How can I check a running process to see what shared libraries it is using?

Question

On Linux, I have a C++ application that is using dlopen() to load some shared libraries, but I'm suspicious that the version of the shared library being loaded is not the one I expect because my debugging trace code does not appear to be executed.

Is there a way to check a running process to query all the shared libraries it currently has open and the path to each of those libraries? In other words, something akin to ldd but that works on a running executable and lists runtime loaded libraries as well.

Answer 1

If you want to know the library files a program have opened, you can try pmap. For example, if we want to know the libraries that bash process 3860 have opened, the result could be:

3860:   bash
08048000    880K r-x--  /bin/bash
08124000      4K r----  /bin/bash
08125000     20K rw---  /bin/bash
0812a000     20K rw---    [ anon ]
099ae000    348K rw---    [ anon ]
b715c000     44K r-x--  /lib/i386-linux-gnu/libnss_files-2.15.so
b7167000      4K r----  /lib/i386-linux-gnu/libnss_files-2.15.so
b7168000      4K rw---  /lib/i386-linux-gnu/libnss_files-2.15.so
b7169000     88K r-x--  /lib/i386-linux-gnu/libnsl-2.15.so
b717f000      4K r----  /lib/i386-linux-gnu/libnsl-2.15.so
b7180000      4K rw---  /lib/i386-linux-gnu/libnsl-2.15.so
b7181000      8K rw---    [ anon ]
b7183000     28K r-x--  /lib/i386-linux-gnu/libnss_compat-2.15.so
b718a000      4K r----  /lib/i386-linux-gnu/libnss_compat-2.15.so
b718b000      4K rw---  /lib/i386-linux-gnu/libnss_compat-2.15.so
b71a1000      4K r----  /usr/lib/locale/locale-archive
b71a2000   1428K r----  /usr/lib/locale/locale-archive
b7307000   2048K r----  /usr/lib/locale/locale-archive
b7507000      4K rw---    [ anon ]
b7508000   1676K r-x--  /lib/i386-linux-gnu/libc-2.15.so
b76ab000      8K r----  /lib/i386-linux-gnu/libc-2.15.so
b76ad000      4K rw---  /lib/i386-linux-gnu/libc-2.15.so
b76ae000     16K rw---    [ anon ]
b76b2000     12K r-x--  /lib/i386-linux-gnu/libdl-2.15.so
b76b5000      4K r----  /lib/i386-linux-gnu/libdl-2.15.so
b76b6000      4K rw---  /lib/i386-linux-gnu/libdl-2.15.so
b76b7000    112K r-x--  /lib/i386-linux-gnu/libtinfo.so.5.9
b76d3000      8K r----  /lib/i386-linux-gnu/libtinfo.so.5.9
b76d5000      4K rw---  /lib/i386-linux-gnu/libtinfo.so.5.9
b76d8000     28K r--s-  /usr/lib/i386-linux-gnu/gconv/gconv-modules.cache
b76df000     40K r-x--  /lib/i386-linux-gnu/libnss_nis-2.15.so
b76e9000      4K r----  /lib/i386-linux-gnu/libnss_nis-2.15.so
b76ea000      4K rw---  /lib/i386-linux-gnu/libnss_nis-2.15.so
b76eb000      8K rw---    [ anon ]
b76ed000      4K r-x--    [ anon ]
b76ee000    128K r-x--  /lib/i386-linux-gnu/ld-2.15.so
b770e000      4K r----  /lib/i386-linux-gnu/ld-2.15.so
b770f000      4K rw---  /lib/i386-linux-gnu/ld-2.15.so
bfbbf000    132K rw---    [ stack ]
 total     7152K

Wish it would be of help for you.