readelf vs objdump : pourquoi les deux sont-ils nécessaires

Question

J'ai besoin de me renseigner sur la mise en page du fichier ELF pour un projet sur lequel je travaille et j'ai remarqué l'existence de ces outils. Pourquoi toutes les distributions Linux incluent-elles readelf et objdump ? Ces outils se complètent-ils ? Quand préférerais-je utiliser l'un plutôt que l'autre ?

Answer 1

de 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.  */