On Fri, Mar 16, 2018 at 02:59:53PM -0400, Greg Wooledge wrote: > On Fri, Mar 16, 2018 at 02:06:09PM -0400, Boruch Baum wrote: > > echo $IFS |xxd > > 00000000: 0a > > This command will never reveal any information, period.
I was slightly mistaken there. It actually reveals the number of non-IFS-whitespace characters in IFS (sometimes). You can calculate this by adding 1 to the number of spaces that echo puts in between the null arguments that it receives. Unless, of course, echo prints zero space characters -- in which case you can't tell whether it received zero arguments, or one null argument, as the resulting output is the same in both cases. https://mywiki.wooledge.org/Quotes wooledg:~$ IFS=qqqq wooledg:~$ args $IFS 4 args: <> <> <> <> wooledg:~$ echo $IFS | od -An -tx1 20 20 20 0a echo wrote three space characters, so we can conclude that IFS had 4 non-IFS-whitespace characters. We cannot conclude anything more, unless I've missed another thing.
