tmpfile

(PHP 4, PHP 5, PHP 7)

tmpfile — Creates a temporary file

Description

resource tmpfile ( void )

Creates a temporary file with a unique name in read-write (w+) mode and returns a file handle .

The file is automatically removed when closed (for example, by calling fclose(), or when there are no remaining references to the file handle returned by tmpfile()), or when the script ends.

For details, consult your system documentation on the tmpfile(3) function, as well as the stdio.h header file.

Return Values

Returns a file handle, similar to the one returned by fopen(), for the new file or FALSE on failure.

Examples

Example #1 tmpfile() example


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

The above example will output:

writing to tempfile

User Contributed Notes

chris [at] pureformsolutions [dot] com

10 years ago


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.

oremanj at gmail dot com

9 years ago


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

ssandor

3 years ago


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);
      }
  }
?>

David dot Crowe at cnp-wireless dot com

1 year ago


The phrase, "when the script ends" is not clear. Does this mean when the session ends (assuming the file is never explicitly closed)?

Anonymous