asmx86.py

#! /usr/bin/python

## GENERAL

def myhex(val):
    h = hex(val)
    if h[-1] == "L":
        return h[:-1]
    return h

## NASM
def nasm(code, path_nasm = 'nasm'):
    """ Assemble code using nasm
    
    >>> nasm("int 0x80")
    '\xcd\x80'
    """
    import subprocess
    import tempfile
    import os
    input_file = tempfile.NamedTemporaryFile(delete=False)
    output_file = tempfile.NamedTemporaryFile(delete=False)
    input_file.write(code)
    input_file.close()
    p = subprocess.Popen([path_nasm,
     '-fbin',
     '-o',
     output_file.name,
     input_file.name])
    p.communicate()
    p.wait()
    s = output_file.read()
    output_file.close()
    try:
        os.remove(input_file.name)
        os.remove(output_file.name)
    except Exception:
        pass
    return s


if __name__ == '__main__':
    import sys
    if len(sys.argv) < 2:
        s = sys.stdin.read()
    else:
        s = " ".join(sys.argv[1:])
    res = nasm("[BITS 64]\n" + s)
    print("repr: {}".format(repr(res)))
    print("hex: {}".format(res.encode("hex")))
    print("len: 0x{:X}".format(len(res)))