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How to list exported functions in a shared lib on Ubuntu

Answer 1

+3 A:

Try the nm utility.

GNU nm lists the symbols from object files objfile.... If no object files are listed as arguments, nm assumes the file a.out. [reference]

rpg 2010-02-16 16:58:23

**nm -C --defined-only -g libXXX.so** for C++

Nikolai N Fetissov 2010-02-16 17:01:33

Thanks for that. It appears my symbol is exported, but undefined (it has a 'U' next to the function name). How can a function be exported and yet be undefined (IIRC, a linker option prevents this kind of absurbity). More importantly, what can I do to fix it?

Stick it to THE MAN 2010-02-16 17:09:20

By "Fixing it", I mean how can I ensure that my functions are exported AND DEFINED in the shared library?

Stick it to THE MAN 2010-02-16 17:10:30

Could it be that the undefined symbol is contained in another shared object? Check out Void's advice.

rpg 2010-02-16 20:42:46

Answer 2

A:

Is your shared library in the library load path or in the application's run-time search path? It sounds like the dynamic linker can't find your library. Try running ldd on your application to see if the library can be found at run-time, e.g.:

$ ldd /usr/bin/less
    linux-gate.so.1 =>  (0x0072a000)
    libncurses.so.5 => /lib/libncurses.so.5 (0x00c68000)
    libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0x007c7000)
    libdl.so.2 => /lib/tls/i686/cmov/libdl.so.2 (0x00286000)
    /lib/ld-linux.so.2 (0x002a1000)

See the ld.so(8) man page for additional details on library search paths.

Void 2010-02-16 18:00:28

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How to list exported functions in a shared lib on Ubuntu

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