Images and PHP

[The Numerator]

I have a folder full with images, and for security reasons I don't want
anyone to know where the folder is. So, to call images, I know there is
a way to call like a PHP file instead. For example Galley 2 (a
PHP-enabled photo album) safetly tucks away the actual images and in
the image source, it calls for something like
"main.php?g2_view=core.DownloadItem&g2_itemId=12&g2_serialNumber=3".

How do you do that? Do you need to use the database to do this? Thank
you.

[The Numerator]

I forgot to say something: Is there any way to do something like this:

<img src="http://www.example.com/image.php?image=car">

[Darkstar 3D]

Yes! If it is a lot of images, I normally store them in a db and call
them as needed with a script that takes that car and brings me back the
image indexed to car.

[fletch]

Let's think about why you don't want people to know where the folder is
for a second. Presumably this is because you don't want all the images
downloaded by guessing the url. Therefore sticking itemid in the url
makes an equivelence.

If you are having your images uploaded then it would be a simple job to
store the ddetails of the image in a db and call them out when
required.

You could have an image 1.gif and give it the url
/img/{filecode}.gif/as/1.gif

where {filecode} is some random number, perhaps even
itemid-filecode.gif.

Then in the webroot you have a directory called img in which you put a
.htaccess file containing

RewriteEngine On
RewriteBase /img
RewriteRule ^(.*)(/as/)(.*)$ /images/$1
Options -Indexes

The file is then save to /images/{filecode}.gif

The random number prevents easy guessing of image names and the
structure of the url makes the browser theink the file is called 1.gif.

This presumably covers your requirements and means that apache does all
the work without having to use PHP to get the file, which is much more
efficient. Also since the OS is being asked for a file then it's file
caching functions swing in to force meaning the most common images are
likely to be stored in RAM for even quicker delivery.

[Good Man]

"The Numerator" <alvin...@gmail.com> wrote in
news:1145849539....@t31g2000cwb.googlegroups.com:

yes, use a database, but not to store images in.

put the images in a folder above the web root. that way, the images
simply cannot be accessed via the web, period.

in the database, store the image name, the path to the image (from the
SERVER's point of view, not a web address, since there is no web address
that can access the image), and a 'keystring', generated by you/your app,
that uniquely identifies the database entry. For example, the keystring
for image 1 could be 'asdiuhsadha1312' and for image 2, it could be
'fjgkjdfgudsagh'.

to retrieve, or link to the image on a webpage, you could call the file
"fetchphoto.php" like so:
<a href="fetchphoto.php?vKeystring=asdiuhsadha1312">Fetch this photo!</a>

your 'fetchphoto.php' page then looks up the server path to the image in
the database (according to the keystring), and uses fopen() and fread()
to deliver the image to the web browser.

this method is infinitely easier than the others suggested IMHO.

ps: the reason you use a 'keystring' and not just an ID from the database
is to prevent people from changing "fetchphoto.php?vID=1" to
"fetchphoto.php?vID=2" and download other photos that they shoudn't.

good luck.

[robert]

"The Numerator" <alvin...@gmail.com> wrote in message
news:1145849539....@t31g2000cwb.googlegroups.com...

i don't normally do this, but i'm going to paste source. (sorry about the
text wrapping). do NOT store images in a db as this limits your options when
you consider migrating from one db to another and the amount of code that
could need changes. it's a pain in the ass. the following requires the gdi
lib. anyway, here's how to call this first set of code (generates a
thumbnail of an image and when clicked, opens the actual file):

note that i include a config page with a "site" class that stores info about
the web site...$site->uri would be like "http://www.mysite.org/"...you'll
notice other functions that come from my functions.inc.php script...just
modify what you need to - even hard code for now.

<a
href="<?= $site->uri ?>get.file.php?fileName=blah.jpg"
style="font-size:8pt;"
target="VIEW_FILE"
>
<img
src="<?= $site->uri ?>get.thumb.nail.php?fileName=blah.jpg&maxSize=200"
alt="File Not Found!"
title="Click To Open: blah.jpg"
/>
blah.jpg
</a>

====== contents of get.thumb.nail.php ========

<?
require_once 'site.cfg.php';
require_once $site->includeDirectory . 'functions.inc.php';
$fileName = $_REQUEST['fileName'] ? $_REQUEST['fileName'] :
$_REQUEST['altImage'];
$maxSize = $_REQUEST['maxSize'] ? $_REQUEST['maxSize'] : 200;
$filePath = $site->imagesDirectory;
if (!(isSupportedImage($fileName) || isSupportedMedia($fileName)))
{
$fileName = isSupportedMedia($fileName) ? 'media.jpg' :
'document.jpg';
}
$fileData = @file_get_contents($filePath . $fileName);
$originalImage = @imagecreatefromstring($fileData);
@list($imageWidth, $imageHeight, $imageType, $imageAttributes) =
@getimagesize($filePath . $fileName);
$newImageHeight = $imageWidth < $maxSize ? $imageHeight : ($imageHeight /
$imageWidth) * $maxSize;
$newImageWidth = $imageWidth < $maxSize ? $imageWidth : $maxSize;
$thumbNail = @imagecreatetruecolor($newImageWidth, $newImageHeight);
@imagecopyresampled(
$thumbNail,
$originalImage,
0,
0,
0,
0,
$newImageWidth,
$newImageHeight,
@imagesx($originalImage),
@imagesy($originalImage)
);
@imagejpeg($thumbNail);
@imagedestroy($thumbNail);
@imagedestroy($originalImage);
?>

===========

======= contents of get.file.php ==========

<?
require_once 'site.cfg.php';
$fileData = '';
$fileName = $_REQUEST['fileName'];
$filePath = $site->uploadBaseDirectory;
if ($fileName != ''){ $fileData = @file_get_contents($filePath .
$fileName); }
header("content-type: application/octet-stream" );
header("content-size: " . count($fileData) );
header("content-disposition: inline; filename=$fileName");
echo $fileData;
?>

===========

hth,

me

[robert]

| This presumably covers your requirements and means that apache does all
| the work without having to use PHP to get the file, which is much more
| efficient. Also since the OS is being asked for a file then it's file
| caching functions swing in to force meaning the most common images are
| likely to be stored in RAM for even quicker delivery.

not to split hairs...but...

this dedicates you to only using apache as the web server and relies on
everyone having a list of detailed instructions (like you just gave) in
order to deploy the solution. not only that, but some people have web
hosting services that are pricks and won't allow you to do that.

and from all the hub-bub about using keys...it may as well *be* a file name.
one has an equal chance at guessing the next key as to guessing the correct
name of another image. further, in the method above, there is no graceful
way to display that the image was not found...apache simply either coughs up
a nasty error or your image's alt text will be all that's shown.

also, there is no real need to hit the db to see if the image exists. if you
need to display the details related to the image, that's another story.

finally, whether an image is cached in ram or read from disk is a non-issue.
that will never compare to the time lost during transport - especially for
larger images. the difference in times in preparing the image for transport
is nano-seconds at best.

i've said all that to raise valid considerations to the described
approach...not to knock the idea. if you program it correctly in php, you
can put the code on any server, any os, and never have to configure a thing
except the rights on the folder containing the images/files.

just a thought.