php根据地址的经纬度查询周围的城市例子

//$lat 已知点的纬度
$dlng =  2 * asin(sin($distance / (2 * EARTH_RADIUS)) / cos(deg2rad($lat)));
$dlng = rad2deg($dlng);//转换弧度

$dlat = $distance/EARTH_RADIUS;//EARTH_RADIUS地球半径
$dlat = rad2deg($dlat);//转换弧度

define(EARTH_RADIUS, 6371);//地球半径，平均半径为6371km
 /**
 *计算某个经纬度的周围某段距离的正方形的四个点
 *
 *@param lng float 经度
 *@param lat float 纬度
 *@param distance float 该点所在圆的半径，该圆与此正方形内切，默认值为0.5千米
 *@return array 正方形的四个点的经纬度坐标
 */
 function returnSquarePoint($lng, $lat,$distance = 0.5){
 
    $dlng =  2 * asin(sin($distance / (2 * EARTH_RADIUS)) / cos(deg2rad($lat)));
    $dlng = rad2deg($dlng);
    
    $dlat = $distance/EARTH_RADIUS;
    $dlat = rad2deg($dlat);
    
    return array(
                'left-top'=>array('lat'=>$lat + $dlat,'lng'=>$lng-$dlng),
                'right-top'=>array('lat'=>$lat + $dlat, 'lng'=>$lng + $dlng),
                'left-bottom'=>array('lat'=>$lat - $dlat, 'lng'=>$lng - $dlng),
                'right-bottom'=>array('lat'=>$lat - $dlat, 'lng'=>$lng + $dlng)
                );
 }
//使用此函数计算得到结果后，带入sql查询。

$squares = returnSquarePoint($lng, $lat);
$info_sql = "select id,locateinfo,lat,lng from `lbs_info` where lat<>0 and lat>{$squares['right-bottom']['lat']} and lat<{$squares['left-top']['lat']} and lng>{$squares['left-top']['lng']} and lng<{$squares['right-bottom']['lng']} ";

<?php
     include_once('HttpClient.class.php');
     //目标主机的地址，我这里填上测试的地址
     $Client = new HttpClient("192.168.1.5");
     $url = "http://localhost/receive.php";//请求的页面地址
     //ＰＯＳＴ的参数
     $params = array('username'=>"guowenlong",'password'=>"hahahaha");
     $pageContents = HttpClient::quickPost($url, $params);
     echo $pageContents;
?>

$data = array('hello','word');
$d = "helloword";
$d = str_repeat($d, 10000);
//for($i = 0;$i $data[] = $d;
//}
//var_dump($data);

$jsonen_sarttime = getmicrotime();
for($i=0;$i $json = json_encode($data);

}
echo "json长度:".strlen($json)."
n";
$jsonen_endtime = getmicrotime();
echo "jsonencode耗时:".($jsonen_endtime - $jsonen_sarttime)."
n";

$jsonde_starttime = getmicrotime();
for($i=0;$i $unjson = json_decode($json,true);
}
$jsonde_endtime = getmicrotime();

echo "jsondecode耗时:".($jsonde_endtime - $jsonde_starttime)."
n";

$seri1_starttime = getmicrotime();
for($i=0;$i $serialize = serialize($data);
}
echo "serialize长度:".strlen($serialize)."
n";
$seri1_endtime = getmicrotime();
echo "serialize序列化耗时:".($seri1_endtime - $seri1_starttime)."
n";

$seri2_starttime = getmicrotime();
for($i=0;$i $unserialize = unserialize($serialize);
}
$seri2_endtime = getmicrotime();

echo "serialize反序列化耗时:".($seri2_endtime - $seri2_starttime)."
n";

/**
*获取时间记
* @return
*/
function getmicrotime(){
list($usec, $sec) = explode(" ",microtime());
return ((float)$usec + (float)$sec);
}

$data = array('hello','word');
$d = "你好";
$d = str_repeat($d, 10000);
//for($i = 0;$i $data[] = $d;

$data = array('hello','word');
$d = "你好";
for($i = 0;$i $data[] = $d;
}

$data = array('hello','word');
$d = "hello";
for($i = 0;$i $data[] = $d;
}

<?php
ini_set('memory_limit', '512m');
$array = array_fill(0, 1000000, rand(1, 9999));

$start = microtime(true);
$export = json_encode($array);
$end = microtime(true);
$duration = $end - $start;
print('JSON Encode: ' . $duration . PHP_EOL);

$start = microtime(true);
$import = json_decode($export);
$end = microtime(true);
$duration = $end - $start;
print('JSON Decode: ' . $duration . PHP_EOL);

$start = microtime(true);
$export = serialize($array);
$end = microtime(true);
$duration = $end - $start;
print('Serialize: ' . $duration . PHP_EOL);

$start = microtime(true);
$import = unserialize($export);
$end = microtime(true);
$duration = $end - $start;
print('Serialize: ' . $duration . PHP_EOL);

$start = microtime(true);
$export = igbinary_serialize($array);
$end = microtime(true);
$duration = $end - $start;
print('Igbinary Serialize: ' . $duration . PHP_EOL);

$start = microtime(true);
$import = igbinary_unserialize($export);
$end = microtime(true);
$duration = $end - $start;
print('Igbinary Serialize: ' . $duration . PHP_EOL);
?>

pcntl_exec — 在当前进程空间执行指定程序,代码如下:

$cmds=array(
        array('/home/jerry/projects/www/test2.php'),
        array('/home/jerry/projects/www/test3.php')
);
 
foreach($cmds as $cmd){
        $pid=pcntl_fork();
        if($pid==-1){
        //进程创建失败
            echo '创建子进程失败时返回-1';
            exit(-1);
        }
        else if($pid){
        //父进程会得到子进程号，所以这里是父进程执行的逻辑
            pcntl_wait($status,WNOHANG);
        }
        else{
        //子进程处理逻辑
            sleep(5);
            pcntl_exec('/usr/bin/php',$cmd);
            exit(0);
        }
}