wp_tempnam() │ WP 2.6.0

Returns a filename of a Temporary unique file. Please note that the calling function must unlink() this itself.

Please note that the calling function must delete or move the file.

The filename is based off the passed parameter or defaults to the current unix timestamp, while the directory can either be passed as well, or by leaving it blank, default to a writable temporary directory.

Used By: download_url()
1 time — 0.000405 sec (fast) | 50000 times — 5.08 sec (fast) | PHP 7.1.11, WP 4.9.5

No Hooks.

Return

String. A writable filename.

Usage

wp_tempnam( $filename, $dir );
$filename(string)
Filename to base the Unique file off.
Default: ''
$dir(string)
Directory to store the file in.
Default: ''

Examples

0

#1 Example of what the function outputs 

require_once ABSPATH . 'wp-admin/includes/file.php';

$filename = wp_tempnam(); //> /tmp/1524879129-OkwJkv.tmp

// modify the file and do something with it

unlink( $filename ); // delete the file

More examples:

$filename = wp_tempnam( 'my_log_file' );     //> /tmp/my_log_file-BmwSQw.tmp
unlink( $filename );

$filename = wp_tempnam( 'my_log_file.log' ); //> /tmp/my_log_file-AreTYU.tmp
unlink( $filename );

$filename = wp_tempnam( '', $_SERVER['DOCUMENT_ROOT'].'/' ); //> /home/example.com/public_html/1524879213-ieQsRX.tmp
unlink( $filename );

Changelog

Since 2.6.0 Introduced.

wp_tempnam() code WP 6.5.2

wp-admin/includes/file.php 
function wp_tempnam( $filename = '', $dir = '' ) {
	if ( empty( $dir ) ) {
		$dir = get_temp_dir();
	}

	if ( empty( $filename ) || in_array( $filename, array( '.', '/', '\\' ), true ) ) {
		$filename = uniqid();
	}

	// Use the basename of the given file without the extension as the name for the temporary directory.
	$temp_filename = basename( $filename );
	$temp_filename = preg_replace( '|\.[^.]*$|', '', $temp_filename );

	// If the folder is falsey, use its parent directory name instead.
	if ( ! $temp_filename ) {
		return wp_tempnam( dirname( $filename ), $dir );
	}

	// Suffix some random data to avoid filename conflicts.
	$temp_filename .= '-' . wp_generate_password( 6, false );
	$temp_filename .= '.tmp';
	$temp_filename  = wp_unique_filename( $dir, $temp_filename );

	/*
	 * Filesystems typically have a limit of 255 characters for a filename.
	 *
	 * If the generated unique filename exceeds this, truncate the initial
	 * filename and try again.
	 *
	 * As it's possible that the truncated filename may exist, producing a
	 * suffix of "-1" or "-10" which could exceed the limit again, truncate
	 * it to 252 instead.
	 */
	$characters_over_limit = strlen( $temp_filename ) - 252;
	if ( $characters_over_limit > 0 ) {
		$filename = substr( $filename, 0, -$characters_over_limit );
		return wp_tempnam( $filename, $dir );
	}

	$temp_filename = $dir . $temp_filename;

	$fp = @fopen( $temp_filename, 'x' );

	if ( ! $fp && is_writable( $dir ) && file_exists( $temp_filename ) ) {
		return wp_tempnam( $filename, $dir );
	}

	if ( $fp ) {
		fclose( $fp );
	}

	return $temp_filename;
}

File system (create delete files folders)

path (directory folder)

Helper Functions