Re: Feature Request: scanf-like parsing

[Greg Wooledge]

On Mon, Jan 25, 2021 at 06:47:36PM +0200, Oğuz wrote:
> 25 Ocak 2021 Pazartesi tarihinde Chet Ramey <chet.ramey@case.edu> yazdı:
> > declare -A copy
> > eval copy=( "${assoc[@]@K}" )
> 
> So many reputable people contributed to the demonization of `eval' that I
> don't think I can convince anyone that there's nothing wrong with it
> anymore.

It's a tricky thing to deal with.  Eli referenced my wiki, which has a
page dedicated to it, with contributions from many different authors.
The resulting quasi-consensus is complex and perhaps even a little
bit self-contradictory as a result.

You'll want to use eval only when it's absolutely necessary, and only when
it's safe.  If bash's @K feature is designed to be fed to eval, then we
can assume it's safe.  It becomes one of the very small number of
green-lighted cases where eval is OK.

The problem with eval is that for every OK usage, there are a thousand
incorrect and dangerous uses.  Avoid those, by being absolutely sure
you know what you're doing, and why you're doing it.