How to clear the contents of a file from the command line?

Question

I have a log file that has a bunch of stuff in it that I don't need anymore. I want to clear the contents.

I know how to print the contents to the screen:

cat file.log

I know how to edit the file, line-by-line:

nano file.log

But I don't want to delete each line one at a time. Is there a way to do it in one command without destroying the file to do it?

Solution:

This worked for me:

> file.log

Answer 1

In bash, just

> filename

will do.

This will leave you with an empty file filename.

Answer 2

you could always type this:

echo "" > file.log

not >> as this will append.

Answer 3

$ rm file.log; touch file.log

or

$ cat > file.log

followed by control-d.

or...or...or...

Ah. Here is a single command version:

$ dd if=/dev/null of=file.log

Answer 4

One line at a time?

Try vi(m), the lovely text editor that can do anything. In this case, navigate to a line, press d (for delete), and d again (for line).