How do you use SETLOCAL in a batch file?

Question

How do you use setlocal in a batch file? I am just learning scripting and would like it explained to me in very simple terms.

I have a script that stops

Answer 1

You make the first line SETLOCAL. This example is from the linked article below:

rem *******Begin Comment**************
rem This program starts the superapp batch program on the network,
rem directs the output to a file, and displays the file
rem in Notepad.
rem *******End Comment**************
@echo off
setlocal
path=g:\programs\superapp;%path%
call superapp>c:\superapp.out
endlocal
start notepad c:\superapp.out

The most frequent use of SETLOCAL is to turn on command extensions and allow delayed expansion of variables:

SETLOCAL ENABLEEXTENSIONS ENABLEDELAYEDEXPANSION

For more info on SETLOCAL see the Command Line Reference at Microsoft TechNet.

Direct link to Setlocal

Answer 2

Try this:

SET PATH=%PATH%;%~dp0;

This will get your local folder your are running the batch from and add it to the current path.

example: if your are running a .bat or .cmd from d:\tools\mybatch.bat it will add d:\tools to the current path so that it may find additional files on that folder.

Answer 3

Suppose this code:

If "%getOption%" equ  "yes" (
   set /P option=Enter option: 
   echo Option read: %option%
)

Previous code will NOT work becase %option% value is replaced just one time when the IF command is parsed (before it is executed). You need to "delay" variable value expansion until SET /P command had modified variable value:

setlocal EnableDelayedExpansion
If "%getOption%" equ  "yes" (
   set /P option=Enter option: 
   echo Option read: !option!
)

Check this:

set var=Before
set var=After & echo Normal: %var%  Delayed: !var!

Guess what the output is...