Which all processes are using shared library

Question

I have a shared library(.so file) on UNIX. I need to know what all running processes are using it. Do unix provide any such utility/command?

Answer 1

You can inspect the contents of /proc/<pid>/maps to see which files are mapped into each process. You'll have to inspect every process, but that's easier than it sounds:

$ grep -l /lib/libnss_files-2.11.1.so /proc/*/maps
/proc/15620/maps
/proc/22439/maps
/proc/22682/maps
/proc/32057/maps

This only works on the Linux /proc filesystem, AFAIK.