Fun w/ test :)

Cristian Ionescu-Idbohrn cristian.ionescu-idbohrn at axis.com
Tue Jul 22 13:10:29 UTC 2008


On Tue, 22 Jul 2008, Denys Vlasenko wrote:

> So, now, do you see why x"str" trick is actually not so silly?

We're now debating:

  test EXPRESSION

which differs from:

  [ EXPRESSION ]

Still...

> On Thursday 15 May 2008 02:20, Paul Fox wrote:
> >  > You're talking again of som general case.  In this particular case:
> >  >
> >  >   [ x"$foo" != x ]

The above is silly, but:

  test x"$foo" != x

is not that silly, but still silly :), as:

  test "$foo"

or:

  test -z "$foo"

or:

  ! test "$foo"

should cover most cases.

> >  > it's totally useless quoting an empty string after the 'x' on the
> >  > right side of the condition.
> >
> >
> > sigh.  why would you write this at all?  either say what you
> > mean, and write:
> >     [ "$foo" != "" ]

The above is silly too.

> > or say it in the usual shell idiom and write:
> >     [ "$foo" ]

Above is ok.

  test "$foo"

is ok too.

> > or
> >     [ -n "$foo" ]

Above or:

  test -n "$foo"

waste 3 bytes to no purpose, so they're silly.

> > but this
> >     [ x"$foo" != x ]
> > or this
> >     [ x"$foo" != x"" ]
> >
> > are just silly.

Yes, and the 2nd form is sillier then the 1st :)
But, on the other hand, I might be totally wrong about all of it :)


Cheers,

-- 
Cristian



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