Immediate Dependencies Only
1objdump -x a.out | grep NEEDED # or -p
2
3 NEEDED libstdc++.so.6
4 NEEDED libgcc_s.so.1
5 NEEDED libc.so.6
Alternative:
1readelf -d a.out | grep NEEDED
2
3 0x0000000000000001 (NEEDED) Shared library: [libstdc++.so.6]
4 0x0000000000000001 (NEEDED) Shared library: [libgcc_s.so.1]
5 0x0000000000000001 (NEEDED) Shared library: [libc.so.6]
Full Dependencies
1$ ldd a.out
2 linux-vdso.so.1 (0x00007ffff651a000)
3 libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fcc5ef20000)
4 libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fcc5ed00000)
5 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fcc5e900000)
6 libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fcc5e560000)
7 /lib64/ld-linux-x86-64.so.2 (0x00007fcc5f600000)
With hierarchy among shared libraries:
1$ lddtree a.out
2a.out => ./a.out (interpreter => /lib64/ld-linux-x86-64.so.2)
3 libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6
4 libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6
5 ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
6 libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1
7 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
8
9$ lddtree -a a.out # show duplicated dependencies
10a.out => ./a.out (interpreter => /lib64/ld-linux-x86-64.so.2)
11 libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6
12 libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6
13 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
14 ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
15 ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
16 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
17 ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
18 ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
19 libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1
20 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
21 ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
22 libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1
23 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
24 ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
25 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
26 ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
Note that lddtree can be installed by sudo apt install pax-utils.
Difference
From the top answer of this question :
objdumpis simply dumping what the object itself lists as libraries containing unresolved symbols.
lddis listing which librariesld.sowould actually load. And it follows the graph backward, so that you can see what would be loaded by those libraries.
