10个开发中常用的PHP代码样例

一、黑名单过滤

    function is_spam($text, $file, $split = ':', $regex = false){
        $handle = fopen($file, 'rb');
        $contents = fread($handle, filesize($file));
        fclose($handle);
        $lines = explode("n", $contents);
    $arr = array();
    foreach($lines as $line){
    list($word, $count) = explode($split, $line);
    if($regex)
    $arr[$word] = $count;
    else
    $arr[preg_quote($word)] = $count;
    }
    preg_match_all("~".implode('|', array_keys($arr))."~", $text, $matches);
    $temp = array();
    foreach($matches[0] as $match){
    if(!in_array($match, $temp)){
    $temp[$match] = $temp[$match] + 1;
    if($temp[$match] >= $arr[$word])
    return true;
    }
    }
    return false;
    } 

    $file = 'spam.txt';
    $str = 'This string has cat, dog word';
    if(is_spam($str, $file))
    echo 'this is spam';
    else
    echo 'this is not spam'; 

    ab:3
    dog:3
    cat:2
    monkey:2 

二、随机颜色生成器

 function randomColor() {
        $str = '#';
        for($i = 0 ; $i < 6 ; $i++) {
            $randNum = rand(0 , 15);
            switch ($randNum) {
                case 10: $randNum = 'A'; break;
                case 11: $randNum = 'B'; break;
                case 12: $randNum = 'C'; break;
                case 13: $randNum = 'D'; break;
                case 14: $randNum = 'E'; break;
                case 15: $randNum = 'F'; break;
            }
            $str .= $randNum;
        }
        return $str;
    }
    $color = randomColor(); 

三、从网上下载文件

    set_time_limit(0);
    // Supports all file types
    // URL Here:
    $url = 'http://somsite.com/some_video.flv';
    $pi = pathinfo($url);
    $ext = $pi['extension'];
    $name = $pi['filename']; 

    // create a new cURL resource
    $ch = curl_init(); 

    // set URL and other appropriate options
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_BINARYTRANSFER, true);
    curl_setopt($ch, CURLOPT_AUTOREFERER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 

    // grab URL and pass it to the browser
    $opt = curl_exec($ch); 

    // close cURL resource, and free up system resources
    curl_close($ch); 

    $saveFile = $name.'.'.$ext;
    if(preg_match("/[^0-9a-z._-]/i", $saveFile))
    $saveFile = md5(microtime(true)).'.'.$ext; 

    $handle = fopen($saveFile, 'wb');
    fwrite($handle, $opt);
    fclose($handle); 

四、Alexa/Google Page Rank

    function page_rank($page, $type = 'alexa'){
    switch($type){
    case 'alexa':
    $url = 'http://alexa.com/siteinfo/';
    $handle = fopen($url.$page, 'r');
    break;
    case 'google':
    $url = 'http://google.com/search?client=navclient-auto&ch=6-1484155081&features=Rank&q=info:';
    $handle = fopen($url.'http://'.$page, 'r');
    break;
    }
    $content = stream_get_contents($handle);
    fclose($handle);
    $content = preg_replace("~(n|t|ss+)~",'', $content);
    switch($type){
    case 'alexa':
    if(preg_match('~<div class="data (down|up)"><img.+?>(.+?) </div>~im',$content,$matches)){
    return $matches[2];
    }else{
    return FALSE;
    }
    break;
    case 'google':
    $rank = explode(':',$content);
    if($rank[2] != '')
    return $rank[2];
    else
    return FALSE;
    break;
    default:
    return FALSE;
    break;
    }
    }
    // Alexa Page Rank:
    echo 'Alexa Rank: '.page_rank('techug.com');
    echo ' ';
    // Google Page Rank
    echo 'Google Rank: '.page_rank('techug.com', 'google'); 

五、强制下载文件

    $filename = $_GET['file']; //Get the fileid from the URL
    // Query the file ID
    $query = sprintf("SELECT * FROM tableName WHERE id = '%s'",mysql_real_escape_string($filename));
    $sql = mysql_query($query);
    if(mysql_num_rows($sql) > 0){
    $row = mysql_fetch_array($sql);
    // Set some headers
    header("Pragma: public");
    header("Expires: 0");
    header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
    header("Content-Type: application/force-download");
    header("Content-Type: application/octet-stream");
    header("Content-Type: application/download");
    header("Content-Disposition: attachment; filename=".basename($row['FileName']).";");
    header("Content-Transfer-Encoding: binary");
    header("Content-Length: ".filesize($row['FileName'])); 

    @readfile($row['FileName']);
    exit(0);
    }else{
    header("Location: /");
    exit;
    } 

六、用Email显示用户的Gravator头像

    $gravatar_link = 'http://www.gravatar.com/avatar/' . md5($comment_author_email) . '?s=32';
    echo '<img src="' . $gravatar_link . '" />'; 

七、用cURL获取RSS订阅数

$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,'https://feedburner.google.com/api/awareness/1.0/GetFeedData?id=7qkrmib4r9rscbplq5qgadiiq4');
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,2);
$content = curl_exec($ch);
$subscribers = get_match('/circulation="(.*)"/isU',$content);
curl_close($ch); 

八、时间差异计算

function ago($time)
{
   $periods = array("second", "minute", "hour", "day", "week", "month", "year", "decade");
$lengths = array("60","60","24","7","4.35","12","10"); 

$now = time(); 

$difference = $now - $time;
$tense = "ago"; 

for($j = 0; $difference >= $lengths[$j] && $j < count($lengths)-1; $j++) {
$difference /= $lengths[$j];
} 

$difference = round($difference); 

if($difference != 1) {
$periods[$j].= "s";
} 

return "$difference $periods[$j] 'ago' ";
} 

九、截取图片

    $filename= "test.jpg";
    list($w, $h, $type, $attr) = getimagesize($filename);
    $src_im = imagecreatefromjpeg($filename); 

    $src_x = '0'; // begin x
    $src_y = '0'; // begin y
    $src_w = '100'; // width
    $src_h = '100'; // height
    $dst_x = '0'; // destination x
    $dst_y = '0'; // destination y 

    $dst_im = imagecreatetruecolor($src_w, $src_h);
    $white = imagecolorallocate($dst_im, 255, 255, 255);
    imagefill($dst_im, 0, 0, $white); 

    imagecopy($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h); 

    header("Content-type: image/png");
    imagepng($dst_im);
    imagedestroy($dst_im); 

十、检查网站是否宕机

    function Visit($url){
           $agent = "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)";$ch=curl_init();
    curl_setopt ($ch, CURLOPT_URL,$url );
    curl_setopt($ch, CURLOPT_USERAGENT, $agent);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt ($ch,CURLOPT_VERBOSE,false);
    curl_setopt($ch, CURLOPT_TIMEOUT, 5);
    curl_setopt($ch,CURLOPT_SSL_VERIFYPEER, FALSE);
    curl_setopt($ch,CURLOPT_SSLVERSION,3);
    curl_setopt($ch,CURLOPT_SSL_VERIFYHOST, FALSE);
    $page=curl_exec($ch);
    //echo curl_error($ch);
    $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);
    if($httpcode>=200 && $httpcode<300) return true;
    else return false;
    }
    if (Visit("http://www.google.com"))
    echo "Website OK"."n";
    else
    echo "Website DOWN";