Get visitor operating system

Get visitor operating system

function osinfo() {
$os="";
$Agent = $GLOBALS["HTTP_USER_AGENT"];
if (eregi('win',$Agent) && strpos($Agent, '95')) { //OsPHP.COM.CN
$os="Windows 95";
}
elseif (eregi('win 9x',$Agent) && strpos($Agent, '4.90')) {
 $os="Windows ME";
}
elseif (eregi('win',$Agent) && ereg('98',$Agent)) {
//Open source OSPhP.COM.CN
$os="Windows 98 ";
}
elseif (eregi('win',$Agent) && eregi('nt 5.0',$Agent)) {
$os="Windows 2000";
}
elseif (eregi('win',$ Agent) && eregi('nt',$Agent)) {
//OSPHP.COM.CnOpen Source
$os="Windows NT";
}
elseif (eregi('win',$Agent) && eregi(' nt 5.1',$Agent)) {
$os="Windows XP";
}
elseif (eregi('win',$Agent) && ereg('32',$Agent)) {
//Open source OSPhP. COM.CN
$os="Windows 32";
}
elseif (eregi('linux',$Agent)) {
$os="Linux";
}
elseif (eregi('unix',$Agent) ) {
$os="Unix"; //PHP open source code
}
elseif (eregi('sun',$Agent) && eregi('os',$Agent)) {
$os="SunOS";
 }
elseif (eregi('ibm',$Agent) && eregi('os',$Agent)) { //OSPHP.COm.CN
$os="IBM OS/2";
}
elseif (eregi( 'Mac',$Agent) && eregi('PC',$Agent)) {
$os="Macintosh";
}
elseif (eregi('PowerPC',$Agent)) { //OSPHP.com.CN
$os="PowerPC";
}
elseif (eregi('AIX',$Agent)) {
$os="AIX";
}
elseif (eregi('HPUX',$Agent)) {
$ os="HPUX";
//Open source code OSPhP.COm.CN
}
elseif (eregi('NetBSD',$Agent)) {
$os="NetBSD";
}
elseif (eregi('BSD' ,$Agent)) {
$os="BSD";
}
elseif (ereg('OSF1',$Agent)) {
//Open source code OSPHP.COM.Cn
$os="OSF1";
}
elseif (ereg('IRIX',$Agent)) {
$os="IRIX";
}
elseif (eregi('FreeBSD',$Agent)) {
$os="FreeBSD";
//oSPHP .COM.CN
}
if ($os=='') $os = "Unknown";
return $os;
}
//Call method $os=os_infor();
?>