Remove content from text file using command line

Question

I have already done many searches and have not found a clear way to do it. there are many variations of how people are removing contents in a text file but not the way I need it to be done.

I have a watch folder that has about 22 text file dropped every 30 minutes. I need to be able to run something that deletes the first 3000 lines in those text file.

I have other task performing to those files and using task scheduler to trigger batch files at a certain time.

So running it on schedule is no issue.

My issue is I cannot find a way to remove 3000 lines from each of the text files, without copying, deleting or changing the other content.

Does anyone know how to remove 3000 lines from a text file? I can get the loop to find all the text file no issue, jut doesn't know the command to remove lines.

Answer 1

I would just use powershell for this. This example removes the first 3000 lines from a single test.txt file.

$file = "test.txt"
$remo = get-content $file
$remo[3000..$remo.count] | set-content $file

If you feel comfortable with batch file, you could just loop the above powershell into batch to do this to each file..