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Posted: **19 Apr 2013 21:38**

It works it seems for dirty cmd line parrameters?

if !"%~1" equ ""! goto :whatever

Posted: **20 Apr 2013 00:01**

This might be useful if you want to check if 1) %1 is empty AND 2) delayed expansion is on.

Posted: **20 Apr 2013 00:13**

I have tested the following codes.

Code: Select all

@echo off
setlocal enableextensions enabledelayedexpansion
echo.
echo  SETLOCAL with ENABLEDELAYEDEXPANSION
if !"%~1" equ ""! goto :whatever
echo.
echo First parameter: %1
goto :eof

:whatever
echo.
echo No parameter.

Code: Select all

@echo off
setlocal enableextensions disabledelayedexpansion
echo.
echo  SETLOCAL with DISABLEDELAYEDEXPANSION
if !"%~1" equ ""! goto :whatever
echo.
echo First parameter: %1
goto :eof

:whatever
echo.
echo No parameter.

Here the result of this codes:

Code: Select all

C:\Test2>test40

 SETLOCAL with ENABLEDELAYEDEXPANSION

No parameter.

C:\Test2>test40 Hallo Peggy Sue

 SETLOCAL with ENABLEDELAYEDEXPANSION

First parameter: Hallo

C:\Test2>test40

 SETLOCAL with DISABLEDELAYEDEXPANSION

First parameter:

C:\Test2>test40 Hallo Peggy Sue

 SETLOCAL with DISABLEDELAYEDEXPANSION

First parameter: Hallo

C:\Test2>

When use SETLOCAL DISABLEDELAYEDEXPANSION is the IF construct: IF !"" equ ""! goto :whatever when the parameter ist empty.

Posted: **20 Apr 2013 01:10**

Code: Select all

@ECHO OFF & setlocal disabledelayedexpansion
if !"%~1" equ ""! (echo equal) else echo not equal
setlocal enabledelayedexpansion
if !"%~1" equ ""! (echo equal) else echo not equal

Output without parameter is:

Code: Select all