Python Running as Windows Service: Oserror: [Winerror 6] the Handle Is Invalid

Python running as Windows Service: OSError: [WinError 6] The handle is invalid

Line 1117 in subprocess.py is:

p2cread = _winapi.GetStdHandle(_winapi.STD_INPUT_HANDLE)

which made me suspect that service processes do not have a STDIN associated with them (TBC)

This troublesome code can be avoided by supplying a file or null device as the stdin argument to popen.

In Python 3.x, you can simply pass stdin=subprocess.DEVNULL. E.g.

subprocess.Popen( args=[self.exec_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, stdin=subprocess.DEVNULL)

In Python 2.x, you need to get a filehandler to null, then pass that to popen:

devnull = open(os.devnull, 'wb')
subprocess.Popen( args=[self.exec_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, stdin=devnull)

pyinstaller error: OSError: [WinError 6] The handle is invalid

This error apparently is thrown, because of this:

Line 1117 in subprocess.py is: p2cread = _winapi.GetStdHandle(_winapi.STD_INPUT_HANDLE)

The service processes do not have a STDIN associated with them (TBC).

This problem can be avoided by supplying a file or null device as the stdin argument to popen.

In Python 3.x, you can simply pass stdin=subprocess.DEVNULL.
E.g.

subprocess.Popen( args=[self.exec_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, stdin=subprocess.DEVNULL)

In Python 2.x, you need to get a filehandler to null, then pass
that to popen:

devnull = open(os.devnull, 'wb')
subprocess.Popen( args=[self.exec_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, stdin=devnull)  

Reference: OSError: (WinError 6) The handle is Invalid

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In your problem:

subprocess.run(["netsh", "wlan", "show", "profiles"], capture_output = True, stdin=subprocess.DEVNULL).stdout.decode()

WinError 6: The handle is invalid from python check_output spawn in Electron app

On Windows, subprocess.Popen tries to duplicate non-zero standard handles and fails if they're invalid. You can redirect stdin and stderr to NUL. For example:

import os

try:
    from subprocess import DEVNULL
except ImportError:
    DEVNULL = os.open(os.devnull, os.O_RDWR)

output = subprocess.check_output(cmd, stdin=DEVNULL, stderr=DEVNULL)

WinError 6 - The handle is invalid with executable but code works on debug mode

The problem is with psa1_path variable

C:/Users/${USERNAME}\projects\demo\cmd\powershell.ps1 -m -v 'CC 2018' -wait windowstyle hidden

This variable has parameters. And the subprocess.Popen use it as a string, then you have to set shell=True so Popen will use this string as a complete shell cmd.

p = subprocess.Popen(['C:\\WINDOWS\\system32\\WindowsPowerShell\\v1.0\\powershell.exe',
                              '-ExecutionPolicy',
                              'Unrestricted',
                              psa1_path],
                             stdout=f, shell=True, stdin=subprocess.DEVNULL)

Don't forget to add stdin arg because it's also throw the [WinError 6] The handle is invalid

So why the code works with debug code and not with executable :

It's mainly because PyCharm does additionnal configuration and setup behind the scenes when it comes to running a program.

Because when you’re going from IDE to runtime, you need additional hooks to get things going. pyinstaller doesn’t do the subprocess the same way as pyCharm for the shell part

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