Can a Windows batch file determine its own file name?

You can get the file name, but you can also get the full path, depending what you place between the '%~' and the '0'. Take your pick from

d -- drive p -- path n -- file name x -- extension f -- full path 

E.g., from inside c:\tmp\foo.bat, %~nx0 gives you "foo.bat", whilst %~dpnx0 gives "c:\tmp\foo.bat". Note the pieces are always assembled in canonical order, so if you get cute and try %~xnpd0, you still get "c:\tmp\foo.bat"

Using the following script, based on SLaks answer, I determined that the correct answer is:

echo The name of this file is: %~n0%~x0 echo The name of this file is: %~nx0 

And here is my test script:

@echo off echo %0 echo %~0 echo %n0 echo %x0 echo %~n0 echo %dp0 echo %~dp0 pause 

What I find interesting is that %nx0 won't work, given that we know the '~' char usually is used to strip/trim quotes off of a variable.

Bear in mind that 0 is a special case of parameter numbers inside a batch file, where 0 means this file as given on the command line.

So if the file is myfile.bat, you could call it in several ways as follows, each of which would give you a different output from the %0 or %~0 usage:

myfile

myfile.bat

mydir\myfile.bat

c:\mydir\myfile.bat

"c:\mydir\myfile.bat"

All of the above are legal calls if you call it from the correct relative place to the directory in which it exists. %~0 strips the quotes from the last example, whereas %0 does not.

Because these all give different results, %0 and %~0 are very unlikely to be what you actually want to use.

Here's a batch file to illustrate:

@echo Full path and filename: %~f0 @echo Drive: %~d0 @echo Path: %~p0 @echo Drive and path: %~dp0 @echo Filename without extension: %~n0 @echo Filename with extension: %~nx0 @echo Extension: %~x0 @echo Filename as given on command line: %0 @echo Filename as given on command line minus quotes: %~0 @REM Build from parts @SETLOCAL @SET drv=%~d0 @SET pth=%~p0 @SET fpath=%~dp0 @SET fname=%~n0 @SET ext=%~x0 @echo Simply Constructed name: %fpath%%fname%%ext% @echo Fully Constructed name: %drv%%pth%%fname%%ext% @ENDLOCAL pause 

Try to run below example in order to feel how the magical variables work.

@echo off SETLOCAL EnableDelayedExpansion echo Full path and filename: %~f0 echo Drive: %~d0 echo Path: %~p0 echo Drive and path: %~dp0 echo Filename without extension: %~n0 echo Filename with extension: %~nx0 echo Extension: %~x0 echo date time : %~t0 echo file size: %~z0 ENDLOCAL 

The related rules are following.

%~I - expands %I removing any surrounding quotes ("") %~fI - expands %I to a fully qualified path name %~dI - expands %I to a drive letter only %~pI - expands %I to a path only %~nI - expands %I to a file name only %~xI - expands %I to a file extension only %~sI - expanded path contains short names only %~aI - expands %I to file attributes of file %~tI - expands %I to date/time of file %~zI - expands %I to size of file %~$PATH:I - searches the directories listed in the PATH environment variable and expands %I to the fully qualified name of the first one found. If the environment variable name is not defined or the file is not found by the search, then this modifier expands to the empty string 

Below is my initial code:

@echo off Set z=%% echo. echo %z%0.......%0 echo %z%~0......%~0 echo %z%n0......%n0 echo %z%x0......%x0 echo %z%~n0.....%~n0 echo %z%dp0.....%dp0 echo %z%~dp0....%~dp0 echo. 

I noticed that file name given by %~0 and %0 is the way it was entered in the command-shell and not how that file is actually named. So if you want the literal case used for the file name you should use %~n0. However, this will leave out the file extension. But if you know the file name you could add the following code.

set b=%~0 echo %~n0%b:~8,4% 

I have learned that ":~8,4%" means start at the 9th character of the variable and then show show the next 4 characters. The range is 0 to the end of the variable string. So %Path% would be very long!

fIlEnAmE.bat 012345678901 

However, this is not as sound as Jool's solution (%~x0) above.

My Evidence:

C:\bin>filename.bat %0.......filename.bat %~0......filename.bat . . . C:\bin>fIlEnAmE.bat %0.......fIlEnAmE.bat %~0......fIlEnAmE.bat %n0......n0 %x0......x0 %~n0.....FileName %dp0.....dp0 %~dp0....C:\bin\ %~n0%b:~8,4%...FileName.bat Press any key to continue . . . C:\bin>dir Volume in drive C has no label. Volume Serial Number is CE18-5BD0 Directory of C:\bin . . . 05/02/2018 11:22 PM 208 FileName.bat 

Here is the final code

@echo off Set z=%% set b=%~0 echo. echo %z%0.......%0 echo %z%~0......%~0 echo %z%n0......%n0 echo %z%x0......%x0 echo %z%~n0.....%~n0 echo %z%dp0.....%dp0 echo %z%~dp0....%~dp0 echo. echo A complex solution: echo =================================== echo %z%~n0%z%b:~8,4%z%...%~n0%b:~8,4% echo =================================== echo. echo The preferred solution: echo =================================== echo %z%~n0%z%~x0.......%~n0%~x0 echo =================================== pause