radare2(1)

print

  pd <n> [@ <addr>]     # print disassembly for <n> instructions
                        # with optional temporary seek to <addr>

flags

  fs            # list flag-spaces
  fs <fs>       # select flag-space <fs>
  f             # print flags of selected flag-space

help

  ?*~<kw>       # '?*' list all commands and '~' grep for <kw>
  ?*~...        # '..' less mode /'...' interactive search

relocation

  > r2 -B <baddr> <exe>         # open <exe> mapped to addr <baddr>
  oob <addr>                    # reopen current file at <baddr>

Examples

Patch file (alter bytes)

  > r2 [-w] <file>
  oo+             # re-open for write if -w was not passed
  s <addr>        # seek to position
  s sym.<symbol>  # seek to symbol
  wv <data>       # write 4 byte (dword)
  wa <insn>       # write instruction (eg "wa ret" on x86)

Assemble / Disassmble (rasm2)

  rasm2 -L      # list supported archs

  > rasm2 -a x86 'mov eax, 0xdeadbeef'
  b8efbeadde

  > rasm2 -a x86 -d "b8efbeadde"
  mov eax, 0xdeadbeef