Re: ITP dos2unix 5.2.1-1

[Christian Franke <Christian dot Franke at t-online dot de>]

Christopher Faylor wrote:
> On Wed, Mar 16, 2011 at 04:05:17PM -0400, Charles Wilson wrote:
>    
> > On 3/16/2011 3:32 PM, Christopher Faylor wrote:
> >      
> > > On Wed, Mar 16, 2011 at 08:29:51PM +0100, Christian Franke wrote:
> > >        
> > > > An alternative would be to modify cygutils+dos2unix packages such that
> > > > the user can select the flavor of dos2unix/unix2dos commands with
> > > > /usr/sbin/alternatives. If cygutils is the default if installed this
> > > > should not break anything.
> > > >          
> > Except you would no longer be able to run dos2unix/unix2dos/d2u/u2d from
> > a non-cygwin context, such as 'naked' cmd.exe or some IDE like Eclipse.
> >
> >      
> > > Hey, good idea, assuming that Chuck is amenable.  I'd be happy to just
> > > let the package in given that proviso if so.
> > >        
> > Uh, let's think about that a minute.
> >
> > cygutils is pulled in as part of Base (cygutils is not in the Base
> > category, but it is required by a packages that is: cygwin-doc).  Adding
> > alternatives as a dep of cygutils would then make alternatives an
> > implicit part of Base.  alternatives itself brings in no other unsavory
> > dependencies.
> >
> > This would be a change, since although alternatives is used by some very
> > common packages [vim, automake], it's not in the default Base-"only"
> > (actually, Base+requirements) installation.
> >
> > It also means that cygwin's dos2unix could no longer be executed from a
> > non-cygwin context, because of the symlinks.
> > ...
> >      
> Ah, right.
>
> I didn't get that Eric was referring to this scenario but, regardless,
> I should have remembered that alternatives means using symlinks.  Given
> the use that d2u is put, I don't think we want to make it a symlink.
>
>    

Agree, symlinks should be avoided.

Another alternative: Keep hard links as is if cygutils is installed 
only. If dos2unix is also installed assume that user opted-in to replace 
the dos2unix and unix2dos commands (and only these) with the linux 
variant. Undo this change if dos2unix is uninstalled.

This may be possible to handle this in the postinstall/preremove scripts 
of both packages as follows (dos2unix case only, not tested):

cygutils*.tar: remove dosunix2.exe but keep d2u.exe.

dosunix*.tar: Install dos2unix.exe as e.g. dos2unix-linux.exe

# /etc/postinstall/cygutils.sh:
if cmp -s /usr/bin/dos2unix-linux.exe /usr/bin/dos2unix.exe; then :; else
  ln -f /usr/bin/conv.exe /usr/bin/dos2unix.exe
fi

# /etc/preremove/cygutils.sh:
if cmp -s /usr/bin/conv.exe /usr/bin/dos2unix.exe; then
  rm -f /usr/bin/dos2unix.exe
fi

# /etc/postinstall/dos2unix.sh:
ln -f /usr/bin/dos2unix-linux.exe /usr/bin/dos2unix.exe

# /etc/preremove/dos2unix.sh:
if cmp -s /usr/bin/dos2unix-linux.exe /usr/bin/dos2unix.exe; then
  if test -f /usr/bin/conv.exe; then
    ln -f /usr/bin/conv.exe /usr/bin/dos2unix.exe
  else
    rm -f /usr/bin/dos2unix.exe
  fi
fi


Christian