Monday March 06, 2006 Douglas Walls' Weblog
Monday March 06, 2006 Finding a dynamic library dependency
At a customer visit this week I was asked if the compiler libraries can be reshipped with an application. And of course the answer is yes. A complete list of those libraries can be found at:
/opt/SUNWspro/READMEs/runtime.libraries
This reminded me of another question about how an application can locate library dependencies when the application can be installed in a user defined location. For example, you have an application whose dynamic library is always located relative to itself via the path ../lib, like this:
cobol% ls -laF bin prod prod/bin .
.:
total 48
drwxr-xr-x 4 bin bin 512 Mar 6 08:15 ./
drwxrwxrwx 5 bin bin 1024 Mar 5 10:23 ../
drwxr-xr-x 2 bin bin 512 Mar 5 10:37 bin/
-rw-r--r-- 1 bin bin 2178 Mar 6 08:15 myapp.c
drwxr-xr-x 3 bin bin 512 Mar 5 10:37 prod/
bin:
total 6
drwxr-xr-x 2 bin bin 512 Mar 5 10:37 ./
drwxr-xr-x 4 bin bin 512 Mar 6 08:15 ../
lrwxrwxrwx 1 bin bin 20 Mar 5 10:37 myapp -> ../prod/bin/myapp
prod:
total 6
drwxr-xr-x 3 bin bin 512 Mar 5 10:37 ./
drwxr-xr-x 4 bin bin 512 Mar 6 08:15 ../
drwxr-xr-x 2 bin bin 512 Mar 6 08:15 bin/
drwxr-xr-x 2 bin bin 512 Mar 6 08:15 lib/
prod/bin:
total 4
drwxr-xr-x 2 bin bin 512 Mar 6 08:15 ./
drwxr-xr-x 3 bin bin 512 Mar 5 10:37 ../
-rwxr-xr-x 1 bin bin 8972 Mar 6 08:33 myapp*
prod/lib:
total 4
drwxr-xr-x 2 bin bin 512 Mar 6 08:15 ./
drwxr-xr-x 3 bin bin 512 Mar 5 10:37 ../
-rwxr-xr-x 1 bin bin 8972 Mar 6 08:33 mylib.so*
cobol%
The linker provides Dynamic String Tokens that can be used to when creating the application. In this case the token is called: $ORIGIN
And would be used as follows:
% cc -o prod/bin/myapp myapp.c '-R$ORIGIN/../lib' -L prod/lib -lmylib
For details about $ORIGIN and other Dynamic String Tokens see the Linker and Libraries Guide on docs.sun.com.