Run Powershell script results in `The command line is too long.`

I’m trying to run a .ps1 script on a remote machine and it just throws an error saying “The command line is too long.” My python code is:

import winrm
myScriptSource = open('script.ps1', 'r').read()
session = winrm.Session('myHost', auth=('myUser','myPass'))
result = session.run_ps(myScriptSource)
print(result)

The script.ps1 has 70 lines and runs fine on Powershell.

[killjoy1221]

This is caused by cmd having a length limit of ~8K. You can get around this by using low-level api and sneaking the script into an environment variable, which afaik has a much higher limit.

Update 11/4/2020

This should be considered a temporary solution. Windows has a shared pool of 2^15 characters for all environment variables, so this won’t work for all scripts. A better solution is mentioned here

Original solution

import winrm
from base64 import b64encode

script = """
# Really long script >8kb goes here
"""
cmd = """
# Load script from env-vars
. ([ScriptBlock]::Create($Env:WINRM_SCRIPT))
"""
encoded_cmd = b64encode(cmd.encode('utf_16_le')).decode('ascii')

p = winrm.protocol.Protocol(url, username="user", password="secret")

# Load script to env vars.
shell = p.open_shell(env_vars=dict(WINRM_SCRIPT=script)
command = p.run_command(shell, "powershell -EncodedCommand {}".format(encoded_cmd))

rs = winrm.Response(p.get_command_output(shell, command)

p.cleanup_command(shell, command)
p.close_shell(shell)

print(str(rs.std_out, 'ascii'))

[jborean93]

Duplicate of https://github.com/diyan/pywinrm/issues/87.