PHP编程：6个超实用的PHP代码片段

《6个超实用的PHP代码片段》要点：
本文介绍了6个超实用的PHP代码片段，希望对您有用。如果有疑问，可以联系我们。

PHP学习一、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,CURLOPT_FOLLOWLOCATION,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、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; 
} 

五、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); 
imagefill($dst_im,$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); 

六、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 ($ch,$url ); 
curl_setopt($ch,CURLOPT_USERAGENT,$agent); 
curl_setopt ($ch,1); 
curl_setopt ($ch,CURLOPT_VERBOSE,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"; 

以上就是6个超实用的PHP代码样例,希望对大家学习PHP编程有所赞助,果断收藏吧

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