<?php
/**
* Creates common globals for the rest of WordPress
*
* Sets $pagenow global which is the filename of the current screen.
* 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://developer.wordpress.org/advanced-administration/server/web-server/nginx/
*
* @package WordPress
*/

global $pagenow,
$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, $is_caddy;

// On which page are we?
if ( is_admin() ) {
// 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'], $self_matches );
} else {
preg_match( '#/wp-admin/?(.*?)$#i', $_SERVER['PHP_SELF'], $self_matches );
}

$pagenow = ! empty( $self_matches[1] ) ? $self_matches[1] : '';
$pagenow = trim( $pagenow, '/' );
$pagenow = preg_replace( '#\?.*?$#', '', $pagenow );

if ( '' === $pagenow || 'index' === $pagenow || 'index.php' === $pagenow ) {
$pagenow = 'index.php';
} else {
preg_match( '#(.*?)(/|$)#', $pagenow, $self_matches );
$pagenow = strtolower( $self_matches[1] );
if ( ! str_ends_with( $pagenow, '.php' ) ) {
$pagenow .= '.php'; // For `Options +Multiviews`: /wp-admin/themes/index.php (themes.php is queried).
}
}
} else {
if ( preg_match( '#([^/]+\.php)([?/].*?)?$#i', $_SERVER['PHP_SELF'], $self_matches ) ) {
$pagenow = strtolower( $self_matches[1] );
} else {
$pagenow = 'index.php';
}
}
unset( $self_matches );

// Simple browser detection.
$is_lynx = false;
$is_gecko = false;
$is_winIE = false;
$is_macIE = false;
$is_opera = false;
$is_NS4 = false;
$is_safari = false;
$is_chrome = false;
$is_iphone = false;
$is_edge = false;

if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
if ( str_contains( $_SERVER['HTTP_USER_AGENT'], 'Lynx' ) ) {
$is_lynx = true;
} elseif ( str_contains( $_SERVER['HTTP_USER_AGENT'], 'Edg' ) ) {
$is_edge = true;
} elseif ( str_contains( $_SERVER['HTTP_USER_AGENT'], 'Opera' ) || str_contains( $_SERVER['HTTP_USER_AGENT'], 'OPR/' ) ) {
$is_opera = true;
} elseif ( stripos( $_SERVER['HTTP_USER_AGENT'], 'chrome' ) !== false ) {
if ( stripos( $_SERVER['HTTP_USER_AGENT'], 'chromeframe' ) !== false ) {
$is_admin = is_admin();
/**
* Filters whether Google Chrome Frame should be used, if available.
*
* @since 3.2.0
*
* @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 );
if ( $is_chrome ) {
header( 'X-UA-Compatible: chrome=1' );
}
$is_winIE = ! $is_chrome;
} else {
$is_chrome = true;
}
} elseif ( stripos( $_SERVER['HTTP_USER_AGENT'], 'safari' ) !== false ) {
$is_safari = true;
} elseif ( ( str_contains( $_SERVER['HTTP_USER_AGENT'], 'MSIE' ) || str_contains( $_SERVER['HTTP_USER_AGENT'], 'Trident' ) )
&& str_contains( $_SERVER['HTTP_USER_AGENT'], 'Win' )
) {
$is_winIE = true;
} elseif ( str_contains( $_SERVER['HTTP_USER_AGENT'], 'MSIE' ) && str_contains( $_SERVER['HTTP_USER_AGENT'], 'Mac' ) ) {
$is_macIE = true;
} elseif ( str_contains( $_SERVER['HTTP_USER_AGENT'], 'Gecko' ) ) {
$is_gecko = true;
} elseif ( str_contains( $_SERVER['HTTP_USER_AGENT'], 'Nav' ) && str_contains( $_SERVER['HTTP_USER_AGENT'], 'Mozilla/4.' ) ) {
$is_NS4 = true;
}
}

if ( $is_safari && stripos( $_SERVER['HTTP_USER_AGENT'], 'mobile' ) !== false ) {
$is_iphone = true;
}

$is_IE = ( $is_macIE || $is_winIE );

// Server detection.

/**
* Whether the server software is Apache or something else.
*
* @global bool $is_apache
*/
$is_apache = ( str_contains( $_SERVER['SERVER_SOFTWARE'], 'Apache' ) || str_contains( $_SERVER['SERVER_SOFTWARE'], 'LiteSpeed' ) );

/**
* Whether the server software is Nginx or something else.
*
* @global bool $is_nginx
*/
$is_nginx = ( str_contains( $_SERVER['SERVER_SOFTWARE'], 'nginx' ) );

/**
* Whether the server software is Caddy / FrankenPHP or something else.
*
* @global bool $is_caddy
*/
$is_caddy = ( str_contains( $_SERVER['SERVER_SOFTWARE'], 'Caddy' ) || str_contains( $_SERVER['SERVER_SOFTWARE'], 'FrankenPHP' ) );

/**
* Whether the server software is IIS or something else.
*
* @global bool $is_IIS
*/
$is_IIS = ! $is_apache && ( str_contains( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS' ) || str_contains( $_SERVER['SERVER_SOFTWARE'], 'ExpressionDevServer' ) );

/**
* Whether the server software is IIS 7.X or greater.
*
* @global bool $is_iis7
*/
$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.).
*
* @since 3.4.0
* @since 6.4.0 Added checking for the Sec-CH-UA-Mobile request header.
*
* @return bool
*/
function wp_is_mobile() {
if ( isset( $_SERVER['HTTP_SEC_CH_UA_MOBILE'] ) ) {
// This is the `Sec-CH-UA-Mobile` user agent client hint HTTP request header.
// See <https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Sec-CH-UA-Mobile>.
$is_mobile = ( '?1' === $_SERVER['HTTP_SEC_CH_UA_MOBILE'] );
} elseif ( empty( $_SERVER['HTTP_USER_AGENT'] ) ) {
$is_mobile = false;
} elseif ( str_contains( $_SERVER['HTTP_USER_AGENT'], 'Mobile' ) // Many mobile devices (all iPhone, iPad, etc.)
|| str_contains( $_SERVER['HTTP_USER_AGENT'], 'Android' )
|| str_contains( $_SERVER['HTTP_USER_AGENT'], 'Silk/' )
|| str_contains( $_SERVER['HTTP_USER_AGENT'], 'Kindle' )
|| str_contains( $_SERVER['HTTP_USER_AGENT'], 'BlackBerry' )
|| str_contains( $_SERVER['HTTP_USER_AGENT'], 'Opera Mini' )
|| str_contains( $_SERVER['HTTP_USER_AGENT'], 'Opera Mobi' ) ) {
$is_mobile = true;
} else {
$is_mobile = false;
}

/**
* Filters whether the request should be treated as coming from a mobile device or not.
*
* @since 4.9.0
*
* @param bool $is_mobile Whether the request is from a mobile device or not.
*/
return apply_filters( 'wp_is_mobile', $is_mobile );
}