need help with installing shared libraries on linux

Question

Hi,

I am new to linux and trying to get the Ajax Push engine server to work on Ubuntu 9.04. I installed the server from source it fails the check that it does by using its own javascript framework.

The problem is that it fails to load the modules and the output that i get in the terminal when i start it is.

[Module] Failed to load ../modules/lib/libmod_spidermonkey.so [Invalid library] (libmysac.so.0.0: cannot open shared object file: No such file or directory)

i thought i had to install mysac lib as a shared lib, so after some searching i copied the libmysac.so to /usr/local/lib/ and upon running ldconfig there it created the symlink. But still it gived the same error.

Now I copied the libmod_spidermonkey.so in the shared lib dir. But this time ldconfig did not create any symlinks.

I am really confused and looking for some pointers . Please help

Answer 1

ldconfig creates, updates, and removes the necessary links and cache (for use by the run-time linker, ld.so) to the most recent shared libraries found in the directories specified on the command line, in the file /etc/ld.so.conf, and in the trusted directories (/usr/lib and /lib).

You may try ldd libmod_spidermonkey.so to see if it finds all shared libraries it needs. If it says not found, you need to see why.

If it needs libmysac.so.0.0 you need to have a symlink or a file with such name in directories mentioned in /etc/ld.so.conf (or one of files in /etc/ld.so.conf.d/). After adding a library to these directories, you need to execute ldconfig.

Another solution is setting LD_LIBRARY_PATH shell environment.

export LD_LIBRARY_PATH=/usr/local/lib:/my/dir/with/libs

No ldconfig is needed in this case.