子进程运行命令直到第一个管道，然后停止

Question

如果我运行这个命令本身：

nmap -PN -p 22 --open -oG - 10.15.86.0/24 | awk '$NF~/ssh/{print}' > sshopen.txt

我收到了我想要的输出：

10.15.86.4
10.15.86.5
10.15.86.9
10.15.86.11
etc...

我网络上的所有主机都打开了 ssh 端口。但是，当我尝试在 Python 子进程中运行相同的命令时，它似乎跳过了 awk。 Python 以下：

import subprocess

subnet = raw_input("Enter subnet to scan: ")
command1 = "nmap -PN -p 22 --open -oG - 10.15.86.0/24 | awk '$NF~/ssh /{print}' > sshopen.txt".split()
#command = ["nmap", "-PN", "-p", "22", "--open", "-oG", "-", subnet, "|", "awk", "'$NF~/ssh/{print }'", ">", "sshopen.txt"]
nmap = subprocess.Popen(command1, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
nmap_info, out = nmap.communicate()  
print nmap_info

您会注意到注释 'command'，因为我已尝试使用 'command' 和 'command1'。 return 输出：

Host: 10.15.86.4 () Status: Up
Host: 10.15.86.4 () Ports: 22/open/tcp//ssh///
Host: 10.15.86.5 () Status: Up
Host: 10.15.86.5 () Ports: 22/open/tcp//ssh///
etc...

它输出好像没有管道 awk (nmap -PN -p 22 --open -oG - 10.15.86.0/24) 而不是 (nmap -PN -p 22 --open -oG - 10.15。 86.0/24 | awk '$NF~/ssh/{print$2}' > sshopen.txt)。为什么不在脚本中应用 awk？

谢谢

Answer 1

尝试

p1 = Popen(["nmap", "-PN", "-p", "22", "--open", "-oG", "-", subnet], stdout=PIPE)
p2 = Popen(["awk", "$NF~/ssh/{print}"], stdin=p1.stdout, stdout=PIPE)
p1.stdout.close()
output = p2.communicate()[0]

或

check_output(command, shell=True)

来自python的官方subprocess doc.

虽然有一些 security considerations shell=True。

Unlike some other popen functions, this implementation will never implicitly call a system shell. This means that all characters, including shell metacharacters, can safely be passed to child processes. If the shell is invoked explicitly, via shell=True, it is the application’s responsibility to ensure that all whitespace and metacharacters are quoted appropriately to avoid shell injection vulnerabilities.

子进程运行命令直到第一个管道，然后停止

subprocess runs command up to first pipe, then stops

python

awk

subprocess

nmap