Customize Windows Cmder Prompt

git.lua

---
 -- Find out current branch
 -- @return {false|git branch name}
---
function get_git_branch()
    for line in io.popen("git branch 2>nul"):lines() do
        local m = line:match("%* (.+)$")
        if m then
            return m
        end
    end

    return false
end

---
 -- Get the status of working dir
 -- @return {bool}
---
function get_git_status()
    return os.execute("git diff --quiet --ignore-submodules HEAD")
end

function git_prompt_filter()

    -- Colors for git status
	-- clean = "\x1b[1;37;40m",
	-- dirty = "\x1b[31;1m",
    local colors = {
		clean = "\x1b[34;42m\x1b[37;42m",
        dirty = "\x1b[34;43m\x1b[30;43m",
    }

    local branch = get_git_branch()
    if branch then
        -- Has branch => therefore it is a git folder, now figure out status
        if get_git_status() then
			-- clean
            color = colors.clean
			clink.prompt.value = string.gsub(clink.prompt.value, "{git}", color.."  "..branch.." \x1b[32;40m")
        else
			-- dirty
            color = colors.dirty
			clink.prompt.value = string.gsub(clink.prompt.value, "{git}", color.."  "..branch.." \x1b[33;40m")
        end
        
        return true
    end

    -- No git present or not in git file
    clink.prompt.value = string.gsub(clink.prompt.value, "{git}", " \x1b[34;40m")
    return false
end

clink.prompt.register_filter(git_prompt_filter, 50)

init.bat

:: Init Script for cmd.exe
:: Sets some nice defaults
:: Created as part of cmder project

:: Find root dir
@if not defined CMDER_ROOT (
    for /f %%i in ("%ConEmuDir%\..\..") do @set CMDER_ROOT=%%~fi
)

:: Change the prompt style
:: Mmm tasty lamb
@prompt $E[37;44m$P$S{git}$_$E[34;40m{lamb}$S$E[0m
::@prompt $E[1;32;40m$P$S{git}$S$_$E[1;30;40m{lamb}$S$E[0m
::@prompt $E[1;32;40m$P$S$S$_$E[1;30;40m$G$S$E[0m

:: Pick right version of clink
@if "%PROCESSOR_ARCHITECTURE%"=="x86" (
    set architecture=86
) else (
    set architecture=64
)

:: Run clink
@"%CMDER_ROOT%\vendor\clink\clink_x%architecture%.exe" inject --quiet --profile "%CMDER_ROOT%\config"

:: Prepare for msysgit

:: I do not even know, copypasted from their .bat
@set PLINK_PROTOCOL=ssh
@if not defined TERM set TERM=cygwin

:: Enhance Path
@set git_install_root=%CMDER_ROOT%\vendor\msysgit
@set PATH=%CMDER_ROOT%\bin;%git_install_root%\bin;%git_install_root%\mingw\bin;%git_install_root%\cmd;%git_install_root%\share\vim\vim74;%CMDER_ROOT%;%PATH%

:: Add aliases
@doskey /macrofile="%CMDER_ROOT%\config\aliases"

:: Set home path
@if not defined HOME set HOME=%USERPROFILE%

@if defined CMDER_START (
    @cd /d "%CMDER_START%"
) else (
    @if "%CD%\" == "%CMDER_ROOT%" (
        @cd /d "%HOME%"
    )
)

prompt.lua

function lambda_prompt_filter()
    clink.prompt.value = string.gsub(clink.prompt.value, "{lamb}", "λ")
end

clink.prompt.register_filter(lambda_prompt_filter, 40)

where do you place the prompt.lua file?

Not sure if it's still relevant to you @iborg019, but the prompt.lua just goes in the cmder/config folder with the git.lua.