Question

我需要在 Python 中运行以下（工作）命令：

ip route list dev eth0 | awk ' /^default/ {print $3}'

使用subprocess，我必须执行以下操作：

first = "ip route list dev eth0"
second = "awk ' /^default/ {print $3}'"
p1 = subprocess.Popen(first.split(), stdout=subprocess.PIPE)
p2 = subprocess.Popen(second.split(), stdin=p1.stdout, stdout=subprocess.PIPE)
p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
output = p2.communicate()[0]

p2出了点问题。我明白了：

>>> awk: cmd. line:1: '
awk: cmd. line:1: ^ invalid char ''' in expression

我该怎么办？在终端上它完美运行。

Answer 1

split分裂任何空格，包括单引号内的空格。如果您真的需要，请使用shlex.split：

import shlex
p2 = subprocess.Popen(shlex.split(second), stdin=p1.stdout, stdout=subprocess.PIPE)

但是直接指定命令通常更有意义：

first = ['ip', 'route', 'list', 'dev', 'eth0']
second = ['awk', ' /^default/ {print $3}']
p1 = subprocess.Popen(first, stdout=subprocess.PIPE)
p2 = subprocess.Popen(second, stdin=p1.stdout, stdout=subprocess.PIPE)

Answer 2

不是最佳解决方案，但在等待最佳答案时，您仍然可以这样做：

cmd = "ip route list dev eth0 | awk ' /^default/ {print $3}'"
p2 = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, shell=True)

来自Python的awk：错误的子进程参数？

2 个答案: