Six ultra-practical PHP code snippets _ php instances

This article mainly introduces 10 super practical PHP code samples: Blacklist filtering, random color generator, download files from the Internet, force download files, screenshot pictures, and check whether the website is down, for more information, see I. 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 

Ii. 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 files 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. 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; } 

5. screenshot

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

6. 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"; 

The above are six examples of super practical PHP code. I hope it will help you learn PHP programming.