Why there is a need to Convert the unique filename to a unique number? How is this gonna help?

Why are you asking me the same question as I asked you?

The hash is a mathematical algorithm of producing a string based on a contents file

I showed the hash operating on the file path, not its content.

the .html file can be: 1. renamed 2. moved 3. contents altered

Thus, you want to be able to consider two files with different names, different locations and different contents as "the same file".

Without you arranging to place some piece of information within those files that can be searched for, to uniquely identify them; those criteria mean that any two files could be considered the same, which is a nonsense; which is why I ignored the possibility that you actually meant that; and assumed your description was lacking precision.

However, inserting a piece of information -- say a custom html-like tag or html comment -- into each html file -- regardless of whether the are 100's 1000's or 100s of 1000s would be the works of a few minutes. At least it would be for Perl.

those criteria mean that any two files could be considered the same, which is a nonsense; which is why I ignored the possibility that you actually meant that; and assumed your description was lacking precision.

No, it is not a nonsense. Imagine me in real life:

1. i'am altering my real name
2. i'am changing the location of where i live
3. i face lift myself.

Am i not still the same person i used to be?

However, inserting a piece of information -- say a custom html-like tag or html comment -- into each html file -- regardless of whether the are 100's 1000's or 100s of 1000s would be the works of a few minutes. At least it would be for Perl.

And what if the .html page gets rewritten by DreamWeaver or Joomla and the certain piece of information is overwwitten, thus gets lost?

Am i not still the same person i used to be?

Perhaps.

Upon being presented with an award by the council for saving money by using the same broom for 20 years, a character in a famous British sitcom said:

And that's what I've done. Maintained it for 20 years. This old broom's had 17 new heads and 14 new handles in its time.

To which the inevitable response is, how the hell can it be the same bloody broom then?

This is an ancient question, best known as Theseus' paradox.

Most of the cells in your body aren't much more than a few years old. (Some are in it for the long haul - after adolescence we don't grow many more brain cells for example - we just start putting them to better use!) So are you the same person that you were 10 years ago?

If you think you are, what makes you the same person? What has been the constant factor that you can point to over the last ten years that allows you to consider yourself to be a continuation of the same person?

Now, to more practical matters, what constant factor can you point to over file changes that allows you to consider two files to be the same file? Write an algorithm to detect that factor. Job done.

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

Am i not still the same person i used to be?

Has your DNA changed? If not, you are detectably the same person.

So now all you need is something to detect in your files to make the determination.

But if Dreamweaver glitches and empties the file, you're stuffed.

---

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.