10个超级有用值得收藏的PHP代码片段
尽管php经常被人诟病,被人贬低,被人当玩笑开,事实证明,php是全世界网站开发中使用率最高的编程语言。php最大的缺点是太简单,语法不严谨,框架体系很弱,但这也是它最大的优点,一个有点编程背景的普通人,只需要学习php半天时间,就可以上手开始开发web应用了。
网上有人总结几种编程语言的特点,我觉得也挺有道理的:
php 就是: quick and dirty
java 就是: beauty and slowly
ruby 就是: quick and beauty
python 就是: quick and simple
在php的流行普及中,网上总结出了很多实用的php代码片段,这些代码片段在当你遇到类似的问题时,粘贴过去就可以使用,非常的高效,非常的省时省力。将这些程序员前辈总结出的优秀代码放到自己的知识库中,是一个善于学习的程序员的好习惯。
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、从网络下载文件
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、通过email显示用户的gravatar头像
$gravatar_link = 'http://www.gravatar.com/avatar/' . md5($comment_author_email) . '?s=32';
echo '<img src="' . $gravatar_link . '" />';
七、通过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($ch);
八、时间差异计算函数
function ago($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、裁剪图片
$filename= "test.jpg";
list($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";