Linux Powershell $PROFILE

One of my favorite things in Windows Powershell is the $PROFILE. I always refer to the How-To Geek article for creating it.

But what about $PROFILE in Linux Powershell?

PS /home/david> Test-Path $PROFILE
False
PS /home/david> New-Item -Path $PROFILE -Type File -Force

    Directory: /home/david/.config/powershell

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
------          3/29/19  10:26 AM              0 Microsoft.PowerShell_profile.ps1

PS /home/david> $PROFILE
/home/david/.config/powershell/Microsoft.PowerShell_profile.ps1


That was easy, but what do we do with this?

Well, for one thing, I notice that my terminal while in Powershell is named "Untitled".

That's an easy fix:

PS /home/david> Set-Content -Path $PROFILE -Value '$Host.UI.RawUI.WindowTitle = "Powershell"'
PS /home/david> Get-Content $PROFILE
$Host.UI.RawUI.WindowTitle = "Powershell"
PS /home/david> .$PROFILE

Now it looks like a shell should:

You could also add a function, allowing you to rename the terminal on demand. Add to your $PROFILE in an editor:

function Rename-Shell{
    param([string]$Name)
    $Host.UI.RawUI.WindowTitle = $Name
}


Then reload your $PROFILE and add a new title:

PS /home/david> .$PROFILE
PS /home/david> Rename-Shell -Name 'My Terminal'


Your  $PROFILE loads every time you start Powershell and imports the contents. If you change the $PROFILE you can reload it by "dot sourcing" (the .$PROFILE mentioned above). You can set variables, create functions, assign aliases... $PROFILE is a Powershell script, so if you can script it, you can add it.

Linux Powershell Issues: History

So, my Mint system has Powershell. "Let's see how it works," I say.

david@mint ~ $ powershell
PowerShell 6.1.3

https://aka.ms/pscore6-docs
Type 'help' to get help.

PS /home/david> Get-Location
Error reading or writing history file '/home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt': Access to the path '/home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt' is denied.
ưm
Path
----
/home/david


Well, that's no good. It ran the Get-Location command, but I certainly don't want to see all that red every time I perform an action in the shell. Fortunately, the error shows us where our history file is.

david@mint ~ $ ls -l /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt
-rw-r--r-- 1 root root 336 Mar 28 11:04 /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt


Why does root own my history file? I installed Powershell as root, but that still seems odd. Well, there's no going back, so let's take over the file.

david@mint ~ $ sudo chown david /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt
[sudo] password for david:
david@mint ~ $ sudo chgrp david /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt
david@mint ~ $ ls -l /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt
-rw-r--r-- 1 david david 336 Mar 28 11:04 /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt


Now, back to the shell:

david@mint ~ $ powershell
PowerShell 6.1.3
Copyright (c) Microsoft Corporation. All rights reserved.

https://aka.ms/pscore6-docs
Type 'help' to get help.

PS /home/david> Get-Location

Path
----
/home/david

PS /home/david> Get-History

  Id CommandLine
  -- -----------
   1 Get-Location

Sha-Bang Your Scripts

Sometimes, Windows can be a friendly scripting environment. You write a batch file, and you run it. You write a Powershell script, and provided your Execution Policy allows it, you run it. If it is a batch file, you can even double-click it in the GUI. Powershell, however, you either need to run in its shell, or wrap it in a batch script. The bash shell works a bit differently.

The Sha-Bang (Sharp Bang) declares to the shell what is needed to execute the script. A bash script (example.sh) would normally look like:

#!/bin/sh
echo "Hello, World!"


You would then add the executable flag:

chmod +x example.sh

The same can be done with other interpreters, such as python or perl:

#!/usr/bin/env python
print("Hello, World!")


Or:

#!/usr/bin/perl -w
print "Hello, World!\n"


The same can be done with Powershell on linux, provided your shell knows where Powershell lives.

$ which powershell
/snap/bin/powershell


If you get a response, then Powershell is in your env PATH, so you can have:

#!/usr/bin/env powershell
Write-Host "Hello, World!"


Powershell users in Windows will note that just as running a local script, you need a dot-slash:

$ ./example.ps1
Hello, World!