Tag Archives: Computing

Automatically Upload Images with PHP Directly from the URI

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It is a simple task to upload images on the server with PHP using a simple web form. Than everything’s in the $_FILES array and after submitting the form the file’s on the server. By simply move_uploaded_file you can change its location on the server to the desired folder.

However is there a way to “upload” files without using a web form, but only by telling the PHP script where to find the image. First and most important the image should be web visible and accessible by HTTP.

The solution is quite easy – you can grab the file using file_get_contents, and than put it on the desired server folder with file_put_contents. Here’s some source:

$image = file_get_contents('http://www.example.com/image.jpg');
file_put_contents('/var/www/my.jpg', $image);

Extending the Case

You can go even further by downloading any kind of files with the same approach. What will be the case for an mp4 video is shown in the next example:

$video = file_get_contents('http://www.example.com/video.mp4');
file_put_contents('/var/www/my.mp4', $video);

Usage

This can be quite useful when trying to automate an remote upload process. In this case when somebody uploads an image on his site, you can duplicate this file on your server! However don’t forget the copyrights!

HTTP POST with PHP without cURL

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Awesome PHP

a great php idea!
It’s strange how powerful PHP can be. There’s a legend that cURL is the only way to perform a HTTP POST with PHP, but that isn’t the truth. An extremely useful script is by using stream_context_create:

$optional_headers = null;
$params = array('http' => array(
                'method' => 'POST',
                'content' => http_build_query(array('name' => 'my-name'))));
 
if ($optional_headers !== null) {
    $params['http']['header'] = $optional_headers;
}
 
$ctx = stream_context_create($params);
$fp = @fopen('http://example.com/post.php', 'rb', false, $ctx);

Well this is only a snippet. You can change a lot this code and perform any request, but here’s a small start up. However note that this will do the same as while posting to example.com/post.php via web form!

The Better Way to Unset Variables in PHP

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Don’t know why, but most of times I see the PHP unset() multilined with a only one parameter!?

unset($var1);
unset($var2);
unset($var3);

But as you can see from the PHP doc page of unset() this method takes optional parameter count.

void unset(mixed $var [, mixed $var [, mixed $...]])

So perhaps a better solution can be:

unset($var1, $var2, $var3);

It’s at least single lined!

PHP: What is More Powerful Than list() – Perhaps extract()

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list() in PHP

Recently I wrote about list() in PHP which is indeed very powerful when assigning variable values from array elements.

$a = array(10, array('here', 'are', 'some', 'tests'));
list($count, $list) = $a;

Actually my example in the post was not correct, because I wrote that you can pass an associative array, but the truth is that you cannot, and thus the array should be always with numeric keys. After noticing the comments of that post, and thanks to @Philip,  I searched a bit about how this problem can be overcome.

There is a Solution

As always PHP gives a perfect solution! You can see on the list() doc page that there is a function that may help you use an associative array.

Extract

extract() is perhaps less known than list(), but it does the right thing!

$a = array('count' => 10, 'list' => array('here', 'are', 'some', 'tests'));
extract($a);
 
echo $count;    // 10
print_r($list); // array('here'....

Note that now both $count and $list are defined.

PHP: What is More Powerful Than list()

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First of all list() is not an unknown method in the PHP community, where almost every PHP developer knows what it does. The pity is that it has, perhaps, remained useless, although there is hidden power in it!

What is list()?

Let’s assume you’ve two variables and one array with two elements:

$arr = array(1, 2);
$a = $arr[0];
$b = $arr[1];
// now a == 1, and b == 2

Maybe the easiest way to assign to the first variable the value of the first element of the array, and to the second variable the value of the second element of the array is to use list():

list($a, $b) = array(1, 2);
// again a == 1, and b == 2

Note that you can do the same with as many variables/array elements you want.

The funny thing is that nobody use it, while I see at least one perfect usage. You can think of a typical admin panel of any web system. For sure any developer has programmed the typical table page containing a list of “things” and a paging to switch the result set page. It’s like the posts page from the WordPress admin panel, or a search result page in Google, where you’ve one page of results and at the bottom – a number of pages where you can go to another page of the search results.

What I’ve seen in almost every project is that typically the developers prefer to set the results for the page into one list returned from one method and the count of the entire result set is returned by another method.

Thus most of the times there are two methods, performing most commonly a database queries. Something like – getList($offset, $limit) and getCount() where the first one returns the page and the second one returns the count of the result set.

This will result into two methods, two calls and two lines of code:

function getList($offset, $limit)
{
	...
	// although the entire result set contains
	// 5 elements by limiting it from the parameters
	// only three are returned
	return $list; // where $list = array('title1', 'title2', 'title3');	
}
 
function getCount()
{
	...
	// here's returned the count
	// of the entire result set
	return $count; // where $count = 5;	
}
 
$list  = getList(0, 3);
$count = getCount();

What actually you can do is to perform both queries in one method, perhaps called getItems($offset, $limit) where the returned value is an array containing both the list of results and the count:

function getItems($offset, $limit)
{
	...
	return array('list' => $list, 'count' => $count);
}

And finally when calling this method to list() that into the two variables – single lined.

list($list, $count) = getItems(0, 3);