[ubuntu-za] Script error

[Neil Muller]

On Tue, Apr 14, 2009 at 03:37:17PM +0200, Neil Muller wrote:
> On Tue, Apr 14, 2009 at 03:03:09PM +0200, Walter Leibbrandt wrote:
> > ... Or zero.
> > 
> > The following seems to always echo 1, ie. -f returns true if no 
> > parameters are specified:
> > if [ -f ]; then echo 1; else echo 0; fi
> 0
> $ unset UNDEFINED # UNDEFINED is null
> $ [ -f $UNDEFINED ] ; echo $? # still test for existance, even though null
> 1

Which is of course completely and utterly wrong - if UNDEFINED is null,
this evaluates to  [ -f ], and succeeds. (I ran the above command in the
wrond shell, where UNDEFINED was defined (don't ask), and got the wrong
results).

-- 
Neil Muller  email: neil at dip.sun.ac.za 

Division Applied Mathematics, Department of Mathematical Sciences
University of Stellenbosch