wp_tempnam( string $filename = '', string $dir = '' ): string

Description

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$filenamestringoptional

Filename to base the Unique file off. Default empty.Default: ''

$dirstringoptional

Directory to store the file in. Default empty.Default: ''

Return value

string

A writable filename.

Performance profile

How much work a call to wp_tempnam() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Heavy

Reads or writes the filesystem via fopen().

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

22–61

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 81.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

8

8 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• filesystemfilesystem accessfopen()called directly
• hookthird-party callbacksapply_filters()one call below wp_tempnam()

Further down the call graph this can also reach transient, cache, option, serialize and query. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 32 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_tempnam() can have, taken from its control-flow graph on PHP 8.5.

Uses · 4

• get_temp_dir()Determines a writable directory for temporary files.
• wp_tempnam()Returns a filename of a temporary unique file.
• wp_generate_password()Generates a random password drawn from the defined set of characters.
• wp_unique_filename()Gets a filename that is sanitized and unique for the given directory.

Used by · 8

• WP_Customize_Manager::import_theme_starter_content()Imports theme starter content into the customized state.
• WP_Filesystem_FTPext::get_contents()Reads entire file into a string.
• WP_Filesystem_FTPext::put_contents()Writes a string to a file.
• WP_Filesystem_ftpsockets::get_contents()Reads entire file into a string.
• WP_Filesystem_ftpsockets::put_contents()Writes a string to a file.
• WP_REST_Attachments_Controller::upload_from_data()Handles an upload via raw POST data.
• download_url()Downloads a URL to a local temporary file using the WordPress HTTP API.
• wp_tempnam()Returns a filename of a temporary unique file.

Source code

View on Trac ↗View on GitHub ↗

671function wp_tempnam( $filename = '', $dir = '' ) {672	if ( empty( $dir ) ) {673		$dir = get_temp_dir();674	}675 676	if ( empty( $filename ) || in_array( $filename, array( '.', '/', '\\' ), true ) ) {677		$filename = uniqid();678	}679 680	// Use the basename of the given file without the extension as the name for the temporary directory.681	$temp_filename = basename( $filename );682	$temp_filename = preg_replace( '|\.[^.]*$|', '', $temp_filename );683 684	// If the folder is falsey, use its parent directory name instead.685	if ( ! $temp_filename ) {686		return wp_tempnam( dirname( $filename ), $dir );687	}688 689	// Suffix some random data to avoid filename conflicts.690	$temp_filename .= '-' . wp_generate_password( 6, false );691	$temp_filename .= '.tmp';692	$temp_filename  = wp_unique_filename( $dir, $temp_filename );693 694	/*695	 * Filesystems typically have a limit of 255 characters for a filename.696	 *697	 * If the generated unique filename exceeds this, truncate the initial698	 * filename and try again.699	 *700	 * As it's possible that the truncated filename may exist, producing a701	 * suffix of "-1" or "-10" which could exceed the limit again, truncate702	 * it to 252 instead.703	 */704	$characters_over_limit = strlen( $temp_filename ) - 252;705	if ( $characters_over_limit > 0 ) {706		$filename = substr( $filename, 0, -$characters_over_limit );707		return wp_tempnam( $filename, $dir );708	}709 710	$temp_filename = $dir . $temp_filename;711 712	$fp = @fopen( $temp_filename, 'x' );713 714	if ( ! $fp && is_writable( $dir ) && file_exists( $temp_filename ) ) {715		return wp_tempnam( $filename, $dir );716	}717 718	if ( $fp ) {719		fclose( $fp );720	}721 722	return $temp_filename;723}

Changelog

Introduced in 2.6.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.9.7 tag, from src/wp-admin/includes/file.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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