Re: [Help-bash] storing a command in a variable

[lxnf98mm]

On Fri, 12 Apr 2013, Dan Douglas wrote:

> On Friday, April 12, 2013 01:14:12 PM address@hidden wrote:
> > Often I do something like
> >
> > cmd="command arg" echo "${cmd}" >>my_log eval "${cmd}" 2>&1 >>my_log
> >
> > and many times I have read on this list that storing a command in a variable
> > is a bad thing to do What is a better/safer way of doing this
> >
> > Richard
>
> This is perfectly correct if the value of "cmd" is correct shell code and if
> you only use it together with eval. By "don't store a command in a variable",
> what people usually mean is don't do this:
>
>         myCmd='someCmd -o foo --arg my\ file'
>         $myCmd # This is dumb and will fail.
>
> This is smashing arguments into a string and then attempting to split
> them apart using word splitting, which is completely different than eval.
>
> Of course, there are many gotchas with eval. Aside from the usual issues, if
> all else is correct, the biggest problem is that eval != lambda. You don't
> bundle together an environment with the string (closure) so of course whatever
> it does is entirely dependent on the context in which the string gets eval'd.

Yes, there have been times I could not get eval to work because the command was 
too complex an my knowledge to weak
My main objective is CYA, "Cover Your A##"
When not if something gets screwed up at least I have a chance of finding what 
caused it

Richard