windowsfilecmdcommand-line

How can I create an empty file at the command line in Windows?

How can I create an empty file at the DOS/Windows command-line?

I tried:

copy nul > file.txt

But it always displays that a file was copied.

Is there another method in the standard cmd?

It should be a method that does not require the touch command from Cygwin or any other nonstandard commands. The command needs to run from a script, so keystrokes cannot be used.

Solution

  • Without redirection, Luc Vu or Erik Konstantopoulos point out to:

    copy NUL EMptyFile.txt
copy /b NUL EmptyFile.txt

    "How to create empty text file from a batch file?" (2008) also points to:

    type NUL > EmptyFile.txt
# also
echo. 2>EmptyFile.txt
copy nul file.txt > nul # also in qid's answer below
REM. > empty.file
fsutil file createnew file.cmd 0 # to create a file on a mapped drive

    Nomad mentions an original one:

    C:\Users\VonC\prog\tests>aaaa > empty_file
'aaaa' is not recognized as an internal or external command, operable program or batch file.

C:\Users\VonC\prog\tests>dir

 Folder C:\Users\VonC\prog\tests

27/11/2013  10:40    <REP>          .
27/11/2013  10:40    <REP>          ..
27/11/2013  10:40                 0 empty_file

    In the same spirit, Samuel suggests in the comments:

    the shortest one I use is basically the one by Nomad:

    .>out.txt

    It does give an error:

    '.' is not recognized as an internal or external command

    But this error is on stderr. And > only redirects stdout, where nothing have been produced.
    Hence the creation of an empty file.
    The error message can be disregarded here. Or, as in Rain's answer, redirected to NUL:

    .>out.txt 2>NUL

    (Original answer, November 2009)

    echo.>filename

    (echo "" would actually put "" in the file! And echo without the '.' would put "Command ECHO activated" in the file...)

    Note: the resulting file is not empty but includes a return line sequence: 2 bytes.

    This discussion points to a true batch solution for a real empty file:

     <nul (set/p z=) >filename

 dir filename
 11/09/2009  19:45                 0 filename
 1 file(s)                         0 bytes

    The "<nul" pipes a nul response to the set/p command, which will cause the variable used to remain unchanged. As usual with set/p, the string to the right of the equal sign is displayed as a prompt with no CRLF.

    Since here the "string to the right of the equal sign" is empty... the result is an empty file.

    The difference with cd. > filename (which is mentioned in Patrick Cuff's answer and does also produce a 0-byte-length file) is that this "bit of redirection" (the <nul... trick) can be used to echo lines without any CR:

    <nul (set/p z=hello) >out.txt
<nul (set/p z= world!) >>out.txt
dir out.txt

    The dir command should indicate the file size as 11 bytes: "helloworld!".