Re: [PATCH 2/2] diff: add a special SYMLINK user-diff driver

From: Jeff King <peff@peff.net>
Date: Sep 22, 2010, 00:30 UTC
Message-ID: <20100922003049.GA23931@sigill.intra.peff.net>
In-Reply-To: <AANLkTi=zSPegcPNY8jr4S5qeXWHrxuC+0SY-h5EhyA+6@mail.gmail.com>

On Wed, Sep 22, 2010 at 12:12:30AM +0000, Ævar Arnfjörð Bjarmason wrote:

Show 16 quoted lines

> 2010/9/21 Jeff King <peff@peff.net>:
> > +However, it may happen that you do want to change the diff parameters
> > +specifically for symlinks. You can do that by configuring the special
> > +"SYMLINK" diff driver. For example, to add a newline to the end of
> > +the symlink contents (and suppress the usual "no newline at end of file"
> > +warning), you could configure:
> > +
> > +-----------------------------
> > +[diff "SYMLINK"]
> > +       textconv = perl -pe 's/$/\n/'
> > +-----------------------------
> 
> That'll turn every \n in the stream into \n\n, not add a newline to
> the end of the file. Don't you mean:
> 
>     perl -0666 -pe 's/$/\n/'

Yeah, it will add a newline to the end of file, but it will also double existing newlines. I wanted something short and clear so the reader could understand what was going on, and symlink paths don't generally contain an extra newline.

Just "perl -0pe 's/$/\n/'" would work, as symlink targets can't possibly have embedded NULs.

But:

> Or, more efficiently:
> 
>     perl -ple 'END { print }'

That one is even more readable, IMHO. But it isn't right. :) The automatic line-handling actually adds the missing newline, so I think it would have to be:

  perl -ple ''

-Peff