finding which shared libraries aren't used by a binary

[Stefan Puiu]

Hello,

We have a very old software project that also runs on HP-UX and that has been maintained and developed for some time by people not very familiar with UNIX. Lots of the Makefiles were just copied from one place to another and edited when a new subproject was added. Thus, lots of the linked libraries don't seem necessary.

We had this problem when building on Solaris, which is another platform we support; we had a problem with a library that we found out we didn't actually need. On Solaris you can give a command line option to the linker and it won't dynamically link any library from those specified with -l if it isn't actually used. Is there something similar for the HP-UX linker? We have aCC A.03.55 on HP-UX 11i (PA-RISC). Or something to tell which shared libraries are actually used?

[RAC_1]

ldd "executable"

chatr "executable"

[Stefan Puiu]

Thanks for replying,

So am I to understand that the libraries in the ldd output that don't show up in the list printed by chatr aren't actually used?

[ranganath ramachandra · Accepted solution]

there is no equivalent option as yet with the hpux linker. the loader loads all libraries that were specified in the link line.

you can use ldd with options such as -y, -d and -r to see what symbols are being resolved from what libraries, then grep through the listing to weed out the ones that arent really being used. e.g.
ldd -y a.out | grep "found in .*/libsuspect.sl"

you can get similar information at link time using the linker's -v option.

you can also look at the the lazy load feature (look for +lazyload in the ld(1) manpage). this will make the loader load each library only as and when it is needed, instead of at startup.