100

I would like to translate this Linux/Bash script to Windows shell:

if test -d myDirName; then echo "ok"; else mkdir myDirName; fi

It tests if a directory exists, and if it doesn't it creates it.

studiohack
  • 13,477
Pietro
  • 1,861

10 Answers10

121
@echo off
IF exist myDirName ( echo myDirName exists ) ELSE ( mkdir myDirName && echo myDirName created)

Added by Barlop

While the above works for this particular situation, the title says about testing specifically for a directory. Phogg's comment using if exist mydirname\ rather than if exist mydirname is the way. Some answers have used \nul but \nul is problematic in NT. Not including a trailing backslash will test for a file or a directory. So, for a directory, include the trailing backslash.

barlop
  • 25,198
23

Here is what I just found out:

You can test if a nul file exists; if the directory exists it will contain a nul file, if the nul file does not exist then the directory does not exist.

IF exist myDirName/nul ( echo myDirName exists ) ELSE ( mkdir myDirName && echo myDirName created)
dev008
  • 231
14

Use a backslash, not forward slash: myDirName\nul not myDirName/nul

md foo 
echo.>bar 
for %I in (foo bar xyz) do @( 
  if exist %I ( 
    if exist %I\nul ( 
      echo -- %I is a directory 
    ) else ( 
      echo -- %I is a file 
    ) 
  ) else ( 
    echo -- %I does not exist 
  ) 
)

-- foo is a directory
-- bar is a file
-- xyz does not exist

edit: this only works if directory name does not contain spaces

DVF
  • 141
  • 1
  • 3
7

Some have suggested doing \nul, but that doesn't seem to work reliably in NT

C:\blah>md abc

C:\blah>if exist abc\nul echo yes
yes

C:\blah>if exist "abc\nul" echo yes

C:\blah>

http://www.dostips.com/forum/viewtopic.php?f=3&t=4913

foxidrive writes-

The trick with nul worked in pre NT versions of windows.

Now you would use this, with a trailing backslash.

if exist "C:\abcde\" echo the folder exists

Re the question

C:\blah>if exist "abcd\" (echo yes) else (echo no && mkdir abcd)
no

C:\blah>if exist "abcd\" (echo yes) else (echo no && mkdir abcd)
yes

C:\blah>
barlop
  • 25,198
4

I wondered why joe had a downvote as I was experiencing the same kind of problem on Windows 7, namely that

IF EXIST filename\NUL

was returning TRUE for both files and directories. I found an alternative solution at www.robvanderwoude.com/battech_ifexistfolder.php and came up with a revised version of DVF's FOR loop:

FOR %I in (foo bar xyz) DO @( PUSHD %I && (POPD & echo -- %I is a directory) || ( IF exist %I ( echo -- %I is a file ) ELSE ( echo -- %I does not exist ) ) )
Damian
  • 41
3

I see many have problems with differentiating between files and folders. Has anyone tried to simply cd into it after checking it exists? Then cd will either succeed or fail.

set MyDir = "MyTestDir"
IF exist MyDir (
    cd MyDir 
    IF ERRORLEVEL NEQ 0 (
        echo "Error: %MyDir% already exists, but it is a file!"
        exit 1
    ) else (
        # Do not forget to cd back
        cd ..
    )
) else (
   # Did not exist yet, so create it.
   mkdir MyDir
)
1

Here's a way to test the directory exists only when its a valid directory.

set myDirName=foobitybarbitybaz
dir /A:D %myDirName% >nul 2>&1
if ERRORLEVEL 1 (@mkdir %myDirName%) else (@echo "ok")

0

I prefer using dir /d | findstr \[\.\.\]:

2>nul dir /d "myDirName" | findstr \[\.\.\] >nul && echo= "ok" || mkDir myDirName&&echo= Is NOT dir


2>nul dir /d "myDirName" | findstr \[\.\.\] >nul && echo= "ok" || mkDir myDirName


For create if exist or not and for ignore error...

2>nul mkDir myDirName

Also ...

if exist "myDirName\." (echo/"ok") else mkdir myDirName

rem :: or direct create myDirName hidden/ignoring error
       2>nul mkdir myDirName & if exist "myDirName\." echo/ exist 
rem :: output: exist 
Io-oI
  • 9,237
0
exist myDirName/nul

also is true if myDirName is a file, whis is not the searched functionality

Joe
  • 11
-1

Finding a folder shouldn't be this difficult. My solution, use perl:

for($cnt=$#ARGV; $cnt>=0; --$cnt)
{
   if ( -d "$ARGV[$cnt]" ) { 
      print "argv[$cnt]=$ARGV[$cnt] is a folder\n";
      $dir = $ARGV[$cnt];
      break;
   } else {
      print "argv[$cnt]=$ARGV[$cnt] is Not a folder\n";
   }
}