfile");
    fseek($temp, 0);
    echo fread($temp, 1024);
    fclose($temp); // this removes the file
    ?>
    

    以上例程会输出:

    writing to tempfile
    

    参见

    To get the underlying file path of a tmpfile file pointer:
    <?php
    $file = tmpfile();
    $path = stream_get_meta_data($file)['uri']; // eg: /tmp/phpFx0513a
    I found this function useful when uploading a file through FTP. One of the files I was uploading was input from a textarea on the previous page, so really there was no "file" to upload, this solved the problem nicely:
    <?php
      # Upload setup.inc
      $fSetup = tmpfile();
      fwrite($fSetup,$setup);
      fseek($fSetup,0);
      if (!ftp_fput($ftp,"inc/setup.inc",$fSetup,FTP_ASCII)) {
        echo "<br /><i>Setup file NOT inserted</i><br /><br />";
      }
      fclose($fSetup);
    ?>
    The $setup variable is the contents of the textarea.
    And I'm not sure if you need the fseek($temp,0); in there either, just leave it unless you know it doesn't effect it.
    Since this function may not be working in some environments, here is a simple workaround:
    function temporaryFile($name, $content)
    {
      $file = DIRECTORY_SEPARATOR .
          trim(sys_get_temp_dir(), DIRECTORY_SEPARATOR) .
          DIRECTORY_SEPARATOR .
          ltrim($name, DIRECTORY_SEPARATOR);
      file_put_contents($file, $content);
      register_shutdown_function(function() use($file) {
        unlink($file);
      });
      return $file;
    }
    No, the fseek() is necessary - after writing to the file, the file pointer (I'll use "file pointer" to refer to the current position in the file, the thing you change with fseek()) is at the end of the file, and reading at the end of the file gives you EOF right away, which manifests itself as an empty upload.
    Where you might be getting confused is in some systems' requirement that one seek or flush between reading and writing the same file. fflush() satisfies that prerequisite, but it doesn't do anything about the file pointer, and in this case the file pointer needs moving.
    -- Josh
    To get tmpfile contents:
    <?php
     $tmpfile = tmpfile();
     $tmpfile_path = stream_get_meta_data($tmpfile)['uri'];
     // ... write to tmpfile ...
     $tmpfile_content = file_get_contents($tmpfile_path);
    ?>
    Perhaps not the best way for production code, but good enough for logging or a quick var_dump() debug run.
    Beware that PHP's tmpfile is not an equivalent of unix' tmpfile.
    PHP (at least v. 5.3.17/linux I'm using now) creates a file in /tmp with prefix "php", and deletes that file on fclose or script termination.
    So, if you want to be sure that you don't leave garbage even in case of a fatal error, or killed process, you shouldn't rely on this function.
    Use the classical method of deleting the file after creation:
    <?php
    $fn = tempnam ('/tmp', 'some-prefix-');
    if ($fn)
     {
      $f = fopen ($fn, 'w+');
      unlink ($fn); // even if fopen failed, because tempnam created the file
      if ($f)
       {
        do_something_with_file_handle ($f);
       }
     }
    ?>
    

    上篇:tempnam()

    下篇:touch()