disasm x86 machine code

disasm_x86.py

import argparse

from capstone import (
    Cs,
    CS_ARCH_X86,
    CS_MODE_32,
    CS_OPT_SYNTAX_ATT,
)


OFFSET = 0x08048060
md = Cs(CS_ARCH_X86, CS_MODE_32)
md.syntax = CS_OPT_SYNTAX_ATT


def disasm(code: bytes):
    for address, size, mnemonic, op_str in md.disasm_lite(code, offset=OFFSET):
        print("0x{0:x}\t{1:d}\t{2:s}\t{3:s}".format(address, size,
                                                    mnemonic, op_str))


def type_hex(num):
    if num is not None:
        return int(num, base=16)


def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument("file", nargs='?', default="code",
                        type=argparse.FileType("rb"))
    parser.add_argument("--seek", default=None, type=type_hex)
    parser.add_argument("--size", default=None, type=type_hex)
    args = parser.parse_args()

    if args.seek is not None and args.size is None:
            parser.error("--seek requires --size.")
    return args


def main():
    args = parse_args()
    with args.file as fd:
        if args.seek is not None:
            fd.seek(args.seek)
            code = fd.read(args.size)
        else:
            code = fd.read()
        disasm(code)


if __name__ == '__main__':
    main()