How can you inspect an executable file?

readelf -a shows the ELF structure (headers, sections, symbols); objdump -d disassembles the machine code back to assembly.

# Show all ELF information
$ readelf -a p24
# Disassemble
$ objdump -d p24

Example objdump output:

p24:     file format elf64-x86-64
...
Disassembly of section .text:

00000000000010c0 <_start>:
  10c0: f3 0f 1e fa        endbr64
  10c4: 31 ed              xor    %ebp,%ebp
  10c6: 49 89 d1           mov    %rdx,%r9
  ...
00000000000011a9 <main>:
  11a9: f3 0f 1e fa        endbr64
  11ad: 55                 push   %rbp
  11ae: 48 89 e5           mov    %rsp,%rbp

The output shows: address, machine code bytes, and assembly mnemonic.

Go deeper:

• Executable and Linkable Format (Wikipedia) — the ELF layout (headers, sections, program headers) that readelf/objdump walk when you inspect a binary.
• Disassembler (Wikipedia) — how objdump recovers assembly from machine code, and the hard parts (code-vs-data, variable-width instructions).