PHP Filesystem tempnam() Function

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The PHP Filesystem tempnam() function is used to create a temporary file with a unique filename in the specified directory, and it can return new temporary filename (with path), or false on failure.

This function can create a file with a unique filename, with access permission set to 0600 in the specified directory. If a directory does not exist or not writable, the tempnam() function is able to generate a file in the system's temporary directory and return the full path to that file includes its name.

Syntax

Below is the syntax of the PHP Filesystem tempnam() function −

string tempnam ( string $dir, string $prefix )

Parameters

Below are the required and optional parameters of the tempnam() function −

Return Value

The function tempnam() returns new temporary filename with path on success, and FALSE on failure.

PHP Version

The tempnam() function was first introduced as part of core PHP 4 and work well with the PHP 5, PHP 7 and PHP 8.

Example

Here is the simple example to see how the PHP Filesystem tempnam() function is used to create a temporary file in the given directory.

<?php
   echo tempnam("C:\PhpProject", "TEMP0");
?>

Output

Here is the outcome of the following code −

C:\PhpProject\TMPABFA.tmp

Example

Here is one more example to show the usage of tempnam() function to create a temporary file inside the given directory.

<?php
   // Path to the directory
   $dir = "C:\PhpProject"; 
   $prefix = "TEMPORARY";
   $tempfilename = tempnam($dir, $prefix); 
   
   $handle = fopen($tempfilename, "w"); 
   
   fwrite($handle, "writing to tempfile"); 
   fclose($handle); 

   echo "Temporary file has been created successfully! :" . $tempfilename;
?> 

Output

This will produce the following result −

Temporary file has been created successfully! : C:\PhpProject\TEMPORARYLgNr9K.tmp

Example

Here the PHP code which is used to create a temporary file using tempnam() function in the system's default temporary directory with a name which starts with "prefix_".

<?php
   $temp_file = tempnam(sys_get_temp_dir(), 'prefix_');
   if ($temp_file) {
      echo "Temporary file created: " . $temp_file;
   } else {
      echo "Failed to create temporary file.";
   }
?> 

Output

This will generate the below output −

Temporary file created: /private/var/folders/92/7wtrqd0j3q95q0_1z2qkl79h0000gn/T/prefix_E2pUqG

Example

In this example we will use tempnam() function to create a temporary file but also we will handle the error if any error occur during the file creation.

<?php
   // Mention the directory 
   $directory = '/tmp';

   // Mention a prefix
   $prefix = 'example_';

   // Create the temporary file
   $temp_file = tempnam($directory, $prefix);

   // Check if the file was created successfully
   if ($temp_file) {
      echo "Temporary file created: " . $temp_file . "\n";
      // Write some data to the temporary file
      file_put_contents($temp_file, "This is some temporary data.");
      echo "Data written to temporary file.\n";
   } else {
      echo "Failed to create temporary file.";
   }
?> 

Output

This will lead to the following output −

If successfully created the file −

Temporary file created: /PhpProjects/example_nI6sX1
Data written to temporary file.

If Failed to create the file −

Failed to create temporary file.

Summary

The tempnam() method is a built-in function to create a temporary file in PHP. It is very helpful to create a temporary file to store data temporarily and it also makes sure unique file names to avoid conflicts.