How to delete content from a text file using windows batch script

Question

I have a demo.txt file. I need to delete content in that file using a batch file. Please tell me the command to delete content for demo.txt file.

Answer 1

This seems most intuitive to me:

copy /y nul demo.txt

NOTE: Unfortunately, like the other methods provided here, this fails if demo.txt is currently in use by another process. In such a case it is sometimes possible to open the file in a text editor and delete all the contents, even though the file is in use. I don't know of a way to do this from the command line.

Answer 2

If the file is used by another application command prompt redirection may fail (as it requires more file access then necessary). In that case you can use powershell:

PS> Set-Content file.txt $null

Note: do not expect that it will allow access to exclusively opened files.

Answer 3

break>demo.txt

Try this.it will set an empty file on the place of demo.txt. As break is internal command that does nothing it should be pretty fast.Also the break command can produce output only with /? argument so this makes this method pretty robust.

Answer 4

Command Prompt:

1. break>c:\'file directory'\demo.txt

PowerShell:

2. Clear-Content c:\'file directory'\demo.txt

Answer 5

type nul > demo.txt

works and also works in JPSoft's TakeCommand TCC.EXE command shell (where "break" will output "BREAK is ON" rather than nothing as it does in Microsoft CMD.EXE)

The general idea is to find a command that outputs Nothing and redirect that to the file using >