根据IP获取访客所在国家/城市/经纬度
安装GeoIP扩展：
sudo apt-get install libgeoip-dev
pecl install geoip-1.1.0
注意:Beta版要指定版本号.如果是apt安装的PHP,直接安装php5-geoip这个包即可.
php.ini中加入:
extension=geoip.so geoip.custom_directory="/usr/share/GeoIP"
免费下载GeoLiteCity数据库(解压后18MB):
http://dev.maxmind.com/geoip/legacy/install/city/
wget http://geolite.maxmind.com/download/geoip/database/GeoLiteCity.dat.gz gunzip GeoLiteCity.dat.gz sudo mkdir -v /usr/share/GeoIP sudo mv -v GeoLiteCity.dat /usr/share/GeoIP/GeoIPCity.dat
测试:
php -a
<?php
print_r(geoip_record_by_name('106.37.165.80')); //回车后按Ctrl D运行
Array
(
[continent_code] => AS
[country_code] => CN
[country_code3] => CHN
[country_name] => China //国家
[region] => 22
[city] => Beijing //城市
[postal_code] =>
[latitude] => 39.928901672363 //纬度
[longitude] => 116.38829803467 //经度
[dma_code] => 0
[area_code] => 0
)
在命令行用geoiplookup查看IP信息:
traceroute www.oschina.net
可见IP地址
61.145.122.155
sudo apt-get install geoip-bin geoip-database geoiplookup 61.145.122.155 -f /usr/share/GeoIP/GeoIP.dat GeoIP Country Edition: CN, China
geoip-database提供的GeoIP.dat只能精确到国家.
geoiplookup 61.145.122.155 -f /usr/share/GeoIP/GeoIPCity.dat GeoIP City Edition, Rev 1: CN, 30, Guangdong, Guangzhou, N/A, 23.116699, 113.250000, 0, 0
从maxmind官网下的数据库GeoLiteCity则信息更详细.
geoiplookup 61.145.122.155 则同时显示上述两个数据库的信息.
根据IP确定经纬度与计算距离
可以用
geoip_record_by_name($_SERVER['REMOTE_ADDR'])
根据用户IP确定经纬度.
注意:
geoip_record_by_name()
返回的西经和南纬是负数.
5000米转成经纬度:
纬度 Latitude: 1 deg = 110852 m
经度 Longitude: 1 deg = 111320*cos(lat) m
同一经线上,相差一纬度约为 110852 米
同一纬线上,相差一经度约为 111320*cos(lat) 米 (lat为该纬线的纬度)
<?php //以当前用户经纬度为中心,查询5000米内的其他用户 $y = 5000 / 110852; //纬度的范围 $x = 5000 / (111320*cos($lat)); //经度的范围 $sql = ' select * from user where lat >= ($lat-$y) and lat <= ($lat $y) and lon >= ($lon-$x) and lon <= ($lon $x); ';
数据库用户表中设两个字段,分别存储用户的经度lat和纬度lon.
($lat-$y) <= lat <= ($lat $y) ($lon-$x) <= lon <= ($lon $x)
这个范围是一个粗略的范围,下面计算距离后把超过5公里的用户去掉即可.
根据上面查询出来的用户的经纬度,
用半正矢公式(Haversine)根据经纬度计算两点间距离:
<?php
function distance($lat1, $lon1, $lat2, $lon2) {
$R = 6371393; //地球平均半径,单位米
$dlat = deg2rad($lat2-$lat1);
$dlon = deg2rad($lon2-$lon1);
$a = pow(sin($dlat/2), 2) cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * pow(sin($dlon/2), 2);
$c = 2 * atan2(sqrt($a), sqrt(1-$a));
$d = $R * $c;
return round($d);
}
echo distance(0, 0, -1, 0); // 111202米
然后就可以用uasort或array_multisort由近到远列出用户了,比如有名为win,osx,lin这3个用户:
<?php
$arr = array(
'win' => array(
'dis' => 1024,
'age' => 31
),
'osx' => array(
'dis' => 512,
'age' => 15
),
'lin' => array(
'dis' => 512,
'age' => 25
)
);
foreach($arr as $k => $v) {
$sort['dis'][$k] = $v['dis'];
$sort['age'][$k] = $v['age'];
}
//先按距离升序排序,如果距离相同,则按年龄降序排序
array_multisort($sort['dis'], SORT_ASC, $sort['age'], SORT_DESC, $arr);
echo json_encode($arr);
//{"lin":{"dis":512,"age":25},"osx":{"dis":512,"age":15},"win":{"dis":1024,"age":31}}