php 取得访问者信息,基本函数

<?php
/**
* 取得访问者信息，公用函数
* @author zhuyubing@gmail.com
*/

function prep($var)
{
return (isset(＄＿SERVER[$var])) ? (trim(＄＿SERVER[$var])) : '';
}
/**
* 获取用户ip
*
* @return string
*/
function ip_prep()
{
$ip = '';
if (getenv('HTTP_CLIENT_IP')) {
$ip = getenv('HTTP_CLIENT_IP');
} else if (getenv('HTTP_X_FORWARDED_FOR')) {
$ip = getenv('HTTP_X_FORWARDED_FOR');
} else if (getenv('REMOTE_ADDR')) {
$ip = getenv('REMOTE_ADDR');
} else {
$ip =　＄＿SERVER['REMOTE_ADDR'];
}
return $ip;
}
/**
* 获取浏览器类型
*
* @return string
*/
function get_browser(){
$agent =＄＿SERVER['HTTP_USER_AGENT'];
$browser = '';
if(strpos($agent, 'MSIE')) {
if (preg_match("/MSIE ([0-9]\.[0-9]+);/",$agent,$matches)){
$browser = 'Internet Explorer '.$matches[1];
} else {
$browser = 'Internet Explorer (hack)';
}
}elseif(strpos($agent, "NetCaptor")) {
$browser = "NetCaptor";
} elseif(strpos($agent, "Netscape")) {
$browser = "Netscape";
} elseif(strpos($agent, "Lynx")) {
$browser = "Lynx";
} elseif(strpos($agent, "Opera")) {
$browser = "Opera";
} elseif(strpos($agent, "Konqueror")) {
$browser = "Konqueror";
} elseif(strpos($agent, "Mozilla")) {
if (preg_match("/ Firefox\/([0-9](\.[0-9])+)/",$agent,$matches)){
$browser = 'Firefox '.$matches[1];
} else {
$browser = 'Moziila';
}
} else {
$browser = 'other';
}
return $browser;
}
/**
* 获取访问者的操作系统类型
*
* @return unknown
*/
function get_os() {
$os =＄＿SERVER['HTTP_USER_AGENT'];
if(strpos($os,"Windows NT 5.0")) $os="Windows 2000";
elseif(strpos($os,"Windows NT 5.1")) $os="Windows XP";
elseif(strpos($os,"Windows NT 5.2")) $os="Windows 2003";
elseif(strpos($os,"Windows NT 6.0")) $os="Windows Vista";
elseif(strpos($os,"Windows NT")) $os="Windows NT";
elseif(strpos($os,"Windows 9")) $os="Windows 98";
elseif(strpos($os,"unix")) $os="Unix";
elseif(strpos($os,"linux")) $os="Linux";
elseif(strpos($os,"SunOS")) $os="SunOS";
elseif(strpos($os,"BSD")) $os="FreeBSD";
elseif(strpos($os,"Mac")) $os="Mac";
else $os="Other";
return $os;
}
?>