Practice environment variables: %VAR%, set, PATH and setx

Practice environment variables in a safe Windows Command Prompt: read %USERPROFILE%, make your own with set, inspect PATH, and save a value for new windows with setx.

COMMAND LINE CODEX// a wizard's guide to the Windows command line

0/54 quests complete

C:\Codex\cmd.exesandbox · nothing here touches your real PC

Command Line Codex practice shell [Version 1.0]

A safe sandbox: every file here is pretend, so experiment freely.

Type HELP for the list of commands, or pick a chapter to begin.

C:\Users\Apprentice>

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┤ CHAPTER XIII ├

Runes of the Realm

Environment variables are named values the shell carries with it. Wrap a name in percent signs and the shell swaps in its value: echo %USERPROFILE% prints your home folder. set name=value makes your own, for this window only.

PATH is the list of folders searched for programs. Empty it and even ping stops working (try it here, safely). setx saves a value for good, but only new windows see it: open one with start cmd.

COMMANDS — click one to load it into the prompt

read a built-in variable
make one of your own
read it back
where programs are found
save one for new windows

QUESTS

[ ]Read a variable with echo %NAME%
[ ]Create your own with set
[ ]Save one for good with setx

Next chapter →

From the Codex

The commands in this chapter

echoPrint text to the screen, or toggle command echoing.set / setlocal / endlocalDisplay, create, or change environment variables; localize changes to a batch file's scope.setxPermanently set an environment variable — unlike set, it persists after the window closes.