problem with file_exists caching even when clearstatcache() is called

[Andrew Crowe]

Hi guys,

I've created this little function to check whether a user has uploaded a
file with the same name as an existing file, and if so rename it to
file-1.jpg, file-2.jpg etc.

clearstatcache( );
if(file_exists( "$BasePath/$FileName.jpg") ){
$extra=1;
while(file_exis ts("$BasePath/$FileName-$extra.jpg")){
$extra++;
}
$FileName="$Fil eName-$extra";
}

However if files are deleted outside PHP file_exists still returns true so
it keeps adding higher numbers to the files.


Is there any way I can get round this? The strange thing is if I call
file_exists() on a folder it works fine.

--
Regards,
Andrew Crowe

[Andrew Crowe]

Re: problem with file_exists caching even when clearstatcache( ) is called

Sorry forgot to mention I'm using PHP5 RC2 on Windows 2000 / IIS (isapi)

--
Regards,
Andrew Crowe

[Chung Leong]

Re: problem with file_exists caching even when clearstatcache( ) is called

"Andrew Crowe" <andrewcrowe_uk @yahoo.co.uk> wrote in message
news:40752e40$0 $3940$afc38c87@ news.easynet.co .uk...[color=blue]
> Hi guys,
>
> I've created this little function to check whether a user has uploaded a
> file with the same name as an existing file, and if so rename it to
> file-1.jpg, file-2.jpg etc.
>
> clearstatcache( );
> if(file_exists( "$BasePath/$FileName.jpg") ){
> $extra=1;
> while(file_exis ts("$BasePath/$FileName-$extra.jpg")){
> $extra++;
> }
> $FileName="$Fil eName-$extra";
> }
>
> However if files are deleted outside PHP file_exists still returns true so
> it keeps adding higher numbers to the files.
>
>
> Is there any way I can get round this? The strange thing is if I call
> file_exists() on a folder it works fine.
>
> --
> Regards,
> Andrew Crowe
>[/color]

There's a race condition in your code. Between the time when file_exists()
was called and the subsequent move_uploaded_f ile() a file with that name
could conceivably have been created. A better approach is to keep calling
move_uploaded_f ile() until it works:

$extra = 1;
while(!@move_up load_file($tmpn ame, $filename)) {
$filename = "$BasePath/$FileName-$extra.jpg";
$extra++;
}

This bypasses the caching issue as well.