lunixbochs/patchkit

patch <binary> <patchdir|file> [patchdir|file...]

def simple_patch(pt):
    # nop out a jump at the entry point
    pt.patch(pt.entry, hex='90' * 5)

    # inject assembly into the binary and return the address
    addr = pt.inject(asm='mov eax, 1; ret')

    # hook the entry point to make it call addr (ret will run the original entry point)
    pt.hook(pt.entry, addr)

def replace_free(pt):
    # pretend free() is at this address:
    old_free = 0x804fc4

    # inject a function to replace free()
    new_free = pt.inject(c=r'''
    void free_stub(void *addr) {
        printf("stubbed free(%p)\n", addr);
    }
    ''')

    # patch the beginning of free() with a jump to our new function
    pt.patch(old_free, jmp=new_free)

addr = search(data)
hook(addr, new_addr)
patch(addr, *compile arg*)
addr = inject(*compile arg*)

*compile arg* is any of the following:
  raw='data'
  hex='0bfe'
  asm='nop'
  jmp=0xaddr
  c='void func() { int a; a = 1; }' (only supported on inject, not patch)

/Applications/IDA\ Pro\ 6.8/idaq.app/Contents/MacOS/idaq64 -A -Sida/allfuncs.py a.out