Test if Directory exists in Batch file (.cmd)

My previous post on testing network drives led me to further research the topic, and I came to quite surprising (at least for me) results: the result if a check with IF EXIST depend on whether

• the drive is a local drive or a mapped network drive or a UNC path

• the path contains spaces or not

• the path is quoted or not

• cmd runs in administrator mode or user mode

I wrote a small batch file that contains a couple of assignments of the form

set dir=c:\temp
set dir=c:\temp\with spaces
etc.

and executed these tests on each value

if exist %dir% echo exists
if exist %dir%\nul echo exists
if exist %dir%\. echo exists
if exist "%dir%" echo exists
if exist "%dir%\nul" echo exists
if exist "%dir%\." echo exists

These are the results

directory	%dir%	%dir%\nul	%dir\.	“%dir%”	“%dir%\nul”	“%dir%\.”
local	x	x	x	x		x
local (spaces)	-	-	-	x		x
mapped (non-admin)	x	x	x	x		x
mapped (non-admin, spaces)	-	-	-	x		x
UNC	x	x	x	x	x	x
UNC (spaces)	-	-	-	x	x	x

Comments:

Testing directory path containing spaces can only be performed using the quoted notation.

Mapped network drives can only be access in non-administrator mode (see these threads).

The only reliable way to test for directory existence is therefore to use the quoted “%dir%\.” notation.

To check whether cmd runs in administrator mode or not, use an admin statement such as ‘at’:

at >nul 2>nul
if errorlevel 1 echo you are not in administrator mode

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