Thread: upload file doubt

Hello
Is there any option at all that two users will upload the same "file name" and it will cause a problem to show them after ?

I know that the form processor is adding a unique key before the name...but hyphothetically speaking, is it possible ?

Danny

Well this can get kind of complicated. It is highly dependent on how long the unique key is and how that key is generated.

The short answer yes, it is possible, is it likely, that depends, but probably not.

The long answer...

I'll assume the unique key is made up of uppercase & lowercase letters, as well as numbers. That is a total of 62 possible characters.

If you have a key that consists of say 5 characters. The probability that any given key will be generated is 62^5, which is 1:916,132,832 (You have a better chance of being struck by lightning then get duplicate keys).

Now if you have say a 32 character unique key before the file name, then you have a one in 62^32 chance to generate duplicate keys. That is a 1:2.27265788 × 10^57 chance.

Now there are other factors that need to be considered. For simplicity lets say the key only consists of numbers, and its generating a 4 character key.

That would be 10^4, or 10,000 possible keys. Once 5,000 files have been uploaded the probability that a duplicate key is generated is 1:5000, and that a new key is generated is 1:5000.

However because (I am assuming actually), that the unique key is only a prefix, and the actually file name is still at the end. The probability that a a duplicate key will be generated for a file with the exact same name as the other file with the same key is remote.

However that also assumes that people uploading files don't have a reason to be naming files the same. If people have a propensity to name the files the same the chances will increase.

Either way it will be a freak occurrence if this happens, if it does happen the original file will be overwritten with the new one. You will never get enough uploads to get close to this ever happening (That is you shouldn't anyway on a basic vodahost plan, the amount of files that would have to be uploaded would far surpase what the TOS allows).

I hope that answers you question

I have built the Form processor used by BV, it generates a random number of 6 digits between 100000 and 999999 and it appends the file name. So chances are practically 0.