subprocess.run不抑制所有控制台输出

Posted 2021-05-07

[subprocess.run与stdout=DEVNULL和stderr=STDOUT并不会抑制subinacl.exe实用程序的所有输出。

>>> # Do not suppress: OK
>>> subprocess.run('subinacl.exe /service "foo" display', shell=True)
foo - OpenService Error : 1060 The specified service does not exist as an installed service.



Elapsed Time: 00 00:00:00
Done:        1, Modified        0, Failed        1, Syntax errors        0
Last Done  : foo
Last Failed: foo - OpenService Error : 1060 The specified service does not exist as an installed service.

CompletedProcess(args='subinacl.exe /service "foo" display', returncode=0)

>>> # Suppress: Some output is still printed
>>> subprocess.run('subinacl.exe /service "foo" display', shell=True, stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT)

Elapsed Time: 00 00:00:00
Done:        1, Modified        0, Failed        1, Syntax errors        0
Last Done  : foo
Last Failed: foo - OpenService Error : 1060 The specified service does not exist as an installed service.

CompletedProcess(args='subinacl.exe /service "foo" display', returncode=0)
>>>

我的猜测是subinacl.exe正在调用另一个进程，该进程打印未抑制的输出。 stdout=DEVNULL和stderr=STDOUT不会使整个过程链的输出静音吗？

答案

基于Sun的评论，我不得不使用

subprocess.run(
    'subinacl.exe /service "foo" display',
    stdout=subprocess.DEVNULL,
    stderr=subprocess.STDOUT, 
    creationflags=subprocess.CREATE_NO_WINDOW
)