Question

我正在尝试在我的python脚本中获取以下shell命令的输出，

hadoop fs -ls /projectpath/ | grep ^d | grep -v done | head -1 | awk {'print $8'}

我可以通过os.popen成功获取输出，如下所示：

import os
cmd = "hadoop fs -ls /projectpath/ | grep ^d | grep -v done | head -1 | awk {'print $8'}"
p = os.popen(cmd,"r")
while 1:
    line = p.readline()
    if not line: break
    print line

但是自{python 2.6}以来已弃用os.popen()所以我想用subprocess.Popen()函数替换上面的代码段。

但下面subprocess.Popen()的代码段提供的结果与上面的代码段不同。

import subprocess as sub
import shlex
cmd = "hadoop fs -ls /projectpath/ | grep ^d | grep -v done | head -1 | awk {'print $8'}"
args = shlex.split(cmd)
p = sub.Popen(args,stdout=sub.PIPE,stderr=sub.PIPE)
output, errors = p.communicate()
print output

上面的命令只给出命令'hadoop fs -ls /projectpath/'部分的输出。我曾尝试为subpocess.Popen()查询多个引用（http://docs.python.org/2/library/subprocess.html#popen-objects，Python, os.system for command-line call (linux) not returning what it should?），但无法在字符串cmd中执行该命令。谁能指出我做错了什么？

Answer 1

试试这个：

cmd = "hadoop fs -ls /projectpath/ | grep ^d | grep -v done | head -1 | awk {'print $8'}"
p = sub.Popen(cmd,stdout=sub.PIPE,stderr=sub.PIPE, shell=True)

python subprocess.Popen vs os.popen

1 个答案: