如何使用 Python 将命令提示符中的命令写入文件？

Question

本质上，我想创建一个具有多种选择的脚本来检查主机名上的某些数据。例如，这里的代码可以选择在给定的主机名上 ping 或运行tracert。

import os

print("""What did you want to run? (pick a number)
        (1) Ping
        (2) Traceroute""")

runit = raw_input("> ")

print ("Enter a hostname to check")
host = raw_input("> ") #accept input for hostname

if runit == "1":
    os.system("cmd /c ping " + host) 
elif runit == "2":
    os.system("cmd /c tracert " + host)

上面的代码有效，我可以得到结果并手动复制它们，但我希望这能自动完成。我知道我可以使用类似

的方式打开文件

p = open("ping1.txt", "w")

但我不确定如何从命令提示符复制跟踪或 ping 的结果？任何帮助将不胜感激。

Answer 1

您可以使用subprocess.Popen 查看输出并写入文件：

from subprocess import Popen, PIPE
print("""What did you want to run? (pick a number)
        (1) Ping
        (2) Traceroute""")

runit = raw_input("> ")

print ("Enter a hostname to check")
host = raw_input("> ") #accept input for hostname

if runit == "1":
    p  = Popen("cmd /c ping " + host, shell=True, stdout=PIPE)
    with open("ping.txt","w") as f:
        for line in iter(p.stdout.readline,""):
            print(line)
            f.write(line)

elif runit == "2":
     p = Popen("cmd /c tracert " + host, shell=True, stdout=PIPE)
     with open("trace.txt", "w") as f:
         for line in iter(p.stdout.readline, ""):
             print(line)
             f.write(line)

为了保持代码干爽并允许用户在选择错误的选项时再次选择，您可以使用带有 str.format 的 while 循环和 dict 来保留选项：

from subprocess import Popen, PIPE

opts = {"1": "ping", "2": "tracert"}

while True:
    print("""What did you want to run? (pick a number)
            (1) Ping
            (2) Traceroute""")
    runit = raw_input("> ")
    if runit in opts:
        host = raw_input("Enter a hostname to check\n> ")  # accept input for hostname
        p = Popen("cmd /c {} {}".format(opts[runit], host), shell=True, stdout=PIPE)
        with open("ping.txt", "w") as f:
            for line in iter(p.stdout.readline, ""):
                print(line)
                f.write(line)
        break
    print("Invalid option")

Answer 2

os.system(command) 在子 shell 中执行命令并在大多数系统上返回其退出状态（至少对于 cmd.exe）。

subprocess 模块非常适合做更多的事情。

您可能想要使用subprocess.check_output，它使用参数运行命令并将其输出作为字节字符串返回。

subprocess.check_output(args, *, stdin=None, stderr=None, shell=False, universal_newlines=False)`

Answer 3

要将命令的输出重定向到文件，您可以将stdout 参数传递给subprocess.check_call()：

#!/usr/bin/env python2
import subprocess

one_or_two = raw_input("""What did you want to run? (pick a number)
        (1) Ping
        (2) Traceroute
> """)
command = ["", "ping", "tracert"][int(one_or_two)]
host = raw_input("Enter a hostname to check\n> ") 

with open('output.txt', 'wb', 0) as file:
    subprocess.check_call([command, host], stdout=file)

如果除了将输出复制到文件之外，还想在控制台中显示输出，请参阅Displaying subprocess output to stdout and redirecting it。