function.php

//check whether it is ajax
function isAjax(){  
       if(isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH'])=='xmlhttprequest'){   
           return true;  
       }else{   
           return false;  
       };  
   }

//check the upload files' extension and http uploaded
function check_upload($file) {
		$ext = strtolower(pathinfo($file['name'], PATHINFO_EXTENSION));
		$contentType = $file['type'];
		if (is_uploaded_file($file['tmp_name']) && $ext == 'txt' && $contentType == 'text/plain' && $file['error'] == 0) {
			return true;
		} else {
			return false;
		}
	}
 
 //recursivly make directory
 function mk_dirs($dir) {
		return is_dir($dir) or (mk_dirs(dirname($dir)) and mkdir($dir, 0777));
	}
  
  function get_ip() {
		//strcasecmp 比较两个字符，不区分大小写。返回0，>0，<0。
		if (getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {
			$ip = getenv('HTTP_CLIENT_IP');
		} elseif (getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {
			$ip = getenv('HTTP_X_FORWARDED_FOR');
		} elseif (getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {
			$ip = getenv('REMOTE_ADDR');
		} elseif (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {
			$ip = $_SERVER['REMOTE_ADDR'];
		}
		$res = preg_match('/[\d\.]{7,15}/', $ip, $matches) ? $matches[0] : '';
		return $res;
	}
  
  
    function trim_data($data) {
		  $data = trim($data);
		  $data = htmlspecialchars($data);
		  $data = strip_tags($data);
		  if(!get_magic_quotes_gpc()){
			  $data = addslashes($data);
		   }
		  return $data;
	}
	function showPage($page,$totalPage,$sep=" "){  
	    $url = $_SERVER ['PHP_SELF'];           //获取当前路径  
	    $index = ($page == 1) ? "首页" : "<a href='{$url}?page=1'>首页</a>";  
	    $last = ($page == $totalPage) ? "尾页" : "<a href='{$url}?page={$totalPage}'>尾页</a>";  
	    $prevPage=($page>=1)?$page-1:1;  
	    $nextPage=($page>=$totalPage)?$totalPage:$page+1;  
	    $prev = ($page == 1) ? "上一页" : "<a href='{$url}?page={$prevPage}'>上一页</a>";  
	    $next = ($page == $totalPage) ? "下一页" : "<a href='{$url}?page={$nextPage}'>下一页</a>";  
	    $str = "总共{$totalPage}页/当前是第{$page}页";  
	    $p="";  
	    for($i = 1; $i <= $totalPage; $i ++) {  
		//当前页无连接  
		if ($page == $i) {  
		    $p .= "[{$i}]";  
		} else {  
		    $p .= "<a href='{$url}?page={$i}'>[{$i}]</a>";  
		}  
	    }  
	    $pageStr=$str.$sep . $index .$sep. $prev.$sep . $p.$sep . $next.$sep . $last;  
	    return $pageStr;  
	}

     function phone_number($mobile){
	$is_good=preg_match("/^1[34578]\d{9}$/", $mobile);
	return $is_good?true:false;
	}