How to show all shared libraries used by executables in Linux?

1. Use ldd to list shared libraries for each executable.
2. Cleanup the output
3. Sort, compute counts, sort by count

To find the answer for all executables in the "/bin" directory:

find /bin -type f -perm /a+x -exec ldd {} \; \
| grep so \
| sed -e '/^[^\t]/ d' \
| sed -e 's/\t//' \
| sed -e 's/.*=..//' \
| sed -e 's/ (0.*)//' \
| sort \
| uniq -c \
| sort -n

Change "/bin" above to "/" to search all directories.

Output (for just the /bin directory) will look something like this:

  1 /lib64/libexpat.so.0
  1 /lib64/libgcc_s.so.1
  1 /lib64/libnsl.so.1
  1 /lib64/libpcre.so.0
  1 /lib64/libproc-3.2.7.so
  1 /usr/lib64/libbeecrypt.so.6
  1 /usr/lib64/libbz2.so.1
  1 /usr/lib64/libelf.so.1
  1 /usr/lib64/libpopt.so.0
  1 /usr/lib64/librpm-4.4.so
  1 /usr/lib64/librpmdb-4.4.so
  1 /usr/lib64/librpmio-4.4.so
  1 /usr/lib64/libsqlite3.so.0
  1 /usr/lib64/libstdc++.so.6
  1 /usr/lib64/libz.so.1
  2 /lib64/libasound.so.2
  2 /lib64/libblkid.so.1
  2 /lib64/libdevmapper.so.1.02
  2 /lib64/libpam_misc.so.0
  2 /lib64/libpam.so.0
  2 /lib64/libuuid.so.1
  3 /lib64/libaudit.so.0
  3 /lib64/libcrypt.so.1
  3 /lib64/libdbus-1.so.3
  4 /lib64/libresolv.so.2
  4 /lib64/libtermcap.so.2
  5 /lib64/libacl.so.1
  5 /lib64/libattr.so.1
  5 /lib64/libcap.so.1
  6 /lib64/librt.so.1
  7 /lib64/libm.so.6
  9 /lib64/libpthread.so.0
 13 /lib64/libselinux.so.1
 13 /lib64/libsepol.so.1
 22 /lib64/libdl.so.2
 83 /lib64/ld-linux-x86-64.so.2
 83 /lib64/libc.so.6

Edit - Removed "grep -P"

to learn what libraries a binary uses, use ldd

ldd path/to/the/tool

You'd have to write a little shell script to get to your system-wide breakdown.

With ldd you can get the libraries that tools use. To rank the usage of libraries for a set of tool you can use something like the following command.

ldd /bin/* /usr/bin/* ... | sed -e '/^[^\t]/ d; s/^\t\(.* => \)\?\([^ ]*\) (.*/\2/g' | sort | uniq -c

(Here sed strips all lines that do not start with a tab and the filters out only the actual libraries. With sort | uniq -c you get each library with a count indicating the number of times it occurred.)

You might want to add sort -g at the end to get the libraries in order of usage.

Note that you probably get lines two non-library lines with the above command. One of static executables ("not a dynamic executable") and one without any library. The latter is the result of linux-gate.so.1 which is not a library in your file system but one "supplied" by the kernel.

One more option can be just read the file located at

/proc/<pid>/maps

For example is the process id is 2601 then the command is

cat /proc/2601/maps

And the output is like

7fb37a8f2000-7fb37a8f4000 r-xp 00000000 08:06 4065647                    /usr/lib/x86_64-linux-gnu/libproxy/0.4.15/modules/network_networkmanager.so
7fb37a8f4000-7fb37aaf3000 ---p 00002000 08:06 4065647                    /usr/lib/x86_64-linux-gnu/libproxy/0.4.15/modules/network_networkmanager.so
7fb37aaf3000-7fb37aaf4000 r--p 00001000 08:06 4065647                    /usr/lib/x86_64-linux-gnu/libproxy/0.4.15/modules/network_networkmanager.so
7fb37aaf4000-7fb37aaf5000 rw-p 00002000 08:06 4065647                    /usr/lib/x86_64-linux-gnu/libproxy/0.4.15/modules/network_networkmanager.so
7fb37aaf5000-7fb37aafe000 r-xp 00000000 08:06 4065646                    /usr/lib/x86_64-linux-gnu/libproxy/0.4.15/modules/config_gnome3.so
7fb37aafe000-7fb37acfd000 ---p 00009000 08:06 4065646                    /usr/lib/x86_64-linux-gnu/libproxy/0.4.15/modules/config_gnome3.so
7fb37acfd000-7fb37acfe000 r--p 00008000 08:06 4065646                    /usr/lib/x86_64-linux-gnu/libproxy/0.4.15/modules/config_gnome3.so
7fb37acfe000-7fb37acff000 rw-p 00009000 08:06 4065646                    /usr/lib/x86_64-linux-gnu/libproxy/0.4.15/modules/config_gnome3.so
7fb37acff000-7fb37ad1d000 r-xp 00000000 08:06 3416761                    /usr/lib/x86_64-linux-gnu/libproxy.so.1.0.0
7fb37ad1d000-7fb37af1d000 ---p 0001e000 08:06 3416761                    /usr/lib/x86_64-linux-gnu/libproxy.so.1.0.0
7fb37af1d000-7fb37af1e000 r--p 0001e000 08:06 3416761                    /usr/lib/x86_64-linux-gnu/libproxy.so.1.0.0
7fb37af1e000-7fb37af1f000 rw-p 0001f000 08:06 3416761                    /usr/lib/x86_64-linux-gnu/libproxy.so.1.0.0
7fb37af1f000-7fb37af21000 r-xp 00000000 08:06 4065186                    /usr/lib/x86_64-linux-gnu/gio/modules/libgiolibproxy.so
7fb37af21000-7fb37b121000 ---p 00002000 08:06 4065186                    /usr/lib/x86_64-linux-gnu/gio/modules/libgiolibproxy.so
7fb37b121000-7fb37b122000 r--p 00002000 08:06 4065186                    /usr/lib/x86_64-linux-gnu/gio/modules/libgiolibproxy.so
7fb37b122000-7fb37b123000 rw-p 00003000 08:06 4065186                    /usr/lib/x86_64-linux-gnu/gio/modules/libgiolibproxy.so

If you don't care about the path to the executable file -

ldd `which <executable>` # back quotes, not single quotes

I found this post very helpful as I needed to investigate dependencies from a 3rd party supplied library (32 vs 64 bit execution path(s)).

I put together a Q&D recursing bash script based on the 'readelf -d' suggestion on a RHEL 6 distro.

It is very basic and will test every dependency every time even if it might have been tested before (i.e very verbose). Output is very basic too.

#! /bin/bash

recurse ()
# Param 1 is the nuumber of spaces that the output will be prepended with
# Param 2 full path to library
{
#Use 'readelf -d' to find dependencies
dependencies=$(readelf -d ${2} | grep NEEDED | awk '{ print $5 }' | tr -d '[]')
for d in $dependencies; do
   echo "${1}${d}"
   nm=${d##*/}
   #libstdc++ hack for the '+'-s
   nm1=${nm//"+"/"\+"}
   # /lib /lib64 /usr/lib and /usr/lib are searched
   children=$(locate ${d} | grep -E "(^/(lib|lib64|usr/lib|usr/lib64)/${nm1})")
   rc=$?
   #at least locate... didn't fail
   if [ ${rc} == "0" ] ; then
      #we have at least one dependency
      if [ ${#children[@]} -gt 0 ]; then
         #check the dependeny's dependencies
         for c in $children; do
          recurse "  ${1}" ${c}
         done
      else
         echo "${1}no children found"
      fi
   else
      echo "${1}locate failed for ${d}"
   fi
done
}
# Q&D -- recurse needs 2 params could/should be supplied from cmdline
recurse "" !!full path to library you want to investigate!!

redirect the output to a file and grep for 'found' or 'failed'

Use and modify, at your own risk of course, as you wish.