I expected to see number of symbols in the libc.so.6 file including printf.  I used the nm tool to find them, however it says there is no symbol in libc.so.6.
Why nm shows no symbols for /lib/i386-linux-gnu/libc.so.6?
linux;shared library;symbol table;nm
It's probably got its regular symbols stripped and what's left is its dynamic symbols, which you can get with nm -D.