PHP中一些可用的方法

/*

return Array

$in_charset原字符串编码

$out_charset输出字符串编码

$arr传入的数组

*/

function array_iconv($in_charset,$out_charset,$arr){   

    eval('$resArr = '.iconv($in_charset,$out_charset."//IGNORE",var_export($arr,true)).' ;');
    return $resArr;
}

/*

$arr输入的二位数组

$keys需要排序的字段

$mode是否保持原来的键名，keep为保持、nokeep为重新建立

$type排序方式 asc为升序。desc为降序

*/

function array_sort($arr,$keys,$mode='nokeep',$type='asc'){   

      $keysvalue = $new_array = array();

      foreach ($arr as $k=>$v){

            $keysvalue[$k] = iconv('UTF-8', 'GB2312',$v[$keys]);

       }

       if($type == 'asc'){

            asort($keysvalue);

       }else{

             arsort($keysvalue);

        }

        reset($keysvalue);

        if($mode=='keep'){

        foreach ($keysvalue as $k=>$v){

              $new_array[$k] = $arr[$k];

         }

        }else{

             foreach ($keysvalue as $k=>$v){

             $new_array[] = $arr[$k];

        }

   }
    return $new_array; 

}

/*

$url远程地址

*/

function curl_get_contents($url){

    $ch = curl_init();

    curl_setopt($ch, CURLOPT_URL, $url);            //设置访问的url地址

    //curl_setopt($ch,CURLOPT_HEADER,1);            //是否显示头部信息

    curl_setopt($ch, CURLOPT_TIMEOUT, 5);           //设置超时

    curl_setopt($ch, CURLOPT_USERAGENT, _USERAGENT_);   //用户访问代理 User-Agent

    curl_setopt($ch, CURLOPT_REFERER,_REFERER_);        //设置 referer

    curl_setopt($ch,CURLOPT_FOLLOWLOCATION,1);      //跟踪301

    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);       //返回结果

    $r = curl_exec($ch);

    curl_close($ch);

    return $r;

}

 /*
    $filename下载文件地址或路径
    */
    function download($filename){
        if(preg_match("/^http\:\/\//i",$filename)){
            header("location:$filename");
        }else{
            header('Content-Description: File Transfer');
            header('Content-Type: application/octet-stream');
            $simplename = basename($filename);
            header('Content-Disposition: attachment; filename='.$simplename);
            header('Content-Transfer-Encoding: binary');
            header('Expires: 0');
            header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
            header('Pragma: public');
            header('Content-Length: ' . filesize($filename));
            ob_clean();
            flush();
            readfile($filename);
        }
    }

    /*
    return String
    $num生成位数
    $mode模式，1为生成大写与数字，2为生成大小写与数字
    */

    function randnum($num,$mode=1){
        if($mode==1){
            $str_abc = '1234567890ABCDEFGHIJKLOMNOPQRSTUVWXYZ';
            $str = '';
            for($i=0;$i<$num;$i++){
                $str .= $str_abc{mt_rand(0,35)};
            }
            return $str;
            $str = '';
        }else{
            $str_abc = '1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLOMNOPQRSTUVWXYZ';
            $str = '';
            for($i=0;$i<$num;$i++){
                $str .= $str_abc{mt_rand(0,61)};
            }
            return $str;
            $str = '';
        }
    }

/*
     return String
     $str传入的字符
     $start起始位置
     $start结束位置
     */

    function cSubstr($str,$start,$len)
    {
        for ($i = $start; $i < $len; $i++) {
            $temp_str = substr($str, 0, 1);
            if (ord($temp_str) > 127) {
                $i++;
                if ($i < $len) {
                    $new_str[] = substr($str, 0, 3);
                    $str = substr($str, 3);
                }
            } else {
                $new_str[] = substr($str, 0, 1);
                $str = substr($str, 1);
            }
            return join($new_str);
        }
    }