Tag Archives: PHP

PHP: Get headers with actual HEAD request

PHP has a function called get_headers which, as you’d guess, gives you the headers returned from an HTTP request. However it actually uses a GET, rather than HEAD, request.

Figured out you can change this by setting a stream context, so wrapped it in a function. And posting it here in case I need it again.

Also added a cleanup of the returned array, as I found it a bit ugly when the request included redirects. See difference below code.

Note: I silence the get_headers call because it throws several warnings, e.g. if the hostname fails lookup, and I’m not really interested in why it fails.

function get_head(string $url, array $opts = [])
{
    // Store previous default context
    $prev = stream_context_get_options(stream_context_get_default());

    // Set new one with head and a small timeout
    stream_context_set_default(['http' => $opts +
        [
            'method' => 'HEAD',
            'timeout' => 2,
        ]]);

    // Do the head request
    $req = @get_headers($url, true);
    if( ! $req)
        return false;

    // Make more sane response
    foreach($req as $h => $v)
    {
        if(is_int($h))
            $headers[$h]['Status'] = $v;
        else
        {
            if(is_string($v))
                $headers[0][$h] = $v;
            else
                foreach($v as $x => $y)
                    $headers[$x][$h] = $y;
        }

    }

    // Restore previous default context and return
    stream_context_set_default($prev);
    return $headers;
}

Example response:

<?php get_head('http://geekality.net');

array (size=2)
  0 =>
    array (size=8)
      'Status' => string 'HTTP/1.1 301 Moved Permanently' (length=30)
      'Date' => string 'Mon, 06 Feb 2017 01:20:48 GMT' (length=29)
      'Server' => string 'Apache' (length=6)
      'Location' => string 'http://www.geekality.net/' (length=25)
      'Vary' => string 'Accept-Encoding' (length=15)
      'Connection' => string 'close' (length=5)
      'Content-Type' => string 'text/html; charset=iso-8859-1' (length=29)
      'Link' => string '<http://www.geekality.net/wp-json/>; rel="https://api.w.org/"' (length=61)
  1 =>
    array (size=6)
      'Date' => string 'Mon, 06 Feb 2017 01:20:48 GMT' (length=29)
      'Server' => string 'Apache' (length=6)
      'Vary' => string 'Accept-Encoding' (length=15)
      'Connection' => string 'close' (length=5)
      'Content-Type' => string 'text/html; charset=UTF-8' (length=24)
      'Status' => string 'HTTP/1.1 200 OK' (length=15)

Example response without my cleanup:

<?php get_head('http://geekality.net');

array (size=9)
  0 => string 'HTTP/1.1 301 Moved Permanently' (length=30)
  'Date' =>
    array (size=2)
      0 => string 'Mon, 06 Feb 2017 01:14:00 GMT' (length=29)
      1 => string 'Mon, 06 Feb 2017 01:14:01 GMT' (length=29)
  'Server' =>
    array (size=2)
      0 => string 'Apache' (length=6)
      1 => string 'Apache' (length=6)
  'Location' => string 'http://www.geekality.net/' (length=25)
  'Vary' =>
    array (size=2)
      0 => string 'Accept-Encoding' (length=15)
      1 => string 'Accept-Encoding' (length=15)
  'Connection' =>
    array (size=2)
      0 => string 'close' (length=5)
      1 => string 'close' (length=5)
  'Content-Type' =>
    array (size=2)
      0 => string 'text/html; charset=iso-8859-1' (length=29)
      1 => string 'text/html; charset=UTF-8' (length=24)
  1 => string 'HTTP/1.1 200 OK' (length=15)
  'Link' => string '<http://www.geekality.net/wp-json/>; rel="https://api.w.org/"' (length=61)

PHP: Convert RGB to hex and back

Just another note to self, in case I need it again:

/**
 * #rrggbb or #rgb to [r, g, b]
 */

function hex2rgb(string $hex): array
{
    $hex = ltrim($hex, '#');

    if(strlen($hex) == 3)
        return [
            hexdec($hex[0].$hex[0]),
            hexdec($hex[1].$hex[1]),
            hexdec($hex[2].$hex[2]),
        ];
    else
        return [
            hexdec($hex[0].$hex[1]),
            hexdec($hex[2].$hex[3]),
            hexdec($hex[4].$hex[5]),
        ];
}


/**
 * [r, g, b] to #rrggbb
 */

function rgb2hex(array $rgb): string
{
    return '#'
        . sprintf('%02x', $rgb[0])
        . sprintf('%02x', $rgb[1])
        . sprintf('%02x', $rgb[2]);
}

PHP: Stream a file line-by-line using a generator

This function will “stream” a file line-by-line, as a Generator.

Can be very useful if for example you need to process a big file, don’t want to read the whole thing into memory, but only process each line by itself.

function read($file)
{
    $fp = fopen($file, 'rb');

    while(($line = fgets($fp)) !== false)
        yield rtrim($line, "\r\n");

    fclose($fp);
}

// Usage
foreach(read('http://example.com') as $line)
{
    var_dump($line);
}

PHP: Delete directory recursively

function delete_directory($dir)
{
    if( ! file_exists($dir))
        return;

    $it = new RecursiveDirectoryIterator($dir);
    $it = new RecursiveIteratorIterator($it, RecursiveIteratorIterator::CHILD_FIRST);

    foreach($it as $file)
        if($file->isDir())
            @rmdir($file->getRealPath());
        else
            @unlink($file->getRealPath());
}

PHP test script for cross origin proxy target

Just a script I used as target during some testing of a cross origin proxy to make sure whatever I thought should go through actually went through.

<?php // test.php
$info = [
    'method' => $_SERVER['REQUEST_METHOD'],
    'cookie' => $_COOKIE,
    'get' => $_GET,
    'post' => $_POST,
    'input' => file_get_contents('php://input'),
    'headers' => getallheaders(),
];

ob_start('ob_gzhandler');
header('Content-Type: application/json; charset=utf-8');
header('X-SomeHeader: Some value');
echo json_encode($info, JSON_PRETTY_PRINT | JSON_NUMERIC_CHECK | JSON_FORCE_OBJECT);

PHP: Easy Javascript compression with closure compiler

Here’s how to fairly easily compress/minify Javascript by using the Closure Compiler Service API.

More or less verbatim how I’m currently doing it over at bibelstudiet.no in my script controller class, and so far it’s been working great. Just remember to cache the result on your server so that you’re not calling the API more than necessary. In my case it’s handled further up the chain by the parent class 🙂

<?php
ob_start('ob_gzhandler');
header('Content-Type: text/javascript; charset=utf-8');

$files = ['foo.js', 'bar.js'];

$js = array_map('file_get_contents', $files);
$js = implode(PHP_EOL.PHP_EOL, $script);

$c = curl_init();
curl_setopt_array($ch, array
(
    CURLOPT_URL => 'https://closure-compiler.appspot.com/compile',
    CURLOPT_POST => TRUE,
    CURLOPT_POSTFIELDS => http_build_query([
        'language' => 'ECMASCRIPT5',
        'output_info' => 'compiled_code',
        'output_format' => 'text',
        'compilation_level' => 'SIMPLE_OPTIMIZATIONS',
        'js_code' => $js,
    ]),
));

if(curl_exec($ch) === FALSE)
    http_response_code(500) and exit("// ERROR: ".curl_error($c));

if(curl_getinfo($ch, CURLINFO_CONTENT_LENGTH_DOWNLOAD ) <= 1)
    echo $js;

curl_close($ch);

Note that if the compilation fails for any reason, the response will be empty. In that case I’ve chosen to output the original Javascript instead so the site doesn’t suddenly break. To check what went wrong, you need to repeat the request, but output_info set to errors instead of inline=”true”>compiled_code.

See their API documentation for more information about the parameters.