Tag Archives: prompt

Linux Prompt on Windows – Part VI

My most recent post in the Linux Prompt on Windows series, is Part V. Now, we’re on VI and it’s all because of PowerShell 6.0.

As 6.0 uses a different $PROFILE script, it was mandatory that I created a new one and quickly copied over my Linux prompt. I hate to be anywhere without it. You can create a $PROFILE script in PowerShell 6.0 the same way we did previously. It’s New-Item -Path $PROFILE -Force (press Enter) followed by notepad $PROFILE (press Enter) to open the file, in Notepad, which should be obvious.

The newest change is adding the version number, just to the right of the host program’s name in the WindowTitle. Here’s an example of how that appears. As it should the WindowTitle indicates it’s PowerShell 6.0.

Type in powershell.exe and press Enter, and the WindowTitle changes. Now we’re in PowerShell 5.1.

Go deeper in time and type powershell.exe -version 2, press Enter, and it changes again, but this time to 2.0. By adding this addition to the WindowTitle via my prompt function, I can move between versions of PowerShell, if needed, and always know the version in which I’m working.

I’ve included the fully updated prompt function below. Copy it into your $PROFILE script, restart PowerShell, and enjoy. I can’t be the only one to appreciate this prompt, especially as PowerShell 6.0 just went GA. As the beta versions before it were, it’s cross platform; therefore, my lookalike Linux prompt makes even more sense now.

Update: I recently cleaned out my new 6.0 $PROFILE script and did what I’ve always done instead. That is to dot source a different profile script (the one loaded by Windows PowerShell 5.1). So, in place of my prompt function, I now have this entry: . C:\Users\tommymaynard\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1. Yeah, you’re reading that right, “WindowsPowerShell.” All my stuff is in there! It should be fun to see what works and what doesn’t!

Update: I got really tired of looking up at the WindowTitle to see my version, so I added it to the prompt, as well. It’s just after the closing square bracket and before the # or $ symbol. By the way, the difference of those two is that # indicates an administrative user, and $ indicates a non-administrative user. Oh yes, and for today, my host is blue. It’s not the exact blue, but close. The font color is also gray (by default), another slight difference between the host configuration for 5.1 vs. 6.0. Anyway, I’ve updated the below code to indicate the version as a part of the prompt itself, just like in the below image.

Function Prompt {
	(Get-PSProvider -PSProvider FileSystem).Home = $env:USERPROFILE

	# Determine if Admin and set Symbol variable.
	If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
		$Symbol = '#'
	} Else {
		$Symbol = '$'
	}
	 
	# Write Path to Location Variable as /.../...
	If ($PWD.Path -eq $env:USERPROFILE) {
		$Location = '/~'
	} ElseIf ($PWD.Path -like "*$env:USERPROFILE*") {
		$Location = "/$($PWD.Path -replace ($env:USERPROFILE -replace '\\','\\'),'~' -replace '\\','/')"
	} Else {
		$Location = "$(($PWD.Path -replace '\\','/' -split ':')[-1])"
	}

	# Determine Host for WindowTitle.
	Switch ($Host.Name) {
		'ConsoleHost' {$HostName = 'consolehost'; break}
		'Windows PowerShell ISE Host' {$HostName = 'ise'; break}
        'Visual Studio Code Host' {$HostName = 'vscode'; break}
		default {}
	}

    # Determine PowerShell version.
    $PSVer = "$($PSVersionTable.PSVersion.Major).$($PSVersionTable.PSVersion.Minor)"

	# Create and write Prompt; Write WindowTitle.
    $UserComputer = "$($env:USERNAME.ToLower())@$($env:COMPUTERNAME.ToLower())" 
    $Location = "$((Get-Location).Drive.Name.ToLower())$Location"

    # Check if in the debugger.
    If (Test-Path -Path Variable:/PSDebugContext) {
        $DebugStart = '[DBG]: '
        $DebugEnd = ']'
    }

    # Actual prompt and title.
    $Host.UI.RawUI.WindowTitle = "$HostName $PSver`: $DebugStart[$UserComputer $Location]$DebugEnd$Symbol"
    "$DebugStart[$UserComputer $Location]$DebugEnd$PSVer$Symbol "
}

 

Linux Prompt on Windows – Part V

http://tommymaynard.com/an-addition-to-the-linux-powershell-prompt-iv-2016/

http://tommymaynard.com/an-addition-to-the-linux-powershell-prompt-ii-2016/

http://tommymaynard.com/an-addition-to-the-linux-powershell-promp-2016/

http://tommymaynard.com/duplicate-the-linux-prompt-2016/

Linux Prompt on Windows – Part V

The last time I wrote about my Linux prompt, we were on post IV. Now it’s V, and all because I’m tired of not knowing if I’m in the debugger or not. The standard PowerShell prompt, when in the debugger, will add [DBG]: to the beginning of the prompt and an extra right angle bracket to the end. Therefore, the standard PowerShell ends up looking like it does toward the bottom of this first example.

PS C:\Users\tommymaynard> Set-PSBreakpoint -Script .\Desktop\NewScript.ps1 -Line 7
ID Script                Line Command               Variable             Action
-- ------                ---- -------               --------             ------
0 NewScript.ps1            7

PS C:\Users\tommymaynard> .\Desktop\NewScript.ps1
[DBG]: PS C:\Users\tommymaynard>> q
PS C:\Users\tommymaynard>

I’ll include my entire prompt at the end of today’s post, but before we do that, let’s focus on the new part. It’s going to add these same two things to the prompt, when I’m debugging a script. If the path, Variable:/PSDebugContext exists, we can safety assume we’re in the debugger. Therefore, when we are, we’ll assign two new variables as $DebugStart and $DebugEnd.

If (Test-Path -Path Variable:/PSDebugContext) {
    $DebugStart = '[DBG]: '
    $DebugEnd = ']'
}

Again, the above If statement is stuffed between a bunch of other PowerShell that makes up the entire prompt. Before we get there, here’s an example of what my prompt looks like now when we are, and aren’t in the debugger.

[tommymaynard@server01 c/~]$ .\Desktop\NewScript.ps1
[DBG]: [tommymaynard@server01 c/~]]$ q
[tommymaynard@server01 c/~]$ 

Excellent! Now I can continue to use my own prompt function, and know when I’m in the debugger. All this, without hitting an error to remind me. In the full prompt below, we also update the WindowTitle to reflect when we’re in the debugger, too.

# Create Linux prompt.
Function Prompt {
    (Get-PSProvider -PSProvider FileSystem).Home = $env:USERPROFILE

    # Determine if Admin and set Symbol variable.
    If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
        $Symbol = '#'
    } Else {
        $Symbol = '$'
    }
	 
    # Write Path to Location Variable as /.../...
    If ($PWD.Path -eq $env:USERPROFILE) {
        $Location = '/~'
    } ElseIf ($PWD.Path -like "*$env:USERPROFILE*") {
        $Location = "/$($PWD.Path -replace ($env:USERPROFILE -replace '\\','\\'),'~' -replace '\\','/')"
    } Else {
        $Location = "$(($PWD.Path -replace '\\','/' -split ':')[-1])"
    }

    # Determine Host for WindowTitle.
    Switch ($Host.Name) {
        'ConsoleHost' {$HostName = 'consolehost'; break}
        'Windows PowerShell ISE Host' {$HostName = 'ise'; break}
        default {}
    }

    # Create and write Prompt; Write WindowTitle.
    $UserComputer = "$($env:USERNAME.ToLower())@$($env:COMPUTERNAME.ToLower())" 
    $Location = "$((Get-Location).Drive.Name.ToLower())$Location"

    # Check if in the debugger.
    If (Test-Path -Path Variable:/PSDebugContext) {
        $DebugStart = '[DBG]: '
        $DebugEnd = ']'
    }

    # Actual prompt and title.
    $Host.UI.RawUI.WindowTitle = "$HostName`: $DebugStart[$UserComputer $Location]$DebugEnd$Symbol"
    "$DebugStart[$UserComputer $Location]$DebugEnd$Symbol "
}

Linux Prompt on Windows – Part IV

Sometime ago I wrote a Linux lookalike prompt. Since then, I’ve continued to modify it as I decided it needed changes. Today, I have a newer version, so I figured I should drop it here, as I have previously.

The difference in this version is that it adds a / between the c (C:\ drive) and ~ when I’m in my “C:\users\tommymaynard” directory, or somewhere further nested in this directory. So yeah, as of today, Monday, September 19, 2016, this is the newest version.

So you can see it before you buy it — it’s actually free — here’s a few examples of what the prompt will look like based on your location within the file system. It updates the ConsoleHost and ISE’s Window Title, too. Bonus.

# C drive: C:\
[tommymaynard@testsrv01 c/]$ 


# WSMan drive: WSMan:\
[tommymaynard@testsrv01 wsman/]$


# WSMan localhost: WSMan:\localhost
[tommymaynard@testsrv01 wsman/localhost]$


# Users folder: C:\Users
[tommymaynard@testsrv01 c/users]$ 


# Profile folder: C:\Users\tommymaynard
[tommymaynard@testsrv01 c/~]$ 


# Desktop folder: C:\Users\tommymaynard\Desktop
[tommymaynard@testsrv01 c/~/Desktop]$ 


# ProgramData folder: C:\ProgramData
[tommymaynard@testsrv01 c/ProgramData]$ 

And, here’s the prompt function.

Function Prompt {
	(Get-PSProvider -PSProvider FileSystem).Home = $env:USERPROFILE

	# Determine if Admin and set Symbol variable.
	If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
		$Symbol = '#'
	} Else {
		$Symbol = '$'
	}
	 
	# Write Path to Location Variable as /.../...
	If ($PWD.Path -eq $env:USERPROFILE) {
		$Location = '/~'
	} ElseIf ($PWD.Path -like "*$env:USERPROFILE*") {
		$Location = "/$($PWD.Path -replace ($env:USERPROFILE -replace '\\','\\'),'~' -replace '\\','/')"
	} Else {
		$Location = "$(($PWD.Path -replace '\\','/' -split ':')[-1])"
	}

	# Determine Host for WindowTitle.
	Switch ($Host.Name) {
		'ConsoleHost' {$HostName = 'ConsoleHost'; break}
		'Windows PowerShell ISE Host' {$HostName = 'ISE'; break}
		default {}
	}

	# Create and write Prompt; Write WindowTitle.
	$Prompt = "[$($env:USERNAME.ToLower())@$($env:COMPUTERNAME.ToLower()) $((Get-Location).Drive.Name.ToLower())$Location]$Symbol"
	$Host.UI.RawUI.WindowTitle = "$HostName`: $Prompt"
	
	"$Prompt "
}

Here are the previous posts on this topic:

http://tommymaynard.com/quick-learn-duplicate-the-linux-prompt-2016/
http://tommymaynard.com/quick-learn-an-addition-to-the-linux-powershell-promp-2016/
http://tommymaynard.com/quick-learn-an-addition-to-the-linux-powershell-prompt-ii-2016/

Update: There’s a part V (five) now. This includes an update to indicate when you’re in debug mode.

Linux Prompt on Windows – Part III

Maybe, just maybe, there’s someone else using my “Linux” prompt. Just in case there is, I thought to share the most recent additions. Here’s the first two posts in order, if you’re interested in reading those: Quick Learn – Duplicate the Linux Prompt and Quick Learn – An Addition to the Linux PowerShell Prompt.

The changes are extremely minor. It now includes the drive in the WindowTitle. There was never an indication of what drive you were on (C:\, AD:\, WSMan:\, Env:\, etc.). I’ve also wrapped the prompt inside square brackets. I didn’t do this initially because I didn’t want it to interfere with the way the prompt changes when inside an interactive PS Remoting session. I’m over that; it works just fine. Anyway, the code is below for your testing pleasures. Dump it in your profile to keep it around for good.

If you have questions why I’ve done certain things, then you might want to visit the first two posts linked above. Below the prompt code, I’ve included an image, so you can see it for yourself. If you try the prompt, be sure to change your location within the file system into a nested directory or two, so you can see the prompt update accordingly. It’s a thing of beauty; it really is.

Function Prompt {
	(Get-PSProvider -PSProvider FileSystem).Home = $env:USERPROFILE

	# Determine if Admin and set Symbol variable.
	If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
		$Symbol = '#'
	} Else {
		$Symbol = '$'
	}
	 
	# Write Path to Location Variable as /.../...
	If ($PWD.Path -eq $env:USERPROFILE) {
		$Location = '~'
	} ElseIf ($PWD.Path -like "*$env:USERPROFILE*") {
		$Location = $PWD.Path -replace ($env:USERPROFILE -replace '\\','\\'),'~' -replace '\\','/'
	} Else {
		$Location = "$(($PWD.Path -replace '\\','/' -split ':')[-1])"
	}

	# Determine Host for WindowTitle.
	Switch ($Host.Name) {
		'ConsoleHost' {$HostName = 'ConsoleHost'; break}
		'Windows PowerShell ISE Host' {$HostName = 'ISE'; break}
		default {}
	}

	# Create and write Prompt; Write WindowTitle.
	$Prompt = "[$($env:USERNAME.ToLower())@$($env:COMPUTERNAME.ToLower()) $Location $Symbol]"
	$Host.UI.RawUI.WindowTitle = "$HostName $Prompt $((Get-Location).Drive):\"
	"$Prompt "
}

an-addition-to-the-linux-powershell-prompt-II-01

Linux Prompt on Windows – Part II

A while ago, I wrote myself a new prompt function and shared it here. Well, I’m here to report that I’m still using it in both the ConsoleHost and the ISE. Here’s an image from the first post that shows what it looks like.

duplicate-the-linux-prompt01

The thing about this prompt function, is that it also modified the WindowTitle to reflect the exact same information — the user, the computer, the location on the current drive, and whether or not you’re admin (# = admin vs. ~ = not admin). I love that too, but there’s turned out to be one little inconvenience. Besides the minutely different icons, I can’t quickly tell if I’m about to open the ISE or ConsoleHost from its taskbar icon. Therefore, I modified the prompt function every so slightly to indicate which host is which. Take a look.

an-addition-to-my-linux-powershell-prompt01

Now I can better determine which host I want — CH for ConsoleHost and ISE for, well, the ISE — before I bring it back to the front. As expected, it only took a minor change. I added a switch statement that evaluated the value in $Host.Name. Based on its value, it populated a variable called $HostName that’s used as a part of the assigned valued in the WindowTitle.

Function Prompt {
	(Get-PSProvider -PSProvider FileSystem).Home = $env:USERPROFILE

	# Determine if Admin and set Symbol variable.
	If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
		$Symbol = '#'
	} Else {
		$Symbol = '$'
	}
	 
	# Write Path to Location Variable as /.../...
	If ($PWD.Path -eq $env:USERPROFILE) {
		$Location = '~'
	} ElseIf ($PWD.Path -like "*$env:USERPROFILE*") {
		$Location = $PWD.Path -replace ($env:USERPROFILE -replace '\\','\\'),'~' -replace '\\','/'
	} Else {
		$Location = "$(($PWD.Path -replace '\\','/' -split ':')[-1])"
	}

	# Determine Host for WindowTitle.
	Switch ($Host.Name) {
		'ConsoleHost' {$HostName = 'CH '; break}
		'Windows PowerShell ISE Host' {$HostName = 'ISE'; break}
		default {}
	}

	# Create and write Prompt; Write WindowTitle.
	$Prompt = "$($env:USERNAME.ToLower())@$($env:COMPUTERNAME.ToLower()) $Location $Symbol "
	$Host.UI.RawUI.WindowTitle = "$HostName`: $Prompt"
	$Prompt
}

Update: After a week or so, I updated the function again. I couldn’t stand the capital CH and ISE. So, that’s fixed: It’s ch and ise, now. There may come another change, too. When I’m not on the C:\ drive, I’d like to include an indication in the WindowTitle. Here’s the update.

Linux Prompt on Windows – Part I

I already have an answer to the question, “Why?” Because, I can. At some point in the last few days, I decided I would attempt to replicate the Linux prompt in PowerShell. So I did it, and I thought I would share it. I’ve broken this up a little with the full function toward the bottom of this evening’s post.

In this first section, we’ve created the prompt function’s basic structure and added our first bit of code. This code determines if the user that started the Windows PowerShell session is an administrator or not. If they are, they get the # symbol as part of the prompt, and if they’re not, they get the $ symbol.

Function Prompt {
    If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
        $Symbol = '#'
    } Else {
        $Symbol = '$'
    }
}

The next addition includes the logic to determine how to write the path inside the prompt. If the current path is C:\Users\<CurrentUser>, it enters a tilde (~). If the path includes the C:\Users\<CurrentUser> path, in addition to one or more directories, it will enter a tilde and the other directory or directories, such as ~/Desktop, or ~/Favorites/Links. In the last case, it’ll simply list the current path after replacing the backslashes with forward slashes and dumping the drive letter and colon. In all instances, in fact, all (Windows) backslashes, will be replaced with (Unix/Linux) forward slashes.

Function Prompt {
    If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
        $Symbol = '#'
    } Else {
        $Symbol = '$'
    }

    If ($PWD.Path -eq $env:USERPROFILE) {
        $Location = '~'
    } ElseIf ($PWD.Path -like "*$env:USERPROFILE*") {
        $Location = $PWD.Path -replace ($env:USERPROFILE -replace '\\','\\'),'~' -replace '\\','/'
    } Else {
        $Location = "$(($PWD.Path -replace '\\','/' -split ':')[-1])"
    }
}

The last section is where the prompt function actually writes the prompt to the screen. It’s the simple combination of the current user, an @ character, the computer name, the path, and the proper symbol (# or $). As you may notice, I’ve written the code to force the case of the current user and computer to lowercase.

Function Prompt {
    If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
        $Symbol = '#'
    } Else {
        $Symbol = '$'
    }

    If ($PWD.Path -eq $env:USERPROFILE) {
        $Location = '~'
    } ElseIf ($PWD.Path -like "*$env:USERPROFILE*") {
        $Location = $PWD.Path -replace ($env:USERPROFILE -replace '\\','\\'),'~' -replace '\\','/'
    } Else {
        $Location = "$(($PWD.Path -replace '\\','/' -split ':')[-1])"
    }

    "$($env:USERNAME.ToLower())@$($env:COMPUTERNAME.ToLower()) $Location $Symbol "
}

In closing, I’ve included a gif of the prompt and an example of moving though the directory structure. While I typically only use full cmdlet names in my posts, this example does include aliases for the Set-Location cmdlet (cd, sl, and even chdir). Due to this function being saved in my profile script, this prompt displays immediately when a new console is opened, and every time after that. As someone that’s written a few different prompt functions, this one’s a keeper. I already can’t imaging switching back. On that note, you might not want to test it out.

duplicate-the-linux-prompt01

tommymaynard@srv01 / # $PWD.Path
C:\
tommymaynard@srv01 / # cd C:\Windows\
tommymaynard@srv01 /Windows # cd .\System32\
tommymaynard@srv01 /Windows/System32 # chdir ..
tommymaynard@srv01 /Windows # chdir ..
tommymaynard@srv01 / # sl /users
tommymaynard@srv01 /users # sl /users/tommymaynard2 # Not my current user.
tommymaynard@srv01 /users/tommymaynard2 # cd ..
tommymaynard@srv01 /users # cd C:\Users\tommymaynard\ # My current user.
tommymaynard@srv01 ~ # cd .\Desktop\
tommymaynard@srv01 ~/Desktop # cd ..
tommymaynard@srv01 ~ # cd .\Favorites\Links\
tommymaynard@srv01 ~/Favorites/Links # sl /
tommymaynard@srv01 / # cd /users
tommymaynard@srv01 /users # chdir \
tommymaynard@srv01 / #

Update1: A day later and I still love my new PowerShell prompt. I’ve made a minor change, however. The last line in the function is now the following three lines. It stores the prompt in a variable called $Prompt, modifies the title of the window to the $Prompt value, and then writes the prompt. In the past my window’s title indicate the computer name. Now it indicates that information, as well as the current user, the location on the current drive, and whether or not I’m running the session as an administrator.

...
	$Prompt = "$($env:USERNAME.ToLower())@$($env:COMPUTERNAME.ToLower()) $Location $Symbol "
	$Host.UI.RawUI.WindowTitle = $Prompt
	$Prompt
}

Update2: It occurred to me today that by entering the tilde character, such as Set-Location -Path ~, it moves you to the location stored in the Home property of the FileSystem PSProvider. Because of this, I opted to add another line, just before the beginning of the prompt function. Setting this property to $env:USERPROFILE, allows me to quickly move to C:\Users\<CurrentUser>. I should note that this property is sometimes already set. In those cases, this is just a precaution that the ~ character will move you back home.

(Get-PSProvider -PSProvider FileSystem).Home = $env:USERPROFILE
Function Prompt {
...
}

In case you want to take this prompt function for a spin, and you do, here’s everything. Copy and paste it to your console and hit Enter a couple times and try it out. If you hate it, close and reopen the PowerShell console and it never existed. Cheers.

(Get-PSProvider -PSProvider FileSystem).Home = $env:USERPROFILE
Function Prompt {
    If ([bool](([System.Security.Principal.WindowsIdentity]::GetCurrent()).Groups -match 'S-1-5-32-544')) {
        $Symbol = '#'
    } Else {
        $Symbol = '$'
    }
 
    If ($PWD.Path -eq $env:USERPROFILE) {
        $Location = '~'
    } ElseIf ($PWD.Path -like "*$env:USERPROFILE*") {
        $Location = $PWD.Path -replace ($env:USERPROFILE -replace '\\','\\'),'~' -replace '\\','/'
    } Else {
        $Location = "$(($PWD.Path -replace '\\','/' -split ':')[-1])"
    }

	$Prompt = "$($env:USERNAME.ToLower())@$($env:COMPUTERNAME.ToLower()) $Location $Symbol "
	$Host.UI.RawUI.WindowTitle = $Prompt
	$Prompt
}

 

Run Background Commands after Every Command (Part II)

The first part of this post began on PowerShell.org. Start there, and it’ll get you to Part I: http://powershell.org/wp/2015/10/12/run-background-commands-after-every-command.

Recently I shared a small function I wrote to replace my prompt function. In addition to creating the prompt (PS: C\>) each time one command ended, it would run some background commands. In my attempt to take advantage of this function, I added code that would modify the WindowTitle, the text at the top of the console host or ISE, to indicate if there were any background jobs. Today, I’ve improved the function.

The additions I made include all of the following:
– Uses the singular word “job” when there is only one background job.
– Uses the plural word “jobs” when there is more than one background job.
– Adds an asterisk (*) when any job is actively running.
– Adds a plus sign (+) when any job has more data.

Here’s the full, updated function, and some sequential images beneath that. I’ve dumped the nested If statement for a switch statement, improving the function’s readability. Before you get into this, there’s something to consider. The indicators are only as accurate as the last time the prompt function was invoked. They won’t update without the user pressing the Enter key. That said, it’s quite convenient that you can determine if a background job is still running by pressing Enter. You don’t even have to type anything.

Function Prompt {
    If (-Not($OriginalTitle)) {
        $Global:OriginalTitle = $Host.UI.RawUI.WindowTitle
    }

    If (Get-Job) {
        $Job = Get-Job
        Switch ($Job) {
            {$Job.State -eq 'Running'} {$State = '*'}
            {$Job.HasMoreData -eq $true} {$MoreData = '+'}
            {$Job.Count -eq 1} {$Host.UI.RawUI.WindowTitle = "[$($State)Job$($MoreData)] $OriginalTitle"; break}
            {$Job.Count -gt 1} {$Host.UI.RawUI.WindowTitle = "[$($State)Jobs$($MoreData)] $OriginalTitle"}
        }
    } Else {
        $Host.UI.RawUI.WindowTitle = $OriginalTitle
    }

    "PS $($executionContext.SessionState.Path.CurrentLocation)$('>' * ($nestedPromptLevel + 1)) "
}

Run-background-commands-after-every-command-PartII-01

Run-background-commands-after-every-command-PartII-02

Run-background-commands-after-every-command-PartII-03

Run-background-commands-after-every-command-PartII-04

Update: After looking at this a few more times, I decided to move the asterisk indicator (running jobs) to the back of the word Job, or Jobs, next the plus sign indicator (has more data). I thought it looked better. The code changes I made, are seen below, and a comparison image is down there, too. Cheers!

Function Prompt {
...
            {$Job.Count -eq 1} {$Host.UI.RawUI.WindowTitle = "[Job$($State)$($MoreData)] $OriginalTitle"; break}
            {$Job.Count -gt 1} {$Host.UI.RawUI.WindowTitle = "[Jobs$($State)$($MoreData)] $OriginalTitle"}
...
}

Run-background-commands-after-every-command-PartII-05

Run Background Commands after Every Command

For a complete introduction to this post, please read the first two paragraphs at PowerShell.org: http://powershell.org/wp/2015/10/12/run-background-commands-after-every-command.

There’s a part II, now. Be sure to read that when you’re done here: http://tommymaynard.com/quick-learn-run-background-commands-after-every-command-part-ii-2015.

You know the prompt, it often looks like this: PS C:\> or this: PS>, or even this [DC05]: PS C:\Users\tommymaynard\Documents>, when you’re interactively remoting to another computer. That built-in function determines the appearance of your prompt. I’ve seen several different modifications of the prompt. You can add the the date and time to the prompt, or like the example in the about_Prompt help file, you can add ‘Hello World’ every time the prompt is displayed. Doable, yes, but helpful, probably not.

This post isn’t about changing the prompt’s appearance, but instead about doing something else inside the prompt function. What the prompt looks like is defined by a function called, prompt — you guessed it. Take a look at your current prompt, as in the example below.

PS> (Get-ChildItem -Path Function:\prompt).ScriptBlock
"PS $($executionContext.SessionState.Path.CurrentLocation)$('>' * ($nestedPromptLevel + 1)) "
# .Link
# http://go.microsoft.com/fwlink/?LinkID=225750
# .ExternalHelp System.Management.Automation.dll-help.xml

This is the standard prompt function beginning in PowerShell 3.0 up though PowerShell 5.0, the current version of PowerShell, as of this writing.

This function is invoked each time a command is run and the prompt is displayed again. What if we added additional code inside this function? It would also be run every time a new prompt was displayed. My initial idea was to add the current directory to the WindowTitle. If you don’t know what the WindowTitle is, it’s the text at the top of the console host that says “Administrator: Windows PowerShell,” or “Windows PowerShell,” when in a non-elevated host.

I tried the current directory and quickly realized it took more time to look up at the WindowTitle, from the current prompt, than to leave the default prompt alone and get this information from there. The next idea was to add the date and time to the WindowTitle. This way I would know the time the last prompt was displayed. This is practically the time the last command ended. It seemed useful… for about a minute. I finally decided on putting an indicator in the WindowTitle so that I would know if there were any background jobs or not. I seem to open and close new consoles all day long, and knowing if I was about to dump a console with an active job, whether it was still running or not, or whether it still had data, seemed useful.

Let’s walk though what I did to get this to happen. Before we do that, let’s compare the two images below. The first one shows the standard WindowTitle when there’s no job, and the [Job] indicator when there is a job. We’re going to add a few lines of PowerShell to make this happen.

run-background-commands-after-every-command01run-background-commands-after-every-command02

The first thing I did was to define a function in my profile script ($PROFILE). This function would overwrite the default prompt function, as PowerShell reads in the profile script, after it has already created the default prompt.

Function prompt {

}

Next, I enter the default, prompt text. Notice I’m not changing how the prompt is displayed.

Function Prompt {
    "PS $($executionContext.SessionState.Path.CurrentLocation)$('>' * ($nestedPromptLevel + 1)) "
}

Following this, I added the first piece of conditional logic. We test for a variable called $OriginalTitle. This variable will not exist the first time the prompt function is run, as the variable is created inside this If statement. It effectively ends up holding whatever was in WindowTitle when the console host was first opened. You’ll soon see how we reuse this value.

Before we go on, I should mention that I’ve made this a globally-scoped variable. This is because the variable needs to retain its value outside the function, and it needs to exist each time the function ends. Because of the way scope works, when we enter the function the second time and it can’t find $OriginalText, the function will go up a level and check for the existence of the variable in the parent scope, which in this case is the global scope.

Function Prompt {
    If (-Not($OriginalTitle)) {
        $Global:OriginalTitle = $Host.UI.RawUI.WindowTitle
    }

    "PS $($executionContext.SessionState.Path.CurrentLocation)$('>' * ($nestedPromptLevel + 1)) "
}

In the next part of the function, I added a check to see if the Get-Job cmdlet returns anything. If it does, there are current background jobs, and if it doesn’t, then there are no current background jobs. We’ll start with what happens when there aren’t any jobs, first. In the Else portion of this If-Else statement, we set the current WindowTitle to whatever is stored in the $OriginalTitle variable. This ensures that the WindowTitle looks just like it did when we initially started the console host and there were no background jobs.

Function Prompt {
    If (-Not($OriginalTitle)) {
        $Global:OriginalTitle = $Host.UI.RawUI.WindowTitle
    }

    If (Get-Job) {
        # Coming
    } Else {
        $Host.UI.RawUI.WindowTitle = $OriginalTitle
    }

    "PS $($executionContext.SessionState.Path.CurrentLocation)$('>' * ($nestedPromptLevel + 1)) "
}

So what happens when there are jobs? In this final portion of the function, we have an embedded If statement. If the current WindowTitle doesn’t already include the string [Job], then we add it. If it’s already there, then we leave it alone, and write the prompt.

Function Prompt {
    If (-Not($OriginalTitle)) {
        $Global:OriginalTitle = $Host.UI.RawUI.WindowTitle
    }

    If (Get-Job) {
        If ($Host.UI.RawUI.WindowTitle -NotLike '[Job]*') {
            $Host.UI.RawUI.WindowTitle = "[Job] $OriginalTitle"
        }
    } Else {
        $Host.UI.RawUI.WindowTitle = $OriginalTitle
    }

    "PS $($executionContext.SessionState.Path.CurrentLocation)$('>' * ($nestedPromptLevel + 1)) "
}

Thanks to the prompt function, we have another way to do something the moment the console is opened, and now, every time a new command is entered and a new prompt is displayed in the host. This little project has already got me wondering about some other things I may want to try with this function. I might expand what I’ve done so far, and provide indicators when there’s more than one job ([Job] vs. [Jobs]), if the jobs are still running, and perhaps if they have more data (whether it hasn’t been received yet, or was kept when it was received).

Keep in mind that this function runs after every command, successful or otherwise. Do your best not to overload the actions in the function. The default prompt comes in under a millisecond. My prompt, with the code above added, comes in at an average of 1 millisecond. If you end up doing too much in the function, you might end up waiting longer than you’re used to, making your additions to the function questionable.

Have fun, and thanks to everyone for reading this post.