Little help on how i should do this

pinehead18

I do not have a code question, more of a how should i do this question.

Essentially what is going on, is i have a site.. WHich enables people to upload pictures. To one dir in the www folder.. which is of course pics. However, i'm trying to develope a system that makes it so their can never be more than one of the file name.

Of course, i figured out that i need to rename the file as it is being uploaded however.. What shoudl i name it? What happens if the person removes that pictures and uplaods another one.. How do i manage the names then?

Please give me any input you can on this.

THank you
Anthony

sijis

my first thought is to just add a number after the file.

image name: image.jpg

then the next one would be

image1.jpg or image_1.jpg

the way it would work is like this:

when user is uploading the image

check if image filename exists
if it doesn't exists, upload the image with its orginal filename
if it does exists, find the last number given to the name and then upload the image file with a new name.

hmm.. maybe given the files name as
image_1.jpg might be easier to track what is the last number.

ohh yeah, if the user removes their image, its no big deal. when someone else uploads a file with that same name, it shouldn't be a problem, since that file doesn't exists any longer.

AstroTeg

It depends on how much info you have available at script time (such as a user ID) and what you're willing to do in regards to file names.

The increment file number approach works, but I think that might be a little more overhead then you need (you'd have to index the directory and find the last number used - not a problem if you have 10 files, but more so of a problem if you have 10,000 files).

If you have a way to identify the user or some way to identify the session (IP address?), great! Put it somewhere in there as the file name. If not, not a huge biggie.

I'd assume you'd have some sort of a base to the file name. You can be creative on this. Maybe "image" would work.

Then add a date part. You'd want to include the entire date/time info, but trim out everything that is not a number. You can do it pretty easily with the date function like this:

$mydate = date('Ymdhis');

$mydate will equal something like: 20031219130616 (you're time will vary). This is a unique number based on seconds. You could also use the Unix timestamp, but I'd think the number above is at least easier to read (you can tell its December 12, 2003 1:06pm).

Problem: If you have a super active site, its very likely you'll have people uploading images at the very same time. If so, this approach won't work too well. Thats where I'd suggest a unique identifier per user - its rather unlikely that they'd be able to upload 2 images within the same second. If you wanted to be careful about this (which I would recommend), I'd say just toss in there file_exists() on the destination before copying the file - if the file exists, pick a new time or add a number or something to the file to make it unique.

I've used this technique in the past and it works out very well. You end up with files like this:

image20031219130645.jpg

Kind of ugly, but they're nicely indexed (they'll sort very nicely) and you can still identify the time stamp for the file (not a big deal, but a handy feature for troubleshooting). Plus, there's not a lot of code required to make this work and PHP doesn't need to do a lot of indexing - it just needs to check if one file exists or not which its very quick about doing.

Of course, this is not the only way to make this work, but just an idea...

pinehead18

Wow, that is a great idea.. Thank you both for your input.

Anthony

.. I'll let you know if i have any problems while coding this

pinehead18

Ok, wellk it didn't take me long to need some assitaance.

My problem is i can't seem to get it to re-name the file. Where do i want to rename it at.. Before it is uplaoded or after? Here is what i have so far and i would really appriciate your input... On renaming it based off the date thing you helped me out with.

if (isset($_FILES['file']['name'])) {
    if ((($_FILES['file']['type'] == 'image/gif') || ($_FILES['file']['type'] == 'image/pjpeg')) && (($_FILES['file']['size']
< 512000))) {
        // Here is were i intended on renaming the file.. But for some reason can't.

    if (file_exists('pics/' . $_FILES['file']['name'])) {
        echo "File already exists!";
    } else {


        move_uploaded_file($_FILES['file']['tmp_name'], $_SERVER['DOCUMENT_ROOT'] . 'pics/' .
$_FILES['file']['name']);
            echo "File uploaded sucessfully.";
          if ($pictrue == "true") {
        unlink($oldpic);
        }
        echo $newpicname;
        echo $name;

    }
} else {
    echo "There was a problem uploading the file. Image restrictions were not met.";
}

It uploads just fine.. However my only problem seems to be the renaming part.

Please help

Thank you
Anthony

Weedpacket

Best time would be when you make the actual move: use the "unique" name in the destination part of move_uploaded_file and that's what it will be saved as.

Needless to say, this requires working out what the unique name should be before calling move_uploaded_file!

pinehead18

Well the problem is how do i do that.

such as how to i make $_FILES['file']['name']) = the new name?

Isn't it an array?

Thank you
Anthony

AstroTeg

The 2nd parameter of move_uploaded_file will be the destination of your file. When this function goes to make the file move, just have it move to the unique filename you want to set it to:

move_uploaded_file($_FILES['file']['tmp_name'], $_SERVER['DOCUMENT_ROOT'] . 'pics/' .
$yourUniqueFilenameHere);

Of course, you'll need to have figured out what the unique file name will be before you execute this code...

pinehead18

Right i was able to do that infact it even changes the name.. however it does not keep the extention instead of it being newname.jpg its newname

Any suggestions?

AstroTeg

Right, you'll have to do a little string work on the file name that was uploaded. Basically, you need to extract the extension and glue it back onto the new filename.

pinehead18

Any idea on how i might go about that with my code above?

sijis

maybe something like this?
it works for me.

notice that $img_id.jpg is used in $img_location
and during move_uploaded_file(); is move temp name to this new name (and directory).

edit: i noticed that AstroTeg already posted the code. to fix that extension problem, i just hardcoded the ext into the $img_location. Bad i know, but this code is old and not used.

$img_id = mysql_insert_id();
$img_tmp = $_FILES['img']['tmp_name'];
$img_location = "/home/location/images/gallery/$img_id.jpg";
move_uploaded_file($img_tmp, $img_location);
chmod($img_location,775);

pinehead18

Wooo after a while tryinfg to figure it out.. I used explode to grab the extention
Thank you for all of your help.