Recently got a cheap 128 GB SSD to see how BSD would run on my main machine, and this weekend threw FreeBSD on it. I'm sending this toot from the working system, and aside from the general configuration joy of being an Unix nerd, finding almost everything I need to know in the FreeBSD Handbook is a great perk on the second joy: reading docs and being able to flow acting on them.
After a while trying to understand if either ksh or zsh provided a way to prevent taking strings and undefined variables as 0 when doing arithmetic evaluation, there seems to be no feature specifically for it, sadly.
Closest is using set -o nounset (ksh) and setopt no_unset (zsh) to prevent undefined variables from evaluating to zero. If a "string" contains only numbers, a dot and whitespace, it will be treated as a number. Also, if it only contains the name of any other variable and whitespace, it evaluates to that.
Not that I expected shell languages to provide accurate arithmetic.
As a bonus though, it was cool learning about ksh's compound variables, force_float option and especially discipline functions.
After a while trying to understand if either ksh or zsh provided a way to prevent taking strings and undefined variables as 0 when doing arithmetic evaluation, there seems to be no feature specifically for it, sadly.
Closest is using set -o nounset (ksh) and setopt no_unset (zsh) to prevent undefined variables from evaluating to zero. If a "string" contains only numbers, a dot and whitespace, it will be treated as a number. Also, if it only contains the name of any other variable and whitespace,...
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