Hi, On 24/04/17 10:24, David via luv-main wrote:
On 23 April 2017 at 15:35, Andrew McGlashan via luv-main <luv-main@luv.asn.au> wrote:
Hi,
On 23/04/17 14:42, David via luv-main wrote:
If you insist on using 'set -e', you could do this to disable exitstatus checking on arithmetic contexts:
set -eu i=0 for a in a b c do echo "${a}" ((i++)) || true done
Yes, that would be the cleanest way to solve this. Thanks.
I disagree, I think it is a bit hackish, but it is a universal solution to the collision of trying to use 'set -e' together with unknown arithmetic results that might include zero, so I thought it was worth adding to the discussion.
But in your example use-case, the arithmetic results are entirely predictable.
In the message I sent before the one above, I gave what seemed to me the cleanest way to do what you originally asked, using pre-increment as I suggested in my first reply:
Yes, I did see that and I tried it out; pre-increment gives problems just the same as post-increment. So that wasn't a solution. There is obvious debate on both sides and I can understand the various arguments for both points -- using set -x or not AND using the ((i++)) construct or not, To me, arithmetic math with the use of the double round brackets is, due to the other use of the construct, a mistake to have been implemented that way. Using "((i++)) || true" allows me to say, I don't care if the arithmetic result is zero, I am handling the condition for loop exit outside of that result and the actual return from the ((i++)) is totally irrelevant. The other alternative that was good was this one: for ((i=0; i<${#array[@]}, i++)) do ... done Anyway, I am using the C construct with the for loop now as it is slightly better IMHO. But I would have no problem using the other solution of: ((i++)) || true - when it suits... Thanks and Cheers AndrewM