What commands are avaible on a Windows container? Can I run the "DIR" command?

No. You can not run the "DIR" command on a Windows container directly, because "DIR" is not really a Windows command. "DIR" is actually sub-command valid in the "CMD" shell environment.

On a Windows container, you can only commands supported with executable files located in the PATH directorires, or commands with path name specified in the command line.

1. Try to run "DIR" command on "microsoft/dotnet-samples". It will not work, because there is no program file to support this command.

C:\fyicenter> docker run --name windows --entrypoint dir microsoft/dotnet-samples

docker: Error response from daemon: container 73e94dac1ea3 encountered
an error during CreateProcess: failure in a Windows system call:
The system cannot find the file specified. (0x2) extra info:
{"CommandLine":"dir","WorkingDirectory":"C:\\app","Environment":{"ASP
NETCORE_URLS":"http://+:80","DOTNET_RUNNING_IN_CONTAINER":"true","DOT
NET_VERSION":"2.2.2"},"CreateStdInPipe":true,"CreateStdOutPipe":true,
"CreateStdErrPipe":true,"ConsoleSize":[0,0]}.

C:\fyicenter> docker rm windows
windows

2. Try to run "powershell" command. It will work, because the powershell.exe program file can be located in PATH directories.

C:\fyicenter> docker run --name windows --entrypoint powershell microsoft/dotnet-samples
Windows PowerShell
Copyright (C) 2016 Microsoft Corporation. All rights reserved.

PS C:\app>

C:\fyicenter> docker rm windows

3. Try to run "\windows\system32\cmd.exe" with path name specified. It will work, because the given path does exist on the image:

C:\fyicenter> docker run --name windows --entrypoint \windows\system32\cmd.exe
   microsoft/dotnet-samples

Microsoft Windows [Version 10.0.14393]
(c) 2016 Microsoft Corporation. All rights reserved.

C:\app>

C:\fyicenter> docker rm windows

Ok, we are able to run executable programs on the Docker image, with path name specified or not specified if they can be located in PATH directories.

See next tutorial on how to find out PATH directories of the Windows image.

⇒ PATH Directories of Windows Container

⇐ "docker run --entrypoint" - Override Default Command

⇑ Building Docker Images for Windows

⇑⇑ Docker Container Platform - Tutorials