<?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://wordpress.org/documentation/article/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;

// 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'], $Telf_matches );
  } elseif ( is_user_admin() ) {
    preg_match( '#/wp-admin/user/?(.*?)$#i', $_SERVER['PHP_SELF'], $Telf_matches );
  } else {
    preg_match( '#/wp-admin/?(.*?)$#i', $_SERVER['PHP_SELF'], $Telf_matches );
  }

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

  if ( '' === $pagenow || 'index' === $pagenow || 'index.php' === $pagenow ) {
    $pagenow = 'index.php';
  } else {
    preg_match( '#(.*?)(/|$)#', $pagenow, $Telf_matches );
    $pagenow = strtolower( $Telf_matches[1] );
    if ( '.php' !== substr( $pagenow, -4, 4 ) ) {
      $pagenow .= '.php'; // For `Options +Multiviews`: /wp-admin/themes/index.php (themes.php is queried).
    }
  }
} else {
  if ( preg_match( '#([^/]+\.php)([?/].*?)?$#i', $_SERVER['PHP_SELF'], $Telf_matches ) ) {
    $pagenow = strtolower( $Telf_matches[1] );
  } else {
    $pagenow = 'index.php';
  }
}
unset( $Telf_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 ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Lynx' ) !== false ) {
    $is_lynx = true;
  } elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Edg' ) !== false ) {
    $is_edge = 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 ( ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE' ) !== false || strpos( $_SERVER['HTTP_USER_AGENT'], 'Trident' ) !== false ) && strpos( $_SERVER['HTTP_USER_AGENT'], 'Win' ) !== false ) {
    $is_winIE = true;
  } elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE' ) !== false && strpos( $_SERVER['HTTP_USER_AGENT'], 'Mac' ) !== false ) {
    $is_macIE = true;
  } elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Gecko' ) !== false ) {
    $is_gecko = true;
  } elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Opera' ) !== false ) {
    $is_opera = true;
  } elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Nav' ) !== false && strpos( $_SERVER['HTTP_USER_AGENT'], 'Mozilla/4.' ) !== false ) {
    $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 = ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Apache' ) !== false || strpos( $_SERVER['SERVER_SOFTWARE'], 'LiteSpeed' ) !== false );


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


/**
 * Whether the server software is IIS or something else
 *
 * @global bool $is_IIS
 */
$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
 *
 * @global bool $is_iis7
 */
$is_iis7 = $is_IIS && (int) substr( $_SERVER['SERVER_SOFTWARE'], strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/' ) + 14 ) >= 7;

/* function wp_is_mobile() – Test if the current browser runs on a mobile device (smart phone, tablet, etc.) */