Useful PHP Code Snippets for Common Tasks

PHP is one of the most widely used languages for web development, praised for its simplicity and rapid learning curve. The following collection provides practical PHP code snippets that solve a variety of everyday programming problems.

1. Blacklist Filter

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

2. Random Color Generator

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();

3. Download File from the Internet

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);

4. 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 "\n";
// Google Page Rank
echo 'Google Rank: '.page_rank('techug.com', 'google');

5. Force File Download

$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;
}

6. Display User Gravatar via Email

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

7. Get RSS Subscriber Count via cURL

$ch = curl_init();
curl_setopt($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);

8. Time‑Ago Calculation Function

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' ";
}

9. Image Cropping

$filename= "test.jpg";
list($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);

10. Check if a Website Is Down

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";

This set of snippets can be saved to a personal knowledge base and reused whenever similar requirements arise, helping developers work more efficiently.