desired diff feature: show common lines

Hi there

I would sometimes like see the common lines of two files
only. I haven't 
been able to make diff show me that, might not be its
purpose.

Would it be easily (enough) to add that functionality to
diff?

I might miss the existence of some other tools. Obviously,
there might 
not be enough demand for that feature anyway.

Thanks for your time and work!

Chris

Chris Konig Beatty wrote:
> I would sometimes like see the common lines of two
files only. I haven't 
> been able to make diff show me that, might not be its
purpose.

As far as I know 'diff' doesn't support that functionality. 
You
should look at the 'sdiff' program.  It will show
differences side by
side and effectively shows the lines that are the same.

> Would it be easily (enough) to add that functionality
to diff?

It really isn't the job of diff to do this.

> I might miss the existence of some other tools.
Obviously, there might 
> not be enough demand for that feature anyway.

If the files are sorted the 'comm' program is designed to do
this.

There are a number of tools that will show the differences
between two
files side by side.  Here are a few.

  emacs-emerge
  meld
  mgdiff
  sdiff
  tkdiff
  xxdiff

Bob