Re: desired diff feature: show common lines

[Bob Proulx]

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