Argparse 或 sys.argv - 检查不正确的 CLI 参数

如何解决Argparse 或 sys.argv - 检查不正确的 CLI 参数

如何使用 argparse 或 sys.argv 检查 CLI 参数是否输入错误，然后打印某些内容？

参数是：

--remote_host google.com --verbose 0（或verbose 1 表示完整详细信息...）

或

--帮助

#!/usr/bin/env python

import logging
logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
import argparse
import sys
from scapy.all import *

parser = argparse.ArgumentParser(add_help=False)
parser.add_argument("--remote_host")
parser.add_argument("--verbose")
parser.add_argument("--help",action='store_true')
args = parser.parse_args()

if args.help:
    print("Custom Help Section...")
    exit()
 
# Define end host and TCP port range
hostInput    = args.remote_host
host  = socket.gethostbyname(hostInput)
port_range = [21,22,23,25,53,80,110,135,137,138,139,443,1433,1434,8080]

# Send SYN with random Src Port for each Dst port
for dst_port in port_range:
    src_port = random.randint(1025,65534)
    resp = sr1(
        IP(dst=host)/TCP(sport=src_port,dport=dst_port,flags="S"),timeout=1,verbose=int(args.verbose),)

    if resp is None:
        print(f"{host}:{dst_port} is filtered (silently dropped).")

    elif(resp.haslayer(TCP)):
        if(resp.getlayer(TCP).flags == 0x12):
            # Send a gratuitous RST to close the connection
            send_rst = sr(
                IP(dst=host)/TCP(sport=src_port,flags='R'),)
            print(f"{host}:{dst_port} is open.")

        elif (resp.getlayer(TCP).flags == 0x14):
            print(f"{host}:{dst_port} is closed.")

    elif(resp.haslayer(ICMP)):
        if(
            int(resp.getlayer(ICMP).type) == 3 and
            int(resp.getlayer(ICMP).code) in [1,2,3,9,10,13]
        ):
            print(f"{host}:{dst_port} is filtered (silently dropped).")

解决方法

您可以简单地使用以下命令获取所有 CLI 参数：

arglist = sys.argv[1:]  # first parameter is always script name

然后，您可以对可用命令列表进行检查，例如：

available_commands = ['--help','--remote_host','google.com','--verbose','0','1']
for arg in arglist:
    valid = False
    for command in available_commands:
        if arg == command: valid = True
    if not valid:
        raise ValueError('Invalid command name')