Re: Strange behavior of IFS?

[Greg Wooledge]

On Thu, Apr 15, 2010 at 09:58:42PM +0800, Clark J. Wang wrote:
> # cat foo.sh
> string=aa:bb:cc
> oldIFS=$IFS
> IFS=:
> for i in "$string"; do
>     echo $i
> done
> IFS=$oldIFS
> # bash foo.sh
> aa bb cc
> #
> 
> I don't understand why the $string was still splitted into words since
> it's double quoted. Anyone can give a reasonable explanation?

It was not split when you double quoted it.  It was split when you failed
to quote it in the echo command.

$ string=aa:bb:cc; oIFS=$IFS; IFS=:  
$ for i in "$string"; do printf "<%s> " "$i"; done; echo
<aa:bb:cc> 

The loop iterates one time.