Tutorial Generate Expiring Amazon S3 Link

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You don't have to make files on Amazon S3 public (they aren't by default). But you can generate special keys to allow access to private files. These keys are passed through the URL and can be made to expire. 

<?php 

  if(!function_exists('el_crypto_hmacSHA1')){
    /**
    * Calculate the HMAC SHA1 hash of a string.
    *
    * @param string $key The key to hash against
    * @param string $data The data to hash
    * @param int $blocksize Optional blocksize
    * @return string HMAC SHA1
    */
    function el_crypto_hmacSHA1($key, $data, $blocksize = 64) {
        if (strlen($key) > $blocksize) $key = pack('H*', sha1($key));
        $key = str_pad($key, $blocksize, chr(0x00));
        $ipad = str_repeat(chr(0x36), $blocksize);
        $opad = str_repeat(chr(0x5c), $blocksize);
        $hmac = pack( 'H*', sha1(
        ($key ^ $opad) . pack( 'H*', sha1(
          ($key ^ $ipad) . $data
        ))
      ));
        return base64_encode($hmac);
    }
  }

  if(!function_exists('el_s3_getTemporaryLink')){
    /**
    * Create temporary URLs to your protected Amazon S3 files.
    *
    * @param string $accessKey Your Amazon S3 access key
    * @param string $secretKey Your Amazon S3 secret key
    * @param string $bucket The bucket (bucket.s3.amazonaws.com)
    * @param string $path The target file path
    * @param int $expires In minutes
    * @return string Temporary Amazon S3 URL
    * @see http://awsdocs.s3.amazonaws.com/S3/20060301/s3-dg-20060301.pdf
    */
    
    function el_s3_getTemporaryLink($accessKey, $secretKey, $bucket, $path, $expires = 5) {
      // Calculate expiry time
      $expires = time() + intval(floatval($expires) * 60);
      // Fix the path; encode and sanitize
      $path = str_replace('%2F', '/', rawurlencode($path = ltrim($path, '/')));
      // Path for signature starts with the bucket
      $signpath = '/'. $bucket .'/'. $path;
      // S3 friendly string to sign
      $signsz = implode("\n", $pieces = array('GET', null, null, $expires, $signpath));
      // Calculate the hash
      $signature = el_crypto_hmacSHA1($secretKey, $signsz);
      // Glue the URL ...
      $url = sprintf('http://%s.s3.amazonaws.com/%s', $bucket, $path);
      // ... to the query string ...
      $qs = http_build_query($pieces = array(
        'AWSAccessKeyId' => $accessKey,
        'Expires' => $expires,
        'Signature' => $signature,
      ));
      // ... and return the URL!
      return $url.'?'.$qs;
    }
  }

?>

Usage

<?php echo el_s3_getTemporaryLink('your-access-key', 'your-secret-key', 'bucket-name', '/path/to/file.mov'); ?>

Reference URL

Tutorial Generate CSV from Array

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function generateCsv($data, $delimiter = ',', $enclosure = '"') {
       $handle = fopen('php://temp', 'r+');
       foreach ($data as $line) {
               fputcsv($handle, $line, $delimiter, $enclosure);
       }
       rewind($handle);
       while (!feof($handle)) {
               $contents .= fread($handle, 8192);
       }
       fclose($handle);
       return $contents;
}

Usage

$data = array(
       array(1, 2, 4),
       array('test string', 'test, literal, comma', 'test literal "quotes"'),
);

echo generateCsv($data);
// outputs:
// 1,2,4
// "test string","test, literal, comma","test literal""quote"""

Tutorial Force Leading Zero

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<?php
  function forceLeadingZero($int) {
    return (int)sprintf('%02d',$int);
  }
?>

Forces leading zero to integers.

was | now

1 | 01
2 | 02
3 | 03

10 | 10
100 | 100
99 | 99

Reference URL

Tutorial Find URLs in Text, Make Links

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<?php

// The Regular Expression filter
$reg_exUrl = "/(http|https|ftp|ftps)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/";

// The Text you want to filter for urls
$text = "The text you want to filter goes here. http://google.com";

// Check if there is a url in the text
if(preg_match($reg_exUrl, $text, $url)) {

       // make the urls hyper links
       echo preg_replace($reg_exUrl, "<a href="{$url[0]}">{$url[0]}</a> ", $text);

} else {

       // if no urls in the text just return the text
       echo $text;

}
?>

The basic function of this is to find any URLs in the block of text and turn them into hyperlinks. It will only find URLs if they are properly formatted, meaning they have a http, https, ftp or ftps.

Check out the comments below for more solutions.

PHP Define Full Path to a File

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<?php
  echo dirname(__FILE__);
?>
Save the file as fullpath.php Upload to the folder you'd like to know the full path to Go to http://www.yoursite/lots/of/folders/fullpath.php

You'd might be surprised what shows up. Sometimes you need more than just /lots/of/folders/ as your full path to a file (e.g. .htpasswd). This script will allow you to see that.

Tutorial Find Highest Numerically Named File

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$latest = getNewest("/path/to/folder/*_bla.xml");

function getNewest($xmlfile){
   foreach (glob($xmlfile) as $filename) {
       $c = explode('_', basename($filename));
       $files[$c[0]] = $filename;
   }
   ksort($files, SORT_NUMERIC);
   $latest = array_pop($files);
   if (file_exists($latest)){
       return $latest;
   }
   return false;
}

In a folder are files named:
1_bla.xml
2_bla.xml
...
34_bla.xml

The function returns the file with the biggest numeric number:
$latest = "/path/to/folder/34_bla.xml";

Tutorial Find File Extension

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Method 1

function findexts ($filename) {

       $filename = strtolower($filename) ;

       $exts = split("[/\\.]", $filename) ;

       $n = count($exts)-1;

       $exts = $exts[$n];

       return $exts;

}

Method 2

$filename = 'mypic.gif';
$ext = pathinfo($filename, PATHINFO_EXTENSION);

Method 3

function getFileextension($file) {
       return end(explode(".", $file));
}