On Thu, Jun 06, 2019 at 11:33:56AM +1000, David wrote: > Regarding $((...)) when Chet refers above to "the expression between the > parens" > he means whatever is between the parentheses, in this case the three dots. > > If I understand correctly, Chet is saying there that $((...)) is > parsed as if it was written > $(("...")) and therefore any single quotes inside the parentheses are > not special.
But... On Tue, Jun 04, 2019 at 09:24:27AM -0400, Greg Wooledge wrote: > wooledg:~$ a=(foo bar baz) > wooledg:~$ i='$(date >&2)' > wooledg:~$ echo $(( a[$i] )) > Tue 04 Jun 2019 09:23:28 AM EDT > 0 > wooledg:~$ echo $(( 'a[$i]' )) > bash: 'a[$(date >&2)]' : syntax error: operand expected (error token is > "'a[$(date >&2)]' ") I definitely got different results when I added single quotes.