Re: trap question

[Ray Andrews <rayandrews@xxxxxxxxxxx>]

On 2022-11-25 20:50, Bart Schaefer wrote:

> No,
>       it should not be on. I was giving an example of an error where an
> exit trap would be tripped, not implying that you want that condition
> to be an error.  If a command returning false is an error you should
> be explicitly handling that and doing a normal return/exit.
>
>

Eventually sure, but when things are unstable it's at least nice to have zcurses powered down under control, no?  I'll set that option and see what transpires. 

	Lawrence:

	It's not a special case, just like "eval" isn't a special case.

I'd put it the other way: trap and eval are both special cases, no?  Surely the general rule is that nothing is ever expanded within single quotes?

Now, if you use single quotes instead of double quotes, the first argument of the trap command expands to the string  [[ $var == '0' ]] && echo trap: var is: $var, which looks like a much more interesting command to execute when the EXIT trap triggers ;-)

Philippe

Ok, that makes nothing but sense.  The single quotes do what single quotes do, *but* there is also the intuitive way that the trap is always 'in reserve' -- it never does anything when/where written, only when sprung, so at that time the quotes are gone and the variable expands to it's value in real time.  Got it.  It's sorta like compiled code.