Python running as Windows Service: OSError: [WinError 6] The handle is invalid
python, subprocess, windows
Solution
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)
Problem
I have a Python script, which is running as a Windows Service. The script forks another process with: ``` with subprocess.Popen( args=[self.exec_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT) as proc: ``` which causes the following error: ``` OSError: [WinError 6] The handle is invalid File "C:\Program Files (x86)\Python35-32\lib\subprocess.py", line 911, in __init__ File "C:\Program Files (x86)\Python35-32\lib\subprocess.py", line 1117, in _get_handles ```