How do you find what version of libstdc++ library is installed on your linux machine?

Question

I found the following command: strings /usr/lib/libstdc++.so.6 | grep GLIBC from here. It seems to work but this is an ad-hoc/heuristic method.

Is there a specific command that can be used to query the library version of C++? Or is the method I found the accepted method?

Answer 1

To find which library is being used you could run

 $ /sbin/ldconfig -p | grep stdc++     libstdc++.so.6 (libc6) => /usr/lib/libstdc++.so.6 

The list of compatible versions for libstdc++ version 3.4.0 and above is provided by

 $ strings /usr/lib/libstdc++.so.6 | grep LIBCXX  GLIBCXX_3.4  GLIBCXX_3.4.1  GLIBCXX_3.4.2  ... 

For earlier versions the symbol GLIBCPP is defined.

The date stamp of the library is defined in a macro __GLIBCXX__ or __GLIBCPP__ depending on the version:

// libdatestamp.cxx #include <cstdio>  int main(int argc, char* argv[]){ #ifdef __GLIBCPP__     std::printf("GLIBCPP: %d\n",__GLIBCPP__); #endif #ifdef __GLIBCXX__     std::printf("GLIBCXX: %d\n",__GLIBCXX__); #endif    return 0; }  $ g++ libdatestamp.cxx -o libdatestamp $ ./libdatestamp GLIBCXX: 20101208 

The table of datestamps of libstdc++ versions is listed in the documentation:

Answer 2

What exactly do you want to know?

The shared library soname? That's part of the filename, libstdc++.so.6, or shown by readelf -d /usr/lib64/libstdc++.so.6 | grep soname.

The minor revision number? You should be able to get that by simply checking what the symlink points to:

$ ls -l  /usr/lib/libstdc++.so.6 lrwxrwxrwx. 1 root root 19 Mar 23 09:43 /usr/lib/libstdc++.so.6 -> libstdc++.so.6.0.16 

That tells you it's 6.0.16, which is the 16th revision of the libstdc++.so.6 version, which corresponds to the GLIBCXX_3.4.16 symbol versions.

Or do you mean the release it comes from? It's part of GCC so it's the same version as GCC, so unless you've screwed up your system by installing unmatched versions of g++ and libstdc++.so you can get that from:

$ g++ -dumpversion 4.6.3 

Or, on most distros, you can just ask the package manager. On my Fedora host that's

$ rpm -q libstdc++ libstdc++-4.6.3-2.fc16.x86_64 libstdc++-4.6.3-2.fc16.i686 

As other answers have said, you can map releases to library versions by checking the ABI docs