How to override printf/scanf calls

["Bharath Ramesh" <bramesh at vt dot edu>]

I know that I can override most system calls in libc writing the function
with the right signature and then creating a shard library out of it and use
the LD_PRELOAD mechanism when I run any application. This method doesn't not
work for libc calls like printf/scanf. Writing a shared library with any of
this calls has issues as ld cant preload this shared library. The only other
option I have at the moment is to download glibc source and rebuild glibc
with appropriate changes. This makes the solution not portable, I was
wondering if there was any other way by which I could override libc calls
like printf/scanf?

Regards,

Bharath

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