What is the difference between ldd and objdump?

Question

I am running these two commands, and I'm getting different output:

$ ldd `which ls`
    linux-gate.so.1 =>  (0x00db3000)
    libselinux.so.1 => /lib/i386-linux-gnu/libselinux.so.1 (0x00ba2000)
    librt.so.1 => /lib/i386-linux-gnu/librt.so.1 (0x007bf000)
    libacl.so.1 => /lib/i386-linux-gnu/libacl.so.1 (0x004ce000)
    libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0x00110000)
    libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0x00398000)
    /lib/ld-linux.so.2 (0x00dea000)
    libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0x00a83000)
    libattr.so.1 => /lib/i386-linux-gnu/libattr.so.1 (0x00d3d000)

and then

objdump -x `which ls` | grep NEEDED
  NEEDED               libselinux.so.1
  NEEDED               librt.so.1
  NEEDED               libacl.so.1
  NEEDED               libc.so.6

What's up with that? I thought they both gave the library dependencies? The reason I care is that I suspect ldd is the correct one, but I'm working on linux on ARM, where there is no ldd from what I can tell...

What is the difference between ldd and objdump?

2 Answers