使用&&在subprocess.Popen中进行命令链接?

时间:2013-03-17 22:51:12

标签: python linux python-2.7 popen chaining

我正在subprocess.Popen使用Python,我没有遇到通过&&加入命令(即foobar Popen bizbang)的优雅解决方案。< / p>

我可以这样做:

p1 = subprocess.Popen(["mmls", "WinXP.E01"], stdout=subprocess.PIPE)
result = p1.communicate()[0].split("\n")
for line in result:
    script_log.write(line)

script_log.write("\n")

p1 = subprocess.Popen(["stat", "WinXP.E01"], stdout=subprocess.PIPE)
result = p1.communicate()[0].split("\n")
for line in result:
    script_log.write(line)

但这真的不太美观(特别是如果我通过Popen菊花链式连接多个命令。


我想在尽可能少的命令块中复制此输出。

not@work ~/ESI/lab3/images $ mmls WinXP.E01 && echo -e "\n" && stat WinXP.E01
DOS Partition Table
Offset Sector: 0
Units are in 512-byte sectors

     Slot    Start        End          Length       Description
00:  Meta    0000000000   0000000000   0000000001   Primary Table (#0)
01:  -----   0000000000   0000000062   0000000063   Unallocated
02:  00:00   0000000063   0020948759   0020948697   NTFS (0x07)
03:  -----   0020948760   0020971519   0000022760   Unallocated


  File: `WinXP.E01'
  Size: 4665518381  Blocks: 9112368    IO Block: 4096   regular file
Device: 14h/20d Inode: 4195953     Links: 1
Access: (0644/-rw-r--r--)  Uid: ( 1000/    nott)   Gid: ( 1000/    nott)
Access: 2013-03-16 23:20:41.901326579 -0400
Modify: 2013-03-04 10:05:50.000000000 -0500
Change: 2013-03-13 00:25:33.254684050 -0400
 Birth: -

有什么建议吗?

注意:我希望避免在subprocess.Popen

中输入此内容
p1 = subprocess.Popen(["mmls WinXP.E01 && echo -e '\n' && stat WinXP.E01"], stdout=subprocess.PIPE)

2 个答案:

答案 0 :(得分:4)

&安培;&安培;是一个shell操作符,POpen默认不使用shell。

如果你想使用shell功能,请在你的POpen调用中使用shell = True,但要注意它稍慢/内存密集。

p1 = subprocess.Popen(["mmls", "WinXP.E01", "&&", "echo", "-e", "\"\n\"", "&&", "stat", "WinXP.E01"],
                      stdout=subprocess.PIPE, shell=True)

答案 1 :(得分:1)

这个怎么样:

from subprocess import Popen, PIPE

def log_command_outputs(commands):
    processes = [Popen(cmd, stdout=PIPE) for cmd in commands]
    outputs = [proc.communicate()[0].split() for proc in processes]
    for output in outputs:
        for line in output:
            script_log.write(line)
        script_long.write("\n")

这会并行启动命令,这可能会比逐个执行命令(但可能不是很大)。由于communicate调用是顺序的,所以任何具有大输出(超过管道缓冲区)的命令都将阻塞,直到它被清理为止。

对于您的示例命令链,您可以调用:

log_command_outputs([["mmls", "WinXP.E01"], ["stat", "WinXP.E01"]])