A variation on my PowerShell box prompt. This should work cross-platform on PowerShell Core.

BoxPrompt2.ps1

#requires -version 5.1

<#
This is a variation of the BoxPrompt code you can find at https://gist.github.com/jdhitsolutions/df808116f9234c070bdaf233418ec59b

Create a lined box with user and location information. The line color will indicate if the user is running elevated.
The prompt will also display the current date and time and a PS prompt with the PowerShell version.

┌───────────────────────┐
│ [BOVINE320\Jeff] C:\  │
│ 1/21/2019 10:49:22 AM │
└───────────────────────┘
 v5.1.17763 PS>

This prompt should run cross platform, although Linux testing has been limited.

┌─────────────────────┐
│ [jeff] /home/jeff   │
│ 1/21/19 10:49:18 AM │
└─────────────────────┘
 v6.1.2 PS>

To use the prompt dot source the script file in your PowerShell profile script.

This may not display properly in the Visual Studio Code PowerShell integrated console.
#>

Function prompt {

    if ($env:userdomain -AND $env:username) {
        $me = "$($env:userdomain)\$($env:username)"
    }
    elseif ($env:LOGNAME) {
        $me = $env:LOGNAME
    }
    else {
        #last resort
        $me = "PSUser"
    }

    #define lines of text to include in the box
    $text1 = "[$me] $($executionContext.SessionState.Path.CurrentLocation)"
    $text2 = ((Get-Date).ToString()).trim()

    if ($IsLinux) {
        if ($(id -g) -eq 0 ) {
            #running as SU
            $lineColor = "Red"
        }
        else {
            $lineColor = "Green"
        }
    }
    elseif ($isWindows -or $psEdition -eq 'desktop') {
        $IsAdmin = [System.Security.Principal.WindowsPrincipal]::new([System.Security.Principal.WindowsIdentity]::GetCurrent() ).IsInRole("Administrators")
        if ($IsAdmin) {
            $lineColor = "Red"
        }
        else {
            $lineColor = "Green"
        }
    }
    else {
        #for everything else not tested
        $lineColor = "Yellow"
    }

    #get the length of the longest line in the box and uas that to calculate lengths and padding
    $longest = $text1.length, $text2.length | Sort-Object | Select-Object -last 1
    $len = $longest + 2
    $top = "┌$(("─" * $len))┐"
    Write-Host $top -ForegroundColor $lineColor
    Write-Host "│ " -ForegroundColor $lineColor -NoNewline
    Write-Host $text1.PadRight($longest, ' ') -NoNewline
    Write-Host " │" -ForegroundColor $lineColor
    Write-Host "│ " -ForegroundColor $lineColor -NoNewline
    Write-Host $text2.PadRight($longest, ' ') -NoNewline -ForegroundColor yellow
    Write-Host " │" -ForegroundColor $lineColor
    $bottom = "└$(("─" * $len))┘"
    Write-Host $bottom -ForegroundColor $lineColor

    #parse out the PSVersionTable to most meaningful values
    $ver = $(([regex]"\d+\.\d+.\d+").match($psversiontable.psversion).value)

    #the prompt function needs to write something to the pipeline
    " v$($ver) PS$('>' * ($nestedPromptLevel + 1)) "

}