algorithm to convert pathname to unique number

Question

I want to convert windows pathname to unique integer.

Eg:

For pathname C:\temp\a.out, if i add ascii value of all the characters, i get 1234. But some other path can also generate the same number. So, what is the best way to generate unique numbers for different pathnames?

Answer 1

Look into Hash functions. Make sure to consider the case-insensitive nature of most Windows filenames when performing the hash.

Most likely, the language you are using provides a library function (or collection of functions) which can take the hash of a string (or just data). SHA1 is popular and has low collision.

Here on Stackoverflow there are many questions pertaining to hash functions. To get you started, simply search for "hash function". This may be a useful SO question for your case: What is a performant string hashing function that results in a 32 bit integer with low collision rates?.