从python运行linux命令 [英] Running a linux command from python

问题描述

我需要从python运行此linux命令，并将输出分配给变量.

I need to run this linux command from python and assign the output to a variable.

ps -ef | grep rtptransmit | grep -v grep

我尝试使用pythons命令库执行此操作.

I've tried using pythons commands library to do this.

import commands
a = commands.getoutput('ps -ef | grep rtptransmit | grep -v grep')

但是a结束了.我得到的输出是:

But a gets the end of cut off. The output I get is:

'nvr      20714 20711  0 10:39 ?        00:00:00 /opt/americandynamics/venvr/bin/rtptransmit setup_req db=media  camera=6  stream=video  substream=1  client_a'

但预期的输出是:

nvr      20714 20711  0 10:39 ?        00:00:00 /opt/americandynamics/venvr/bin/rtptransmit setup_req db=media  camera=6  stream=video  substream=1  client_address=192.168.200.179  client_rtp_port=6970  override_lockout=1  clienttype=1

有人知道如何阻止输出中断吗?有人可以建议其他方法吗?

Does anyone know how to stop the output from getting cut off or can anyone suggest another method?

推荐答案

ps显然限制了其输出以适合终端的假定宽度.您可以使用$COLUMNS环境变量或ps的--columns选项覆盖此宽度.

ps apparently limits its output to fit into the presumed width of the terminal. You can override this width with the $COLUMNS environment variable or with the --columns option to ps.

不推荐使用commands模块.使用subprocess获取ps -ef的输出，并在Python中过滤输出.请勿使用其他答案建议的shell=True，在这种情况下，它只是多余的:

The commands module is deprecated. Use subprocess to get the output of ps -ef and filter the output in Python. Do not use shell=True as suggested by other answers, it is simply superfluous in this case:

ps = subprocess.Popen(['ps', '-ef', '--columns', '1000'], stdout=subprocess.PIPE)
output = ps.communicate()[0]
for line in output.splitlines():
    if 'rtptransmit' in line:
        print(line)

您可能还想看看pgrep命令，通过它可以直接搜索特定进程.

You may also want to take a look the pgrep command by which you can directly search for specific processes.

这篇关于从python运行linux命令的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！