Question

I wrote a C++ library which builds fine (gcc 4.6.3), until I tried linking with openssl. I’m on Ubuntu 12.04.

Using sudo apt-get install libssl-dev the openssl includes are installed in /usr/include/openssl. But using -I /usr/include causes dozens of errors with the C++ libraries. They appear to be using /usr/local/include/ and this new include path is causing conflicts.

I see that versions of the C++ libraries are in both

    /usr/include/
    /usr/local/include/

with the version in /usr/include more up-to-date.

How can I direct gcc to to use /usr/include/c++ for standard libraries? And would that be the correct way to solve my problem?

Answer 1

You shouldn’t need to mess with -I flags. Headers can be included with

#include <openssl/[header name here]>

Libraries can be linked in using -l<library name>. For example, you would link libssl with:

g++ <other options> -lssl <files>