How to list imported symbols in ELF executable?

Question

For PE executable, I can list the imported symbols using

dumpbin /imports FILE.EXE

or using the depends utility which is GUI application.

`nm ELF-binary' just returns "no symbols".

see also [list the symbols in a .so file](http://stackoverflow.com/questions/34732/how-do-i-list-the-symbols-in-a-so-file) — bartolo-otrit, Aug 20 '16 at 17:24

score 24 · Accepted Answer · answered Jul 09 '10 at 13:50

24

Try objdump -T 'ELF-file'

answered Jul 09 '10 at 13:50

Daniele Santi

2,244
1
22
17

I thought objdump -T worked mainly on shared libraries... – jim mcnamara Jul 09 '10 at 14:35
well... not really, if I do: objdump -t /bin/ls it returns: "SYMBOL TABLE: no symbols", with -T (which lists DYNAMIC SYMBOL TABLE) outputs a lot of data, like: "00000000 DF *UND* 00000000 GLIBC_2.0 strchr" – Daniele Santi Jul 09 '10 at 15:11

score 8 · Answer 2 · answered Feb 21 '15 at 00:41

The output from objdump is a little excessive for this purpose, and requires a good bit of parsing to find the actual imports.

I prefer readelf for this purpose:

readelf -d dynamic-buffer-test

Dynamic section at offset 0x630a8 contains 23 entries:
 Tag                Type                 Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libstdc++.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgcc_s.so.1]

As you can see, the required libraries are marked with "NEEDED".

It just depends on the mode in which you invoke it. Try `objdump -p /path/to/binary | grep NEEDED`. — sherrellbc, Nov 08 '16 at 21:37

score 5 · Answer 3 · answered Mar 15 '15 at 00:30

5

I prefer readelf.

readelf -s <file>

answered Mar 15 '15 at 00:30

Grazfather

51
1
1

That only lists required libraries. The question is about what symbols are imported from said libraries. – Alcaro Jun 13 '17 at 10:49

score 2 · Answer 4 · answered Nov 08 '16 at 21:39

Along with the other answers posted here I would like to propose another. The contents printed are a function of the file format, where ELF lends itself nicely to solving this problem.

objdump -p /path/to/binary | grep NEEDED

The grep simply extracts the contents of the Dynamic Section, but its the format of the objdump -p output that makes this a simple solution.

How to list imported symbols in ELF executable?

4 Answers4