tonetheman / ld_wrap

testing ld wrap in gcc

playing with wrap

with ld

libtony.so

Made a shared library called libtony.so tonylib.c and tonylib.h

to create the library run make libtony.so

testwrap

Next create an exe called testwrap testwrap.c run make testwrap

this is the line that makes the magic gcc -o testwrap testwrap.c -L. -ltony -Wl,--wrap=tony_is_cool

The --wrap=tony_is_cool causes ld to find a symbol that matches that name And instead calls __wrap_<SYMBOL> in this case __wrap_tony_is_cool

You can also refer back to the original symbol with __real_<SYMBOL>

When you compile you will get a warning about and implicit declaration of the __real_tony_is_cool function but this is just a warning.

type make run

to see it work.