Empty variable substitution

[andry81]

Example:

@echo off

setlocal DISABLEEXTENSIONS

echo %C:\xxx
for %%i in (C:\yyy) do call echo %%%%i
echo %C:~0,1

setlocal ENABLEEXTENSIONS

echo %C:\xxx
for %%i in (C:\yyy) do call echo %%%%i
echo %C:~0,1

Output:

C:\xxx
C:\yyy
C:~0,1
\xxx
\yyy
~0,1

[jeb-de]

Interesting, didn't know this.

If you want to test, that multiple variables are all empty you can do:

if "%var1:E%var2:E%var3:E%" == "EEE" ECHO all variables are empty

The good thing is, it works even when there is content like:

set "var2=&"^&"
if "%var1:E%var2:E%var3:E%" == "EEE" ECHO all variables are empty