Image upload

phpnewbi

I have a classified ad script and when someone posts an ad, they can upload an image. If they do upload an image, the file name of the image is what ever they entered in the subject... for example:

Subject: This is the subject
Image File: This is the subject.gif

How can I get it so the Image File is random numbers/letters and not the subject line? Here's the upload code:

if(is_array($image))

	{

		$filext = explode(".",$image['name']);

		$filext = $filext[(count($filext)-1)];



		echo $image['name'] . '<br>';



		move_uploaded_file($image['tmp_name'], AD_IMAGES.addslashes($title).'.'.$filext);

		$image_url = SERVER_ROOT.AD_IMAGES.addslashes($title).'.'.$filext;

	}

Any help is appreciated! 🙂

jkurrle

Well, one way you could generate a so-called random number is to set it to the time it was uploaded, aka, the time() function.

time() generates the number of seconds from January 1st, 1970, which would pretty much guarantee a unique number for each upload. You could always put in a checking mechanism, just to be safe in case of two people uploading files in the same exact second.

Assuming the variable name assigned to the upload file is "Upload_File" and that the path/filename of the new file is $target_file, you could try the following statement to rename the file as you move it:

move_uploaded_file($_FILES['Upload_File']['tmp_name'], $target_file);

Hope this helps...

sid

[man]microtime/man would produce an even more "random" value.

there are many ways to accomplish this task. if its about "randomness" and your intention is that filenames can't be easily guessed, you could use [man]md5/man too. something like

$filename = md5(time() . $_SERVER['REMOTE_ADDR'] . "some other string") . ".jpg";

would create a filename thats being generated out of the timestamp, user ip and a random salt-string you can choose freely.

you could also use the auto-increment value of the id of the database row of the file as the file name (if you store it in a database). to make it harder to guess, concatinate the id with a timestamp or also apply md5() to it. just another idea - but all in all, there are many, many ways to accomplish this task.

phpnewbi

Thanks for the replys. I used time() has it was already inserted into the ad... so I just put it in the $title place.

If I use microtime() can I just change it out where time() is and thats it? Or do I have to do something so the script recognizes what microtime() is?

Thanks! 🙂

sid

theoretically yes, the best would be you just check the manual page (see link in my post above)

rowanparker

Don't forget uniqid.

Weedpacket

$filename = md5(time() . $_SERVER['REMOTE_ADDR'] . "some other string") . ".jpg";

For fun you could use the MD5 of the uploaded file itself .... that's assuming that the purpose is to normalise filenames and to prevent collisions, rather than make it hard to guess what name it will get. Of course, you will get a collision if two people upload bit-for-bit identical image files (or one person uploads the same image twice).