Runnable Kotlin Script example with windows batch(double click .bat file to run) -- This example Searches all neighbor folders for android projects and deletes project and it's modules "build" folders(For reducing disk size). *need one time set "kotlinc" enviroment variable(See comments for guidance).

DeleteBuildFolders.bat

%kotlinc% -script DeleteBuildFolders.kts -- -dir .
:: "." is default path you can change it to any folder you want to work on that folder ^
:: (script workes on current folder without "-dir" argument)"
:: "^" can be used for multiline commands

DeleteBuildFolders.kts

import java.io.File

// Get the passed in path, i.e. "-d some/path" or use the current path.
val path = if (args.contains("-d")) args[1 + args.indexOf("-dir")]
else "."

println("Processing in folder: $path")
println()
fun deleteBuildFolders(path: String) {

    val folders = File(path)
            .walk()
            .maxDepth(2)
            .onEnter { it.isDirectory }
            .map { File(it.path + "/build") }
            .filter(File::canWrite)
            .toList()

    if (folders.isEmpty()) {

        println("No Android Project folders found")
    }

    folders.forEach { folder ->
        val deleted = folder.deleteRecursively()
        if (deleted) println(folder.path + " Deleted")
    }

}

deleteBuildFolders(path)
println()
println("Press Enter to close")

System.`in`.read()

First way: Open a cmd and type this:
setx kotlinc "%USERPROFILE%\.AndroidStudio4.0\config\plugins\Kotlin\kotlinc\bin\kotlinc" Second way: create a new variable in "Environment Variables" of windows with value of:
%USERPROFILE%\.AndroidStudio4.0\config\plugins\Kotlin\kotlinc\bin\kotlinc

"AndroidStudio4.0" used here, change it to your installed version of AndroidStudio or IntellijIdea(Make sure Kotlin plugin is installed)

For me it deleted 5G.B

--dir command argument used here. You can have any number of arguments with any name you want and receive it in code with args