Readelf vs. objdump: why do you need both

Question

I need to know about the layout of the ELF file for the project I'm working on, and I noticed the presence of these tools. Why do all Linux distributions include both readelf and objdump? Are these tools related to each other? When do I prefer to use one over the other?

Answer 1

from binutils / readelf.c:

/* The difference between readelf and objdump: Both programs are capabale of displaying the contents of ELF format files, so why does the binutils project have two file dumpers ? The reason is that objdump sees an ELF file through a BFD filter of the world; if BFD has a bug where, say, it disagrees about a machine constant in e_flags, then the odds are good that it will remain internally consistent. The linker sees it the BFD way, objdump sees it the BFD way, GAS sees it the BFD way. There was need for a tool to go find out what the file actually says. This is why the readelf program does not link against the BFD library - it exists as an independent program to help verify the correct working of BFD. There is also the case that readelf can provide more information about an ELF file than is provided by objdump. In particular it can display DWARF debugging information which (at the moment) objdump cannot. */