Create a temp file with a specific extension using php

Question

How do I create a temporary file with a specified extension in php. I came across tempnam() but using it the extension can't be specified.

Answer 1

Easiest way i have found is to create tempfile and then just rename it. For example:

 $tmpfname = tempnam(sys_get_temp_dir(), "Pre_");
 rename($tmpfname, $tmpfname .= '.pdf');

Answer 2

my way is using tempnam

$file = tempnam(sys_get_temp_dir(), 'prefix');
file_put_contents($file.'.extension', $data);
{
   //use your file
}
unlink($file);//to delete an empty file that tempnam creates
unlink($file.'.extension');//to delete your file

Answer 3

This might simulate mkstemp() (see http://linux.die.net/man/3/mkstemp ) a bit, achieving what you want to do:

function mkstemp( $template ) {
  $attempts = 238328; // 62 x 62 x 62
  $letters  = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  $length   = strlen($letters) - 1;

  if( mb_strlen($template) < 6 || !strstr($template, 'XXXXXX') )
    return FALSE;

  for( $count = 0; $count < $attempts; ++$count) {
    $random = "";

    for($p = 0; $p < 6; $p++) {
      $random .= $letters[mt_rand(0, $length)];
    }

    $randomFile = str_replace("XXXXXX", $random, $template);

    if( !($fd = @fopen($randomFile, "x+")) )
      continue;

    return $fd;
  }

  return FALSE;
}

So you could do:

if( ($f = mkstemp("test-XXXXXX.txt")) ) {
  fwrite($f, "test\n");
  fclose($f);
}

Answer 4

public static function makeTempFileInFolder($prefix, $suffix, $folder="")
{
  if (strlen($folder)==0) $folder = sys_get_temp_dir();
  do { 
    $file = $folder."/".$prefix.rand(1,99999).time().$suffix; 
  } while (file_exists($file));
  return $file;
}

Answer 5

Let's say tempnam() gives you a file of "filename". You move it to "filename.ext". At any point, tempnam() can give you "filename" again. If you check for "filename.ext", reject the filename given by tempnam(), and call it again, you still end up with the possibility that between one step and another, a file will get created with the same name. (This is discussed in the user comments on the documentation page for tempnam(): https://www.php.net/manual/en/function.tempnam.php. )

However, if you just leave the file created by tempnam() alone (not deleting "filename" until you delete "filename.ext") and work with that filename + the extension, then there is no chance that tempnam() will use that filename again (as far as I can see). Yes, it is messy to have "filename" and "filename.ext" for every single file. On the other hand, it solves the problem.

Answer 6

The same as tempnam() except the additional parameter:

function tempnamp($dir, $prefix, $postfix) {
  $maxAttempts = 1000;
  // Trim trailing slashes from $dir.
  $dir = rtrim($dir, DIRECTORY_SEPARATOR);
  // If we don't have permission to create a directory, fail, otherwise we will
  // be stuck in an endless loop.
  if (!is_dir($dir) || !is_writable($dir)) return false;
  // Make sure characters in prefix and postfix are safe.
  if (strpbrk($prefix, '\\/:*?"<>|') !== false) return false;
  if (strpbrk($postfix, '\\/:*?"<>|') !== false) return false;
  // Attempt to create a random file until it works.
  $attempts = 0;
  do
  {
    $path = $dir.DIRECTORY_SEPARATOR.$prefix.mt_rand(100000, mt_getrandmax()).$postfix;
    $fp = @fopen($path, 'x+');
  } while (!$fp && $attempts++ < $maxAttempts);
  if ($fp) fclose($fp);
  return $path;
}

That 'p' at the end of the name stands for 'postfix'.

Answer 7

Rename does it, find the extension with pathinfo and then replace with the extension you want.

$tmpfname = tempnam(sys_get_temp_dir(), 'FOO');
$newname = str_replace(pathinfo($tmpfname, PATHINFO_EXTENSION),'pdf',$tmpfname);
rename($tmpfname, $newname);
//do what you want with $newname
unlink($newname);

Answer 8

I prefer this solution:

$uid = uniqid('', true);
$path = sys_get_temp_dir() . "some_prefix_$uid.myextension";

Note: I do not put the prefix in uniqid because, IMHO, it's not its duty

Answer 9

Maybe using

move_uploaded_file($tmp_name, "$uploads_dir/$name.myextension");

See http://php.net/manual/en/function.move-uploaded-file.php#example-2209