function encryptDecrypt($key, $string, $decrypt){ 
    if($decrypt){ 
        $decrypted = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, md5(md5($key))), "12"); 
        return $decrypted; 
    }else{ 
        $encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, md5(md5($key)))); 
        return $encrypted; 
    } 
}

//以下是將字符串“Helloweba歡迎您”分別加密和解密 
//加密： 
echo encryptDecrypt('password', 'Helloweba歡迎您',0); 
//解密： 
echo encryptDecrypt('password', 'z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk=',1);

function generateRandomString($length = 10) { 
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; 
    $randomString = ''; 
    for ($i = 0; $i < $length; $i++) { 
        $randomString .= $characters[rand(0, strlen($characters) - 1)]; 
    } 
    return $randomString; 
}

echo generateRandomString(20);

function getExtension($filename){ 
  $myext = substr($filename, strrpos($filename, '.')); 
  return str_replace('.','',$myext); 
}

$filename = '我的文檔.doc'; 
echo getExtension($filename);

function formatSize($size) { 
    $sizes = array(" Bytes", " KB", " MB", " GB", " TB", " PB", " EB", " ZB", " YB"); 
    if ($size == 0) {  
        return('n/a');  
    } else { 
      return (round($size/pow(1024, ($i = floor(log($size, 1024)))), 2) . $sizes[$i]);  
    } 
}

$thefile = filesize('test_file.mp3'); 
echo formatSize($thefile);

function stringParser($string,$replacer){ 
    $result = str_replace(array_keys($replacer), array_values($replacer),$string); 
    return $result; 
}

$string = 'The anchor text{/b} is the actual word{/b} or words used {br}to describe the link {br}itself'; 
$replace_array = array('' => '<b>','{/b}' => '</b>','{br}' => '<br />'); 
 
echo stringParser($string,$replace_array);

function listDirFiles($DirPath){ 
    if($dir = opendir($DirPath)){ 
         while(($file = readdir($dir))!== false){ 
                if(!is_dir($DirPath.$file)) 
                { 
                    echo "filename: $file<br />"; 
                } 
         } 
    } 
}

listDirFiles('home/some_folder/');

function curPageURL() { 
    $pageURL = 'http'; 
    if (!empty($_SERVER['HTTPS'])) {$pageURL .= "s";} 
    $pageURL .= "://"; 
    if ($_SERVER["SERVER_PORT"] != "80") { 
        $pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"]; 
    } else { 
        $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"]; 
    } 
    return $pageURL; 
}

echo curPageURL();

function download($filename){ 
    if ((isset($filename))&&(file_exists($filename))){ 
       header("Content-length: ".filesize($filename)); 
       header('Content-Type: application/octet-stream'); 
       header('Content-Disposition: attachment; filename="' . $filename . '"'); 
       readfile("$filename"); 
    } else { 
       echo "Looks like file does not exist!"; 
    } 
}

download('/down/test_45f73e852.zip');

/* 
 Utf-8、gb2312都支持的漢字截取函數(shù) 
 cut_str(字符串, 截取長(zhǎng)度, 開(kāi)始長(zhǎng)度, 編碼); 
 編碼默認(rèn)為 utf-8 
 開(kāi)始長(zhǎng)度默認(rèn)為 0 
*/ 
function cutStr($string, $sublen, $start = 0, $code = 'UTF-8'){ 
    if($code == 'UTF-8'){ 
        $pa = "/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/"; 
        preg_match_all($pa, $string, $t_string); 
 
        if(count($t_string[0]) - $start > $sublen) return join('', array_slice($t_string[0], $start, $sublen))."..."; 
        return join('', array_slice($t_string[0], $start, $sublen)); 
    }else{ 
        $start = $start*2; 
        $sublen = $sublen*2; 
        $strlen = strlen($string); 
        $tmpstr = ''; 
 
        for($i=0; $i<$strlen; $i++){ 
            if($i>=$start && $i<($start+$sublen)){ 
                if(ord(substr($string, $i, 1))>129){ 
                    $tmpstr.= substr($string, $i, 2); 
                }else{ 
                    $tmpstr.= substr($string, $i, 1); 
                } 
            } 
            if(ord(substr($string, $i, 1))>129) $i++; 
        } 
        if(strlen($tmpstr)<$strlen ) $tmpstr.= "..."; 
        return $tmpstr; 
    } 
}

$str = "jQuery插件實(shí)現(xiàn)的加載圖片和頁(yè)面效果"; 
echo cutStr($str,16);

//獲取用戶真實(shí)IP 
function getIp() { 
    if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown")) 
        $ip = getenv("HTTP_CLIENT_IP"); 
    else 
        if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown")) 
            $ip = getenv("HTTP_X_FORWARDED_FOR"); 
        else 
            if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown")) 
                $ip = getenv("REMOTE_ADDR"); 
            else 
                if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown")) 
                    $ip = $_SERVER['REMOTE_ADDR']; 
                else 
                    $ip = "unknown"; 
    return ($ip); 
}

echo getIp();

function injCheck($sql_str) {  
    $check = preg_match('/select|insert|update|delete|'|/*|*|../|./|union|into|load_file|outfile/', $sql_str);
    if ($check) { 
        echo '非法字符！！'; 
        exit; 
    } else { 
        return $sql_str; 
    } 
}

echo injCheck('1 or 1=1');

function message($msgTitle,$message,$jumpUrl){ 
    $str = '<!DOCTYPE HTML>'; 
    $str .= '<html>'; 
    $str .= '<head>'; 
    $str .= '<meta charset="utf-8">'; 
    $str .= '<title>頁(yè)面提示</title>'; 
    $str .= '<style type="text/css">'; 
    $str .= '*{margin:0; padding:0}a{color:#369; text-decoration:none;}a:hover{text-decoration:underline}body{height:100%; font:12px/18px Tahoma, Arial,  sans-serif; color:#424242; background:#fff}.message{width:450px; height:120px; margin:16% auto; border:1px solid #99b1c4; background:#ecf7fb}.message h3{height:28px; line-height:28px; background:#2c91c6; text-align:center; color:#fff; font-size:14px}.msg_txt{padding:10px; margin-top:8px}.msg_txt h4{line-height:26px; font-size:14px}.msg_txt h4.red{color:#f30}.msg_txt p{line-height:22px}'; 
    $str .= '</style>'; 
    $str .= '</head>'; 
    $str .= '<body>'; 
    $str .= '<div class="message">'; 
    $str .= '<h3>'.$msgTitle.'</h3>'; 
    $str .= '<div class="msg_txt">'; 
    $str .= '<h4 class="red">'.$message.'</h4>'; 
    $str .= '<p>系統(tǒng)將在 <span style="color:blue;font-weight:bold">3</span> 秒后自動(dòng)跳轉(zhuǎn),如果不想等待,直接點(diǎn)擊 <a href="{$jumpUrl}">這里</a> 跳轉(zhuǎn)</p>'; 
    $str .= "<script>setTimeout('location.replace('".$jumpUrl."')',2000)</script>"; 
    $str .= '</div>'; 
    $str .= '</div>'; 
    $str .= '</body>'; 
    $str .= '</html>'; 
    echo $str; 
}

message('操作提示','操作成功！','http://m.survivalescaperooms.com/');

function changeTimeType($seconds) { 
    if ($seconds > 3600) { 
        $hours = intval($seconds / 3600); 
        $minutes = $seconds % 3600; 
        $time = $hours . ":" . gmstrftime('%M:%S', $minutes); 
    } else { 
        $time = gmstrftime('%H:%M:%S', $seconds); 
    } 
    return $time; 
}

$seconds = 3712; 
echo changeTimeType($seconds);