WordPress at a glance
function is not described

wp_cache_clean_expired() WPSCache 1.0

No Hooks.

Return

Null. Nothing.

Usage

wp_cache_clean_expired( $file_prefix );

Code of wp_cache_clean_expired() WPSCache 1.7.1

<?php
function wp_cache_clean_expired($file_prefix) {
	global $cache_max_time, $blog_cache_dir, $wp_cache_preload_on;

	if ( $cache_max_time == 0 ) {
		return false;
	}

	// If phase2 was compiled, use its function to avoid race-conditions
	if(function_exists('wp_cache_phase2_clean_expired')) {
		if ( $wp_cache_preload_on != 1 && function_exists ('prune_super_cache')) {
			$dir = get_supercache_dir();
			if( is_dir( $dir ) ) {
				prune_super_cache( $dir );
			} elseif( is_dir( $dir . '.disabled' ) ) {
				prune_super_cache( $dir . '.disabled' );
			}
			$_POST[ 'super_cache_stats' ] = 1; // regenerate super cache stats;
		}
		return wp_cache_phase2_clean_expired($file_prefix);
	}

	$now = time();
	if ( $handle = @opendir( $blog_cache_dir ) ) {
		while ( false !== ( $file = readdir( $handle ) ) ) {
			if ( strpos( $file, $file_prefix ) !== false ) {
				if ( strpos( $file, '.html' ) ) {
					@unlink( $blog_cache_dir . $file);
					@unlink( $blog_cache_dir . 'meta/' . str_replace( '.html', '.meta', $file ) );
				} elseif ( ( filemtime( $blog_cache_dir . $file ) + $cache_max_time ) <= $now ) {
					@unlink( $blog_cache_dir . $file );
					@unlink( $blog_cache_dir . 'meta/' . $file );
				}
			}
		}
		closedir($handle);
	}
}