A Simple Unix Style Prompt in PowerShell

prompt.ps1

# ===Prompt Synopsis===
# - Inspired by https://github.com/rwxrob
# - A simple Unix style prompt in PowerShell
# - Requires git to be installed
# - "user@host:dir(branch)$ "

# ===Color Mapping===
# user   - yellow
# @      - black
# host   - blue
# dir    - magenta
# (      - black
# branch - cyan|red
# )      - black
# $      - yellow

# ===Explanation===
# - The "user" is defined by $env:USERNAME
# - The "host" is defined by $env:COMPUTERNAME
#   - If you don't like how these look you can always define these as
#     hard coded strings below, i.e. $u = "bob" and $h = "windows"
#
# - The "dir" is the basename of the current working directory. If the
#   current directory is the same as $HOME "dir" will be a "~"
#
# - The "branch" is the current git branch checked out. If the current
#   directory is not in a git repository then the entire "(branch)" segment
#   will be omitted. If the current branch is "master" or "main" the color
#   will be red. Otherwise the branch color is cyan.
#
# - The "@", ":", "(", ")" and "$" are those literal symbols
#
# - If you want to change any of the colors just replace the color variables
#   in the "WriteOutput" command to whatever you like.

# ===Color Abbreviation===
# x = reset
# k = blacK   r = Red
# g = Green   y = Yellow
# b = Blue    m = Magenta
# c = Cyan    w = White
function prompt {
    $esc = [char]0x1b
    $x   = "$esc[0m"
    $k   = "$esc[90m"
    $r   = "$esc[91m"
    $g   = "$esc[92m"
    $y   = "$esc[93m"
    $b   = "$esc[94m"
    $m   = "$esc[95m"
    $c   = "$esc[96m"
    $w   = "$esc[97m"
    
    $sep = [regex]::Escape([IO.Path]::DirectorySeparatorChar)
    $dir = $PWD.Path -replace ".*$sep"
    if ( $PWD.Path -eq $HOME ) {
        $dir = "~"
    }

    $br = git branch --show-current 2> $null
    if ( $br ) {
        $brc = $c
        if ( $br -eq "main" -or $br -eq "master" ) {
            $brc = $r
        }
        $br = "$k($brc$br$k)"
    }
    
    $u   = $env:USERNAME
    $h   = $env:COMPUTERNAME
    $end = "$"
    Write-Output "$y$u$k@$b$h${k}:$m$dir$br$y$end$x "
}