* Creates common globals for the rest of WordPress
* Sets $pagenow global which is the current page. Checks
* for the browser to set which one is currently being used.
* Detects which user environment WordPress is being used on.
* Only attempts to check for Apache, Nginx and IIS -- three web
* servers with known pretty permalink capability.
* Note: Though Nginx is detected, WordPress does not currently
* generate rewrite rules for it. See https://wordpress.org/support/article/nginx/
$is_lynx, $is_gecko, $is_winIE, $is_macIE, $is_opera, $is_NS4, $is_safari, $is_chrome, $is_iphone, $is_IE, $is_edge,
$is_apache, $is_IIS, $is_iis7, $is_nginx;
// wp-admin pages are checked more carefully.
if ( is_network_admin() ) {
preg_match( '#/wp-admin/network/?(.*?)$#i', $_SERVER['PHP_SELF'], $self_matches );
} elseif ( is_user_admin() ) {
preg_match( '#/wp-admin/user/?(.*?)$#i', $_SERVER['PHP_SELF'], $self_matches );
preg_match( '#/wp-admin/?(.*?)$#i', $_SERVER['PHP_SELF'], $self_matches );
$pagenow = $self_matches[1];
$pagenow = trim( $pagenow, '/' );
$pagenow = preg_replace( '#\?.*?$#', '', $pagenow );
if ( '' === $pagenow || 'index' === $pagenow || 'index.php' === $pagenow ) {
preg_match( '#(.*?)(/|$)#', $pagenow, $self_matches );
$pagenow = strtolower( $self_matches[1] );
if ( '.php' !== substr( $pagenow, -4, 4 ) ) {
$pagenow .= '.php'; // For `Options +Multiviews`: /wp-admin/themes/index.php (themes.php is queried).
if ( preg_match( '#([^/]+\.php)([?/].*?)?$#i', $_SERVER['PHP_SELF'], $self_matches ) ) {
$pagenow = strtolower( $self_matches[1] );
// Simple browser detection.
if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
if ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Lynx' ) !== false ) {
} elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Edge' ) !== false ) {
} elseif ( stripos( $_SERVER['HTTP_USER_AGENT'], 'chrome' ) !== false ) {
if ( stripos( $_SERVER['HTTP_USER_AGENT'], 'chromeframe' ) !== false ) {
* Filters whether Google Chrome Frame should be used, if available.
* @param bool $is_admin Whether to use the Google Chrome Frame. Default is the value of is_admin().
$is_chrome = apply_filters( 'use_google_chrome_frame', $is_admin );
header( 'X-UA-Compatible: chrome=1' );
$is_winIE = ! $is_chrome;
} elseif ( stripos( $_SERVER['HTTP_USER_AGENT'], 'safari' ) !== false ) {
} elseif ( ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE' ) !== false || strpos( $_SERVER['HTTP_USER_AGENT'], 'Trident' ) !== false ) && strpos( $_SERVER['HTTP_USER_AGENT'], 'Win' ) !== false ) {
} elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE' ) !== false && strpos( $_SERVER['HTTP_USER_AGENT'], 'Mac' ) !== false ) {
} elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Gecko' ) !== false ) {
} elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Opera' ) !== false ) {
} elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Nav' ) !== false && strpos( $_SERVER['HTTP_USER_AGENT'], 'Mozilla/4.' ) !== false ) {
if ( $is_safari && stripos( $_SERVER['HTTP_USER_AGENT'], 'mobile' ) !== false ) {
$is_IE = ( $is_macIE || $is_winIE );
* Whether the server software is Apache or something else
* @global bool $is_apache
$is_apache = ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Apache' ) !== false || strpos( $_SERVER['SERVER_SOFTWARE'], 'LiteSpeed' ) !== false );
* Whether the server software is Nginx or something else
$is_nginx = ( strpos( $_SERVER['SERVER_SOFTWARE'], 'nginx' ) !== false );
* Whether the server software is IIS or something else
$is_IIS = ! $is_apache && ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS' ) !== false || strpos( $_SERVER['SERVER_SOFTWARE'], 'ExpressionDevServer' ) !== false );
* Whether the server software is IIS 7.X or greater
$is_iis7 = $is_IIS && (int) substr( $_SERVER['SERVER_SOFTWARE'], strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/' ) + 14 ) >= 7;
* Test if the current browser runs on a mobile device (smart phone, tablet, etc.)
function wp_is_mobile() {
if ( empty( $_SERVER['HTTP_USER_AGENT'] ) ) {
} elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Mobile' ) !== false // Many mobile devices (all iPhone, iPad, etc.)
|| strpos( $_SERVER['HTTP_USER_AGENT'], 'Android' ) !== false
|| strpos( $_SERVER['HTTP_USER_AGENT'], 'Silk/' ) !== false
|| strpos( $_SERVER['HTTP_USER_AGENT'], 'Kindle' ) !== false
|| strpos( $_SERVER['HTTP_USER_AGENT'], 'BlackBerry' ) !== false
|| strpos( $_SERVER['HTTP_USER_AGENT'], 'Opera Mini' ) !== false
|| strpos( $_SERVER['HTTP_USER_AGENT'], 'Opera Mobi' ) !== false ) {
* Filters whether the request should be treated as coming from a mobile device or not.
* @param bool $is_mobile Whether the request is from a mobile device or not.
return apply_filters( 'wp_is_mobile', $is_mobile );