buffer_len.py

import sys

target = sys.argv[1]

for i in range(1, 256):
    try:
        buffer = "A" * i
        payload = buffer + target
        print("[+] Trying buffer length: %d" % i)
        response = subprocess.check_output(payload, shell=True)
    except:
        print("[+] Buffer length found: %d" % i)
        break