It is possible to read an object file?

Question

I was curious about .obj files: I pretty much don\'t know what they are (or what they contain), so I opened them with Vim text editor and what I found inside was an

Answer 1

The readelf tool is good at showing you some details on the data:

$ readelf -a /usr/bin/readelf
ELF Header:
  Magic:   7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 
  Class:                             ELF64
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           Advanced Micro Devices X86-64
...

Some of its abilities to inspect specific sections of the executable can come in handy too:

$ readelf -p .rodata /usr/bin/readelf | more

String dump of section '.rodata':
  [     4]  R_IA64_IMM14
  [    11]  R_IA64_NONE
  ...
  [  1f58]    Personality routine: 
  [  1f70]  __gcc_personality_v0
  [  1f85]  __gxx_personality_v0
  [  1f9a]  __gcj_personality_v0
  [  1faf]  __gnu_objc_personality_v0
  ...

Actually disassembling the code is a bit of a stretch; if you compile your code with -g for debugging symbols, you can use readelf --debug-dump to read the program source, type information, etc.