Find the algorithms behind standard library functions

Question

I always wondered how can one access to the algorithms behind well-known C (or any other language) functions, like printf(), scanf(), isdigit() and so on. Is there any official repository for those? Or is there any way to access them once you have the language library installed in your pc?

PS - the named functions are merely representative. I would like to access the algorithms behind standard library functions in the most popular languages.

Answer 1

Did you check these posts:

• Where can I find the source code for all the C standard libraries?
• C - Source code of functions in standard library

I think this will at least avoid getting duplicated answers