Hi

I am trying to compile one of my c++ codes in slackware 13 and I always get linking problems with SDL libraries.
How can I check the linking is correct for SDL libraries? Where can be a problem?
I always get undefined reference for SDL functions like SDL_init ...

Help, help

Is the SDL library installed?

Do you know where it is?
(eg "find /usr -name libsdl\*)

You would use "-lSDL" to link in the library, and something like "-L/usr/local/lib" if it is not installed in /lib or /usr/lib.

Yes I found the libraries:
But the link in process I didn't understand.
What do you mean with -lSDL. Use it as a switch for what command? For ld, or gcc??
Sorry if the question is stupid I never done linking before.

It looks like that the trouble is with kdevelop4 - I just cannot create SDL application the way I did before.
I am starting consider the downgrade to kdevelop 3.5.5.

Those command line switches are for the linker 'ld'. The link is the final stage of an application build process, when all the individual parts get 'linked' together.

Because you are using a development environment, you don't see these stages explicitly. But you do have control over the flags/switches that are given at each stage.

The '-lSDL' is a flag that tells the linker to look for a particular library that your application requires. This flag would be somewhere in the libraries section of the project/subproject options.

A flag like '-L/usr/lib64' tells the linker where to search for library files. This flag (or at least the path) would be somewhere in the linker flags section of the project configuration options. You may not need this (/usr/lib64 would often be in the standard search path).

Note that this is a later stage than the compilation stage (when header files are being included). Just because the compiler 'gcc' can find the header files for a library does not mean that the loader 'ld' can find the binary files that are the compiled library code, because these files are normally in different places. The undefined reference errors you are getting indicate that the compilation step succeeded, but the link stage could not find the functions which were referred to by the header source code.

Incidentally, do you have a '/usr/lib' directory on the system?

Yes I do, these files are in it.

Please post your thread in only one forum. Posting a single thread in the most relevant forum will make it easier for members to help you and will keep the discussion in one place. This thread is being closed because it is a duplicate of http://www.linuxquestions.org/questi...erence-751268/.