looking for the source to sleep()
 

There must be tools to answer the following questions

1. What library contains a specific function (such as sleep)?

2. What functions does a given library supply?

What are those tools, please ?


I presume, if I knew the library, I could easily find the source but I'd be happy if you would educate me if you sense a misunderstanding.

purgatory_red

Well, for the second question you might try using the nm command
Something like lis:

nm /usr/lib/libm.so | grep W