PHP根據IP地址獲取所在城市具體實現
了PHP根據IP地址獲取所在城市具體實現,有需要的朋友可以參考一下,就讓小編來告訴大家吧!
文件目錄:
ipLocation
-----qqwry
文件代碼:
複製代碼 代碼如下:
<?php
class ipCity {
/**
* 根據ip地址獲取對應所在城市
* @param type $userip 用户IP地址
* @return string
*/
public function getCity( $userip, $dat_path = '' ) {
//IP數據庫路徑,這裏用的是QQ IP數據庫 20110405 純真版
empty( $dat_path ) && $dat_path = FCPATH . 'plugin/ipLocation/qqwry/';
//判斷IP地址是否有效
if ( preg_match( "/^([0-9]{1,3}.){3}[0-9]{1,3}$/", $userip ) == 0 ) {
return 'IP Address Invalid';
}
//打開IP數據庫
if ( !$fd = @fopen( $dat_path, 'rb' ) ) {
return 'IP data file not exists or access denied';
}
//explode函數分解IP地址,運算得出整數形結果
$userip = explode( '.', $userip );
$useripNum = $userip[0] * 16777216 + $userip[1] * 65536 + $userip[2] * 256 + $userip[3];
//獲取IP地址索引開始和結束位置
$DataBegin = fread( $fd, 4 );
$DataEnd = fread( $fd, 4 );
$useripbegin = implode( '', unpack( 'L', $DataBegin ) );
if ( $useripbegin < 0 )
$useripbegin += pow( 2, 32 );
$useripend = implode( '', unpack( 'L', $DataEnd ) );
if ( $useripend < 0 )
$useripend += pow( 2, 32 );
$useripAllNum = ($useripend - $useripbegin) / 7 + 1;
$BeginNum = 0;
$EndNum = $useripAllNum;
//使用二分查找法從索引記錄中搜索匹配的'IP地址記錄
while ( $userip1num > $useripNum || $userip2num < $useripNum ) {
$Middle = intval( ($EndNum + $BeginNum) / 2 );
//偏移指針到索引位置讀取4個字節
fseek( $fd, $useripbegin + 7 * $Middle );
$useripData1 = fread( $fd, 4 );
if ( strlen( $useripData1 ) < 4 ) {
fclose( $fd );
return 'File Error';
}
//提取出來的數據轉換成長整形,如果數據是負數則加上2的32次冪
$userip1num = implode( '', unpack( 'L', $useripData1 ) );
if ( $userip1num < 0 )
$userip1num += pow( 2, 32 );
//提取的長整型數大於我們IP地址則修改結束位置進行下一次循環
if ( $userip1num > $useripNum ) {
$EndNum = $Middle;
continue;
}
//取完上一個索引後取下一個索引
$DataSeek = fread( $fd, 3 );
if ( strlen( $DataSeek ) < 3 ) {
fclose( $fd );
return 'File Error';
}
$DataSeek = implode( '', unpack( 'L', $DataSeek . chr( 0 ) ) );
fseek( $fd, $DataSeek );
$useripData2 = fread( $fd, 4 );
if ( strlen( $useripData2 ) < 4 ) {
fclose( $fd );
return 'File Error';
}
$userip2num = implode( '', unpack( 'L', $useripData2 ) );
if ( $userip2num < 0 )