10 super useful PHP code snippets (recommended collection)

This article mainly introduces 10 super useful PHP code snippets worth collecting. This article explains blacklist filtering, random color generator, downloading files from the network, forced downloading of files, displaying the user's Gravatar avatar through Email, etc., you need Friends can refer to it.

Although PHP is often criticized, belittled, and treated as a joke, it turns out that PHP is the most used programming language in website development in the world. The biggest disadvantage of PHP is that it is too simple, the syntax is not rigorous, and the framework system is very weak, but this is also its biggest advantage. An ordinary person with a programming background only needs to learn PHP for half a day to start developing web applications.

Some people on the Internet have summarized the characteristics of several programming languages, which I think makes sense:

PHP 就是： Quick and Dirty

Java 就是： Beauty and Slowly

Ruby 就是： Quick and Beauty

python 就是： Quick and Simple

With the popularity of PHP, many practical PHP code snippets have been summarized on the Internet. These When you encounter similar problems, you can paste the code snippet and use it. It is very efficient and saves time and effort. Putting the excellent codes summarized by these senior programmers into your own knowledge base is a good habit of a programmer who is good at learning.

1. Blacklist filtering

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 = &#39;A&#39;; break; 
            case 11: $randNum = &#39;B&#39;; break; 
            case 12: $randNum = &#39;C&#39;; break; 
            case 13: $randNum = &#39;D&#39;; break; 
            case 14: $randNum = &#39;E&#39;; break; 
            case 15: $randNum = &#39;F&#39;; break; 
        } 
        $str .= $randNum; 
    } 
    return $str; 
} 
$color = randomColor();

3. From the network Download file

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(&#39;~<p class="data (down|up)"><img.+?>(.+?) </p>~im&#39;,$content,$matches)){ 
                return $matches[2]; 
            }else{ 
                return FALSE; 
            } 
        break; 
        case &#39;google&#39;: 
            $rank = explode(&#39;:&#39;,$content); 
            if($rank[2] != &#39;&#39;) 
                return $rank[2]; 
            else 
                return FALSE; 
        break; 
        default: 
            return FALSE; 
        break; 
    } 
} 
// Alexa Page Rank: 
echo &#39;Alexa Rank: &#39;.page_rank(&#39;techug.com&#39;); 
echo &#39;
&#39;; 
// Google Page Rank 
echo &#39;Google Rank: &#39;.page_rank(&#39;techug.com&#39;, &#39;google&#39;);

5. Force download file

$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 the user’s Gravatar avatar through Email

$gravatar_link = 'http://www.gravatar.com/avatar/' . md5($comment_author_email) . '?s=32';
  echo &#39;<img src="&#39; . $gravatar_link . &#39;" />&#39;;

7. Obtain the number of RSS subscriptions through 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 difference 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] &#39;ago&#39; ";
}

9. Crop the picture

$filename= "test.jpg";
list($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 whether the 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";

Recommended learning: php video tutorial

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