Subject: Re: VERY strange command-line syntax for 'df -t'
To: NetBSD Userlevel Technical Discussion List <tech-userlevel@NetBSD.ORG>
From: Greg A. Woods <>
List: tech-userlevel
Date: 04/08/2002 13:08:33
[ On Monday, April 8, 2002 at 11:51:11 (+0100), David Laight wrote: ]
> Subject: Re: VERY strange command-line syntax for 'df -t'
> On Sun, Apr 07, 2002 at 06:52:46PM -0400, Greg A. Woods wrote:
> > The second alternative, with the first variation is probably the best
> > because it is completely compatible with the current syntax.  I.e. just
> > allow 'no' to prefix each item in the list:
> > 
> > 	-t nonfs,[no]mfs
> 	-t nonfs,mfs
> Does this request actualy make sense?

Do you mean within the context of my proposal, or in the current
implementation?  I.e. do you really mean:

	-t mfs,nonfs

> Since file systems types don't overlap, if you explicitly include
> one file systems type you implicitly exclude all others.

I discussed this already, but perhaps not in enough detail.

What about if other command-line operands imply a default list of
filesystems which is a subset of the complete list?

What about this documented behaviour (from df(8))?

      If a file system is given on the command line that is not of the
      specified type, a warning is issued and no information is given on
      that file system.

Under my proposal I would expect your example to generate a warning if
no "mfs" filesystems are mounted (and no files are specified on the
command line).

								Greg A. Woods

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