Still library linking problem

The_Nerd · 05-20-2004, 03:12 PM

I want my program to use the library mylib.so

mylib.so is in the same folder as my program. I DON'T want mylib.so ANYWHERE else on the system.

How do I make my program use mylib.so?

itsme86 · 05-20-2004, 03:19 PM

gcc -L. myprog.c -o myprog -lmylib

Something like that maybe

lyle_s · 05-20-2004, 03:24 PM

Given that you have a shared object in /some/nonstandard/place you have two options:

Place /some/nonstandard/place in /etc/ld.so.conf and run the ldconfig command (as root).
Place /some/nonstandard/place in the environment variable LD_LIBRARY_PATH.

For more, see man ld.so.

Lyle

The_Nerd · 05-20-2004, 03:28 PM

Quote:

Originally posted by lyle_s
Given that you have a shared object in /some/nonstandard/place you have two options:
Place /some/nonstandard/place in /etc/ld.so.conf and run the ldconfig command (as root).

Place /some/nonstandard/place in the environment variable LD_LIBRARY_PATH.

For more, see man ld.so.
Lyle

Absolutly not! I don't want to use ldconfig in anyway... LD_LIBRARY_PATH would work if I could change it upon startup in my program... except my program doesn't start... so problem.

I have already tried your idea itsme86... It won't compile, and just says "undefined reference" to every function in the lib...

I DO NOT WANT TO CHANGE/EDIT/MODIFY ANY SYSTEM SETTINGS!

Thanks for your help guys. But I am still stuck.

Mara · 05-20-2004, 03:30 PM

itsme86's suggestion should work.

The_Nerd · 05-20-2004, 03:31 PM

Dynamic linking would be fine if anyone would show me how to do it. But it has to be Windows/Linux compatible, and it has to be easy. You know, not like:

mypt1 = function1;
mypt2 = function2;
mypt3 = function3;
...................

deiussum · 05-20-2004, 03:32 PM

You could make it a static .a library instead. Another option might be to look at functions like dlopen, dlsym, etc. I haven't used those myself, but a quick look at the man page suggests they are similar to the Win32 API functions LoadLibrary and GetProcAddress...

The_Nerd · 05-20-2004, 03:33 PM

Quote:

Originally posted by Mara
itsme86's suggestion should work.

It doesn't. It doesn't complain about not being able to find the library. The linker just complains about all the undefined references....

deiussum · 05-20-2004, 03:33 PM

Quote:

Originally posted by Mara
itsme86's suggestion should work.

It'd work to compile and link, but not to run. When run, it would look for the .so file somewhere in the library paths in /etc/ld.so.conf or $LD_LIBRARY_PATH.

The_Nerd · 05-20-2004, 03:34 PM

Quote:

Originally posted by deiussum
You could make it a static .a library instead. Another option might be to look at functions like dlopen, dlsym, etc. I haven't used those myself, but a quick look at the man page suggests they are similar to the Win32 API functions LoadLibrary and GetProcAddress...

Ya... But when I tried this, I had to dlsym EVERY function in the library to a LIST of pointers... this sucked a million times over! So if there is an easy way... sure!

The_Nerd · 05-20-2004, 03:35 PM

Quote:

Originally posted by deiussum
It'd work to compile and link, but not to run. When run, it would look for the .so file somewhere in the library paths in /etc/ld.so.conf or $LD_LIBRARY_PATH.

It compiled. But wouldn't link.

deiussum · 05-20-2004, 03:39 PM

So then make it a static library file so that it isn't needed at all by the final binary.

Either that or you are going to have to put the path to it in ld.so.conf or the LD_LIBRARY_PATH and run ldconfig. I don't think there's any other choice, though I could be mistaken.

deiussum · 05-20-2004, 03:40 PM

Quote:

Originally posted by The_Nerd
It compiled. But wouldn't link.

Is your file called libmylib.so? When you use -llibraryname it expects it to be pre-pended with the lib. Still, even if you get it to link you are going to probably going to run into problems when you try to run the app, as we've been telling you...

The_Nerd · 05-20-2004, 03:40 PM

Ok then. Explain to me how Quake3, Heretic II, UT2003, and other such games for linux do the same thing I want to do???

lyle_s · 05-20-2004, 03:40 PM

How about having users run a bash/shell script that sets LD_LIBRARY_PATH, then uses exec to run the actual program.

This is the approach that the Intel C++ compiler for Linux uses; the icc command is actually a shell script.

Lyle