discuss: GNU Linux Command Line Tools Summary Ready for inclusion
Subject:
Re: GNU Linux Command Line Tools Summary Ready for inclusion
From:
"Jaroslaw Fedevych (UALUG" ####@####.####
Date:
25 Feb 2005 11:49:24 -0000
Message-Id: <20050225114921.GA31988@fly.osdn.org.ua>
On Fri, Feb 25, 2005 at 11:13:14AM +0000, David Holroyd wrote:
> On Fri, Feb 25, 2005 at 10:43:18AM +1100, Gareth Anderson wrote:
> > > Section 6.2
> > >
> > > [[
> > > tr [A-Z] [a-z] < fileName.txt > fileNameNew.txt
> > > ]]
> > >
> > > This example won't work because the arguments of tr are not
> > > quoted.
> >
> > Then why does it work on my Mandrake, 9.1 and 10.1 box?
>
> Why? Luck...
>
> dave@dunce:~$ echo FOO | tr [A-Z] [a-z]
> foo
> dave@dunce:~$ touch A
> dave@dunce:~$ echo FOO | tr [A-Z] [a-z]
> FOO
>
It will work because shell performs expansion. You get another
shell, to which [ ] has other meaning, and the command works no more.
In FreeBSD man page for tr its arguments which include [ and ] are
always quoted. Why? Try
echo foo | tr [:lower:] [:upper:]
and
echo foo | tr "[:lower:]" "[:upper:]"
and see it for yourself.
--
X windows: Warn your friends about it.
