我知道如何使用cmd = subprocess.Popen和subprocess.communicate運行命令。大多數情況下，我將使用shlex.split標記的字符串用作Popen的'argv'參數?！?ls -l”的示例：import subprocessimport shlexprint subprocess.Popen(shlex.split(r'ls -l'), stdin = subprocess.PIPE, stdout = subprocess.PIPE, stderr = subprocess.PIPE).communicate()[0]但是，管道似乎不起作用...例如，以下示例返回注釋：import subprocessimport shlexprint subprocess.Popen(shlex.split(r'ls -l | sed "s/a/b/g"'), stdin = subprocess.PIPE, stdout = subprocess.PIPE, stderr = subprocess.PIPE).communicate()[0]你能告訴我我做錯了嗎？謝謝
3 回答
LEATH
TA貢獻1936條經驗 獲得超7個贊
我認為您想在此處實例化兩個單獨的Popen對象，一個用于“ ls”，另一個用于“ sed”。您需要將第一個Popen對象的stdout屬性作為stdin參數傳遞給第二個Popen對象。
例：
p1 = subprocess.Popen('ls ...', stdout=subprocess.PIPE)
p2 = subprocess.Popen('sed ...', stdin=p1.stdout, stdout=subprocess.PIPE)
print p2.communicate()
如果您有更多命令，則可以保持鏈接的方式：
p3 = subprocess.Popen('prog', stdin=p2.stdout, ...)
請參閱子流程文檔以獲取有關如何使用子流程的更多信息。
長風秋雁
TA貢獻1757條經驗 獲得超7個贊
我已經做了一些功能來幫助管道，希望對您有所幫助。它將根據需要鏈接Popens。
from subprocess import Popen, PIPE
import shlex
def run(cmd):
"""Runs the given command locally and returns the output, err and exit_code."""
if "|" in cmd:
cmd_parts = cmd.split('|')
else:
cmd_parts = []
cmd_parts.append(cmd)
i = 0
p = {}
for cmd_part in cmd_parts:
cmd_part = cmd_part.strip()
if i == 0:
p[i]=Popen(shlex.split(cmd_part),stdin=None, stdout=PIPE, stderr=PIPE)
else:
p[i]=Popen(shlex.split(cmd_part),stdin=p[i-1].stdout, stdout=PIPE, stderr=PIPE)
i = i +1
(output, err) = p[i-1].communicate()
exit_code = p[0].wait()
return str(output), str(err), exit_code
output, err, exit_code = run("ls -lha /var/log | grep syslog | grep gz")
if exit_code != 0:
print "Output:"
print output
print "Error:"
print err
# Handle error here
else:
# Be happy :D
print output
米琪卡哇伊
TA貢獻1998條經驗 獲得超6個贊
shlex 僅根據shell規則拆分空間，但不處理管道。
但是，它應該以這種方式工作：
import subprocess
import shlex
sp_ls = subprocess.Popen(shlex.split(r'ls -l'), stdin = subprocess.PIPE, stdout = subprocess.PIPE, stderr = subprocess.PIPE)
sp_sed = subprocess.Popen(shlex.split(r'sed "s/a/b/g"'), stdin = sp_ls.stdout, stdout = subprocess.PIPE, stderr = subprocess.PIPE)
sp_ls.stdin.close() # makes it similiar to /dev/null
output = sp_ls.communicate()[0] # which makes you ignore any errors.
print output
根據help(subprocess)的
Replacing shell pipe line
-------------------------
output=`dmesg | grep hda`
==>
p1 = Popen(["dmesg"], stdout=PIPE)
p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
output = p2.communicate()[0]
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