PHP实用代码片段（四）

1. 删除文件夹内容

function Delete($path)
{
    if (is_dir($path) === true)
    {
        $files = array_diff(scandir($path), array('.', '..'));
        foreach ($files as $file)
        {
            Delete(realpath($path) . '/' . $file);
        }
        return rmdir($path);
    }
    else if (is_file($path) === true)
    {
        return unlink($path);
    }
    return false;
}

语法：

<?php
$path = "images/";
Delete($path); // This will delete images folder along with its contents.
?>

2. 搜索和高亮字符串中的关键字

function highlighter_text($text, $words)
{
    $split_words = explode( " " , $words );
    foreach($split_words as $word)
    {
        $color = "#4285F4";
        $text = preg_replace("|($word)|Ui" ,
            "<span style="color:".$color.";"><b>$1</b></span>" , $text );
    }
    return $text;
}

语法：

<?php
$string = "I like chocolates and I like apples";
$words = "apple";
echo highlighter_text($string ,$words);
?>

3. 写入文件

<?
$filename = 'blog.csv';
$fp = fopen($filename, 'w');
$output = " Hello ";
$output .= " World! ";
$output .= "
";
fputs($fp, $output);
fclose($fp);
?>

4. 根据 URL 下载图片

function imagefromURL($image,$rename)
{
$ch = curl_init($image);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_BINARYTRANSFER,1);
$rawdata=curl_exec ($ch);
curl_close ($ch);
$fp = fopen("$rename",'w');
fwrite($fp, $rawdata); 
fclose($fp);
}

语法：

<?php
$url = "http://koonk.com/images/logo.png";
$rename = "koonk.png";
imagefromURL($url,$rename);
?>

5. 检测 URL 是否有效

function isvalidURL($url)
{
$check = 0;
if (filter_var($url, FILTER_VALIDATE_URL) !== false) {
  $check = 1;
}
return $check;
}

语法：

<?php
$url = "http://koonk.com";
$check = checkvalidURL($url);
echo $check; //if returns 1 then URL is valid.
?>

6. 生成二维码

function qr_code($data, $type = "TXT", $size ='150', $ec='L', $margin='0')  
{
     $types = array("URL" =--> "http://", "TEL" => "TEL:", "TXT"=>"", "EMAIL" => "MAILTO:");
    if(!in_array($type,array("URL", "TEL", "TXT", "EMAIL")))
    {
        $type = "TXT";
    }
    if (!preg_match('/^'.$types[$type].'/', $data))
    {
        $data = str_replace("\", "", $types[$type]).$data;
    }
    $ch = curl_init();
    $data = urlencode($data);
    curl_setopt($ch, CURLOPT_URL, 'http://chart.apis.google.com/chart');
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, 'chs='.$size.'x'.$size.'&cht=qr&chld='.$ec.'|'.$margin.'&chl='.$data);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_TIMEOUT, 30);
    $response = curl_exec($ch);
    curl_close($ch);
    return $response;
}

语法：

<?php
header("Content-type: image/png");
echo qr_code("http://koonk.com", "URL");
?>

7. 计算两个地图坐标之间的距离

function getDistanceBetweenPointsNew($latitude1, $longitude1, $latitude2, $longitude2) {
    $theta = $longitude1 - $longitude2;
    $miles = (sin(deg2rad($latitude1)) * sin(deg2rad($latitude2))) + (cos(deg2rad($latitude1)) * cos(deg2rad($latitude2)) * cos(deg2rad($theta)));
    $miles = acos($miles);
    $miles = rad2deg($miles);
    $miles = $miles * 60 * 1.1515;
    $feet = $miles * 5280;
    $yards = $feet / 3;
    $kilometers = $miles * 1.609344;
    $meters = $kilometers * 1000;
    return compact('miles','feet','yards','kilometers','meters'); 
}

语法：

<?php
$point1 = array('lat' => 40.770623, 'long' => -73.964367);
$point2 = array('lat' => 40.758224, 'long' => -73.917404);
$distance = getDistanceBetweenPointsNew($point1['lat'], $point1['long'], $point2['lat'], $point2['long']);
foreach ($distance as $unit => $value) {
    echo $unit.': '.number_format($value,4).'<br />';
}
?>

8. 获取一个特定话题标签的所有 Tweets

function getTweets($hash_tag) {
    $url = 'http://search.twitter.com/search.atom?q='.urlencode($hash_tag) ;
    echo "<p>Connecting to <strong>$url</strong> ...</p>";
    $ch = curl_init($url);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, TRUE);
    $xml = curl_exec ($ch);
    curl_close ($ch);
    //If you want to see the response from Twitter, uncomment this next part out:
    //echo "<p>Response:</p>";
    //echo "<pre>".htmlspecialchars($xml)."</pre>";
    $affected = 0;
    $twelement = new SimpleXMLElement($xml);
    foreach ($twelement->entry as $entry) {
        $text = trim($entry->title);
        $author = trim($entry->author->name);
        $time = strtotime($entry->published);
        $id = $entry->id;
        echo "<p>Tweet from ".$author.": <strong>".$text."</strong>  <em>Posted ".date('n/j/y g:i a',$time)."</em></p>";
    }
    return true ;
}

9. 添加 th,st,nd 或者 rd 作为数字的后缀

function ordinal($cdnl){ 
    $test_c = abs($cdnl) % 10; 
    $ext = ((abs($cdnl) %100 < 21 && abs($cdnl) %100 > 4) ? 'th' 
            : (($test_c < 4) ? ($test_c < 3) ? ($test_c < 2) ? ($test_c < 1) 
            ? 'th' : 'st' : 'nd' : 'rd' : 'th')); 
    return $cdnl.$ext; 
}

语法：

<?php
$number = 10;
echo ordinal($number); //output is 10th
?>

10. 限制文件下载的速度

<?php
// local file that should be send to the client
$local_file = 'test-file.zip';
// filename that the user gets as default
$download_file = 'your-download-name.zip';
 
// set the download rate limit (=> 20,5 kb/s)
$download_rate = 20.5; 
if(file_exists($local_file) && is_file($local_file)) {
    // send headers
    header('Cache-control: private');
    header('Content-Type: application/octet-stream'); 
    header('Content-Length: '.filesize($local_file));
    header('Content-Disposition: filename='.$download_file);
 
    // flush content
    flush();    
    // open file stream
    $file = fopen($local_file, "r");    
    while(!feof($file)) {
 
        // send the current file part to the browser
        print fread($file, round($download_rate * 1024));    
 
        // flush the content to the browser
        flush();
 
        // sleep one second
        sleep(1);    
    }    
 
    // close file stream
    fclose($file);}
else {
    die('Error: The file '.$local_file.' does not exist!');
}
?>

11. 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);
?>

12. 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;
?>

13. 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.<br />".$output;
?>

14. 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;
?>

15. youtube 下载链接生成器

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=$t_id&fmt=17";
    echo "		Download (right-click > save as):
		";
    echo "<a href="$flv_link">FLV</a>
		";
    echo "<a href="$hq_flv_link">HQ FLV (if available)</a>
		";
    echo "<a href="$mp4_link">MP4</a>
		";
    echo "<a href="$threegp_link">3GP</a><br><br>
";
}

16. 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
?>