My PowerShell Profile

Moving from Zsh, which is easily configurable by Oh My Zsh, the PowerShell on Windows always feels pitiably basic. PowerShell does not enjoy the privilege of Oh My Zsh, unfortunately. Although there is a Oh My Posh project that claims to be inspired by Oh My Zsh, it is, in my mind, overly fancy.

In this note, we try to custom PowerShell with a very simple PowerShell profile. It will allow your PowerShell to mimic your favorite shell’s behavior, at least to some extent.

PowerShell’s profile

The .bashrc’s equivalent in PowerShell is called profile, stored at $PROFILE. PowerShell will load this script upon startup.

To open this file with Notepad, open a PowerShell window and enter the following command:

notepad.exe $PROFILE

If its parent folder does not exist, you might need to create the parent folder to be able to save this file. Edit, and save this file, and start a new PowerShell window, you will see the changes taking effect.

PowerShell’s execution policy

If you have not changed the execution policy, the loading of your PowerShell’s profile might be blocked because of the execution policy. You can change it by

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser 

Please refer to PowerShell’s official document Set-ExecutionPolicy for a more detailed description of this command.

Command prompt

I like Oh My Zsh’s candy theme. Here is how to recreate this prompt in PowerShell in a very basic form.

function Prompt {
    $Time = Get-Date -UFormat %H:%M:%S
    Write-Host "$env:USERNAME@$env:COMPUTERNAME " -ForegroundColor Green -NoNewline
    Write-Host "[$Time] " -ForegroundColor Blue -NoNewline
    Write-Host "[$pwd]"
    Write-Host "-> %" -ForegroundColor Blue -NoNewline
    return " "
}

Tab completion

Here is how to mimic bash and zsh’s tab autocompletion behavior.

Set-PSReadlineKeyHandler -Key Tab -Function Complete

OpenSSH Server

Install the OpenSSH server by enable it in Windows Settings’s Optional Features, then start the “OpenSSH Server” (sshd) service and set its startup type to “Automatic”.

Set Powershell as the login shell

According to OpenSSH Server configuration for Windows:

New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShell -Value "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -PropertyType String -Force

Public-private key authorization

See Setting up OpenSSH for Windows using public key authentication - Stack Overflow. The caveats are:

• The full sshd configuration file is located at C:\ProgramData\ssh\sshd_config.
• All the authorized_keys files needs to have proper permission setting, i.e., no permission inheritance, only the relevant user and SYSTEM user have access to it. For users, it is the .ssh/authorized_keys, for the Administratror group, it is the __PROGRAMDATA__/ssh/administrators_authorized_keys file, these are defined in the sshd_config.
• You need to restart the sshd service to apply the changes in sshd_config.

Package manager & coreutils

For CLI tools, use Scoop (compared to Chocolatey, aka choco, Scoop is more focused on CLI tools).

Install scoop via the following command:

Invoke-WebRequest get.scoop.sh | Invoke-Expression

Then install the coreutils, vim, etc.:

scoop install coreutils vim # ...