wppaste
WordPress

sanitize_user( string $username, bool $strict = false ): string

Since
2.0.0
Source
wp-includes/formatting.php:2149
Sanitizes a username, stripping out unsafe characters.

Description

Removes tags, percent-encoded characters, HTML entities, and if strict is enabled, will only keep alphanumeric, _, space, ., -, @. After sanitizing, it passes the username, raw username (the username in the parameter), and the value of $strict as parameters for the 'sanitize_user' filter.

Compatibility

WordPress
since 2.0.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

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

Parameters

$usernamestring
The username to be sanitized.
$strictbooloptional
If set to true, limits $username to specific characters.
Default false.Default: false

Return value

string
The sanitized username, after passing through filters.

Performance profile

How much work a call to sanitize_user() 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
Trivial

Touches nothing outside its own arguments.

Scaling
Constant

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

Instructions
30–33

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 33.

Plugin surface
1 hook

Third-party callbacks on 'sanitize_user' run inside this call, and their cost is not bounded by anything here.

Called by
10

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

What it touches

  • hookthird-party callbacksapply_filters()called directly

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

What one call costs · 1 distinct outcome

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

WhenInstructionsCalls it makes
always30–33wp_strip_all_tags(), remove_accents(), apply_filters()

Across PHP versions

PHPCompiledExecutedBranchesNotes
8.6-dev3330–331
8.53330–331
8.43330–33114 fewer instructions than PHP 8.3
8.34741–471
8.24741–471
8.14741–471
7.44741–471

An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.

Hooks and filters fired · 1

One hook fires while sanitize_user() runs, in this order:

  1. apply_filters( sanitize_user )filterline 2176 (+27 into the body)

    Filters a sanitized username string.

Uses · 3

Used by · 10

Source code

function sanitize_user( $username, $strict = false ) {	$raw_username = $username;	$username     = wp_strip_all_tags( $username );	$username     = remove_accents( $username );	// Remove percent-encoded characters.	$username = preg_replace( '|%([a-fA-F0-9][a-fA-F0-9])|', '', $username );	// Remove HTML entities.	$username = preg_replace( '/&.+?;/', '', $username ); 	// If strict, reduce to ASCII for max portability.	if ( $strict ) {		$username = preg_replace( '|[^a-z0-9 _.\-@]|i', '', $username );	} 	$username = trim( $username );	// Consolidate contiguous whitespace.	$username = preg_replace( '|\s+|', ' ', $username ); 	/**	 * Filters a sanitized username string.	 *	 * @since 2.0.1	 *	 * @param string $username     Sanitized username.	 * @param string $raw_username The username prior to sanitization.	 * @param bool   $strict       Whether to limit the sanitization to specific characters.	 */	return apply_filters( 'sanitize_user', $username, $raw_username, $strict );}

Changelog

Introduced in 2.0.0. 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 7.1.0 tag, from src/wp-includes/formatting.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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