How to zero out a file in tcsh?

[jj at lcs.mit.edu (John Jannotti)]

Jerry Feldman <gaf at h0020780e341c.ne.client2.attbi.com> writes:
> On Thu, 6 Feb 2003 22:29:15 -0500
> Derek Martin <blu at sophic.org> wrote:
> 
> > One method to do this regardless of how your shell handles redirection
> > and what flavor of echo you have is this:
> > 
> >   rm filename; touch filename
> I fully concur with Derek. This is full portable accross all versions of
> Unix and Linux. As mentioned in the other posts, echo, while a shell
> builtin may have different behavior depending on the shell. 

But it doesn't do the same thing.  The other examples truncate the existing
file, this doesn't.  It's possible this makes a difference.  One of the
reasons you might be doing this is to reclaim disk space.  If a process has
the file open, truncating it still reclaims the space, deleting it doesn't.

Or, perhaps you know that something is doing the equivalent of "tail -f" on
the file, and another process is appending to it.  If you delete and
recreate, those processes are not talking to each other any more.

I think "cat > filename", then ^d is probably the shortest portable
way. (or echo -n > filename is you're not interactive).

  jj