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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.

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3  
The actual linux/bash command would simply be: mkdir -p myDirName. After spending days trying to translate relatively simple bash-scripts into batch-sh*t (assigning the result of a function to a variable?), I've decided to just make people install cygwin. –  michael_n Mar 30 '13 at 11:00

7 Answers 7

up vote 46 down vote accepted
@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.

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17  
This is correct for testing file existence, but how do you know that it's a directory? The simplest answer is if exist mydirname\ and the rest as you say. Alternately, you could actually get a test binary and use it on Windows. –  phogg Dec 6 '10 at 16:58
    
@phogg: In the context of this specific question: if it exists but is a file, you still cannot mkdir it. –  grawity Dec 6 '11 at 13:09
    
@grawity: If it exists but is a file the script will probably fail later when trying to use it as a directory, which probably isn't what you want. –  phogg Dec 6 '11 at 13:30
    
how can i check if not exist? –  Sungguk Lim Jan 9 at 6:43
1  
@sunglim by writing ` If not exist myDirName\ ` similarly if not 1==1 echo hmm or if exist myDirName\ ELSE blahblahblah –  barlop Jun 3 at 11:13

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>
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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
)
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The point is, have you tried? Otherwise this is not an answer. –  Chenmunka Jun 3 at 10:11
    
This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post - you can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post. –  Moses Jun 3 at 14:47
    
(1) If you’re going to use a variable, use the variable. All occurrences of MyDir after the first line should be %MyDir%. (2) The cd .. won’t do what you want if %MyDir% is a multi-level pathname (e.g., Pictures\cats) or even an absolute pathname (e.g., \Windows). Consider using pushd/popd and/or setlocal. –  Scott Jun 3 at 17:02

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

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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 ) ) )
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exist myDirName/nul

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

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C:\blah>touch abe<ENTER>C:\blah>if exist abe\nul echo err<ENTER> C:\blah>if exist abe/nul echo err<ENTER>C:\blah> i'm no fan of \nul in NT but it isn't. You should have given some output. –  barlop Jun 3 at 11:17

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)
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2  
+1 - this works in all Windows and MS-DOS versions, unlike plain if exist dirname which appears to be specific to Windows NT. –  grawity Dec 6 '11 at 13:09
    
that's wAS a stupid code compare to linux mkdir -p myDirName :p –  Kit Ho Jan 4 '13 at 9:35
6  
It should be a backslash, not a forward slash. –  Nathan Garabedian Feb 1 '13 at 23:08
    
@grawity What do you think of this though, apparently some issue with doing \nul? dostips.com/forum/viewtopic.php?f=3&t=4913 –  barlop Jun 3 at 11:03
    
@barlop: I think that cmd.exe is one of the worst scripting languages in existence, and that one should use PowerShell or other alternatives if at all possible. As for \nul, it is not necessary in Windows NT anymore, plain if exist "C:\Program Files (x86)" should work (unless you're still targetting Windows 98...) –  grawity Jun 3 at 11:17

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