Re: mmotm 2019-07-04-15-01 uploaded (gpu/drm/i915/oa/)

[Andrew Morton]

On Thu, 04 Jul 2019 22:22:41 -0700 Joe Perches <joe@xxxxxxxxxxx> wrote:

> > So when comparing a zero-length file with a non-existent file, diff
> > produces no output.
> 
> Why use the -N option ?
> 
> $ diff --help
> [...]
>   -N, --new-file                  treat absent files as empty
> 
> otherwise
> 
> $ cd $(mktemp -d -p .)
> $ touch x
> $ diff -u x y
> diff: y: No such file or directory

Without -N diff fails and exits with an error.  -N does what's desired
as long as the non-missing file isn't empty.