Time stamp files, filetime, custom css version http://genesissnippets.com/override-css-cache-force-css-chagnes-to-go-live-immediately/
<?php
function custom_style_sheet() {
echo "<link rel='stylesheet' id='custom-style' href='". get_stylesheet_directory_uri() ."/custom.css?". filemtime( get_stylesheet_directory() . '/custom.css') ."' type='text/css' media='all' />"."\n";
} add_action( 'wp_head', 'custom_style_sheet', 999 );
function child_stylesheet_uri( $stylesheet_uri ) {
return add_query_arg( 'v', filemtime( get_stylesheet_directory() . '/style.css' ), $stylesheet_uri );
} add_filter( 'stylesheet_uri', 'child_stylesheet_uri' );
function woo_output_custom_css() {
// If "custom.css" exists in the parent theme, load it.
if ( file_exists( get_template_directory() . '/custom.css' ) ) {
echo "\n" . '<!-- Custom Stylesheet -->' . "\n" . '<link href="'. esc_url( get_template_directory_uri() . '/custom.css' . '?' . filemtime( get_stylesheet_directory() . '/custom.css') ) . '" rel="stylesheet" type="text/css" />' . "\n";
}
} // End woo_output_custom_css()
?>
<link rel="stylesheet" type="text/css" href="<?php echo bloginfo('stylesheet_url'). '?' . filemtime( get_stylesheet_directory() . '/style.css'); ?>" />