56个 PHP 开发常用代码片段（下）
41. 把文本转换成图片
<?php
header("Content-type: image/png");
$string = $_GET['text'];
$im = imagecreatefrompng("images/button.png");
$color = imagecolorallocate($im, 255, 255, 255);
$px = (imagesx($im) - 7.5 * strlen($string)) / 2;
$py = 9;
$fontSize = 1;
imagestring($im, fontSize, $px, $py, $string, $color);
imagepng($im);
imagedestroy($im);
?>42. 获取远程文件的大小
function remote_filesize($url, $user = "", $pw = "")
{
ob_start();
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_NOBODY, 1);
if(!empty($user) && !empty($pw))
{
$headers = array('Authorization: Basic ' . base64_encode("$user:$pw"));
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
}
$ok = curl_exec($ch);
curl_close($ch);
$head = ob_get_contents();
ob_end_clean();
$regex = '/Content-Length:\s([0-9].+?)\s/';
$count = preg_match($regex, $head, $matches);
return isset($matches[1]) ? $matches[1] : "unknown";
}语法：
<?php
$file = "http://koonk.com/images/logo.png";
$size = remote_filesize($url);
echo $size;
?>43. 使用 imagebrick 进行 pdf 到图像的转换
<?php
$pdf_file = './pdf/demo.pdf';
$save_to = './jpg/demo.jpg'; //make sure that apache has permissions to write in this folder! (common problem)
//execute ImageMagick command 'convert' and convert PDF to JPG with applied settings
exec('convert "'.$pdf_file.'" -colorspace RGB -resize 800 "'.$save_to.'"', $output, $return_var);
if($return_var == 0) { //if exec successfuly converted pdf to jpg
print "Conversion OK";
}
else print "Conversion failed.".$output;
?>44. 使用 tinyurl 生成短网址
function get_tiny_url($url)
{
$ch = curl_init();
$timeout = 5;
curl_setopt($ch,CURLOPT_URL,'http://tinyurl.com/api-create.php?url='.$url);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,$timeout);
$data = curl_exec($ch);
curl_close($ch);
return $data;
}语法：
<?php
$url = "http://blog.koonk.com/2015/07/Hello-World";
$tinyurl = get_tiny_url($url);
echo $tinyurl;
?>45. youtube 下载链接生成器
使用下面的 PHP 片段可以让你的用户下载 Youtube 视频
function str_between($string, $start, $end)
{
$string = " ".$string; $ini = strpos($string,$start); if ($ini == 0) return ""; $ini += strlen($start); $len = strpos($string,$end,$ini) - $ini; return substr($string,$ini,$len); }
function get_youtube_download_link(){
$youtube_link = $_GET['youtube'];
$youtube_page = file_get_contents($youtube_link);
$v_id = str_between($youtube_page, "&video_id=", "&");
$t_id = str_between($youtube_page, "&t=", "&");
$flv_link = "http://www.youtube.com/get_video?video_id=$v_id&t=$t_id";
$hq_flv_link = "http://www.youtube.com/get_video?video_id=$v_id&t=$t_id&fmt=6";
$mp4_link = "http://www.youtube.com/get_video?video_id=$v_id&t=$t_id&fmt=18";
$threegp_link = "http://www.youtube.com/get_video?video_id=$v_id&t=$t_id&fmt=17";
echo "\t\tDownload (right-click > save as):\n\t\t";
echo "<a href=\"$flv_link\">FLV</a>\n\t\t";
echo "<a href=\"$hq_flv_link\">HQ FLV (if available)</a>\n\t\t";
echo "<a href=\"$mp4_link\">MP4</a>\n\t\t";
echo "<a href=\"$threegp_link\">3GP</a>\n";
}46. Facebook 样式的时间戳
Facebook (x mins age, y hours ago etc)
function nicetime($date)
{
if(empty($date)) {
return "No date provided";
}
$periods = array("second", "minute", "hour", "day", "week", "month", "year", "decade");
$lengths = array("60","60","24","7","4.35","12","10");
$now = time();
$unix_date = strtotime($date);
// check validity of date
if(empty($unix_date)) {
return "Bad date";
}
// is it future date or past date
if($now > $unix_date) {
$difference = $now - $unix_date;
$tense = "ago";
} else {
$difference = $unix_date - $now;
$tense = "from now";
}
for($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] {$tense}";
}语法：
<?php
$date = "2015-07-05 03:45";
$result = nicetime($date); // 2 days ago
?>47、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';输出：
ab:3
dog:3
cat:2
monkey:248、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();49、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);50、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');51、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;
}52、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 '<lt;img src="' . $gravatar_link . '" />';53、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($ch);54、时间差异计算函数
function ago($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' ";
}55、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($dst_im);56、检查网站是否宕机
function Visit($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";