I've used 'return $((!$#))' and 'return $[!$#]' to return an error if no
parameters given to function.
Tested in a bash script 'exit $((!$#)) / $[!$#]' - both work.
'echo $((!$#)) / $[!$#]' - both echo 1 when no params, 0 when any
number of params.
I'm told ( https://wiki.bash-hackers.org/scripting/obsolete ) that
$[...] is obsolete and that $((...)) should be used instead. OK so far.
However 'N=0; echo $((!$N))' gives an error at the bash prompt. 'echo
$[!$N]' echo's 1 as expected.
My question - is $[...] actually obsolete? If so, what should I use at
the bash prompt to get the same effect?
Cheers
--
Chris Elvidge
