How to create an empty file at the command line?

Question

How to 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 any other 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.

Answer 1

echo "" > filename

I believe this works on Windows/DOS, but my last hands-on experience with either is quite a while ago. I do know for a fact that it works on basically any POSIX compliant OS.

Answer 2

I'm using curly { } brackets for enter and Ctrl+Z keyboard

copy con SomeFile.txt {enter}

{Ctrl+Z} {enter}

Answer 3

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 12 bytes: "hello world!".

Answer 4

You can write your own touch.

//touch.cpp
#include <fstream>
#include <iostream>

int main(int argc, char ** argv;)
{
  if(argc !=2)
  {
    std::cerr << "Must supply a filename as argument" << endl;
    return 1;
  }
  std::ofstream foo(argv[1]);
  foo.close();
  return 0;
}

Answer 5

Reading comments on my post, I have to admit I didn't read the question right.

On the Windows command-line, one way would be to use fsutil:

fsutil file createnew <filename> <size>

An example:

fsutil file createnew myEmptyFile.txt 0

---

Below is for *nix command-line.

touch filename

This command changes your modified date of a file or creates it if file is not found.

Answer 6

If you really want a totally empty file, without any output to stdout, you can cheat a little:

copy nul file.txt > nul

Just redirect stdout to nul, and the output from copy disappears.

Answer 7

Here's another way:

cd. > filename

Answer 8

You could also use

echo. 2>foo

The debug output for echo. will almost definitely be empty :)

HTH, -Craig