Re: Dependencies on directories on NTFS volumes

[Ken Smith]

On Sat, Mar 26, 2005 at 07:02:50PM +0100, Casper Hornstrup wrote:
>
> > -----Original Message-----
> > From: Paul Smith [mailto:address@hidden On Behalf Of Paul D. Smith
> > Sent: 26. marts 2005 16:48
> > To: Casper Hornstrup
> > Cc: address@hidden
> > Subject: RE: Dependencies on directories on NTFS volumes
> > 
[clip]
> > An alternative is to use order-only prerequisites to get the directories
> > created; since they're order-only they won't cause the targets to be
> > rebuilt.
> 
> I don't understand this.

Order-only prerequisites are only checked for existence and not newness
to determine if a dependency requires an update.  For a more fulfilling
explanation, please see:

http://www.gnu.org/software/make/manual/html_mono/make.html#SEC29

And here is an example usecase.

subdir/somefile: somefile.src | subdir
        cp somefile.src subdir/somefile

subdir: 
        mkdir -p subdir

If you modify the contents of the subdirectory `subdir', it won't result
in subdir/somefile being rebuilt.

  Ken