替换 Python 文件中的特定字符串（之后）

Question

Replace specific string (below) in file in Python

I have a text file that is something like the following:

test   al,al
jne    0x514 <asm4+23>
mov    DWORD PTR [ebp-0x8],0x1
jmp    0x587 <asm4+138>
mov    edx,DWORD PTR [ebp-0x8]

I need the result to be like this

test   al,al
jne    asm4+23
mov    DWORD PTR [ebp-0x8],0x1
jmp    asm4+138
mov    edx,DWORD PTR [ebp-0x8]

Answer 1

This could work for your example. I have used python regular expressions

import re

regex = r"(0.+<)(.+)>"
input_string="""
test   al,al
jne    0x514 <asm4+23>
mov    DWORD PTR [ebp-0x8],0x1
jmp    0x587 <asm4+138>
mov    edx,DWORD PTR [ebp-0x8]

"""
output=re.sub(r"(0.+<)(.+)>", r"\2", input_string)
print(output)

Hope this helps

Answer 2

You can use just ".startswith" method:

test = """
    test   al,al
    jne    0x514 <asm4+23>
    mov    DWORD PTR [ebp-0x8],0x1
    jmp    0x587 <asm4+138>
    mov    edx,DWORD PTR [ebp-0x8]
    """.splitlines()

i = 0
while i < len(test):
    if test[i].startswith("jne"):
        test[i] = "jne    0x514 <asm4+23>"
    elif test[i].startswith("jmp"):
        test[i] = "jmp    0x587 <asm4+138>"
    i += 1

print("\n".join(test))

Answer 3

You're converting disassembly into something that can be re-assembled.

Instead of post-processing GDB or objdump -drwC -Mintel output, use a disassembler that outputs in actual GAS or NASM syntax in the first place, with extra info in comments. Specifically for x86, Agner Fog's objconv .

See How to generate assembly code with gcc that can be compiled with nasm for example output.

(I don't think it can target GAS .intel_syntax , only GAS, NASM/YASM, or MASM. But GAS .intel_syntax is MASM-like except for the directives so that may be useful. Or if you don't mind AT&T syntax, it can be assembled directly without installing NASM.)