Re: protect spaces and/or globs

[Ray Andrews <rayandrews@eastlink.ca>]

On 2021-02-11 9:19 a.m., Lawrence Velázquez wrote:
>
> Why are you still accreting grepargs like this? Peter has already
> shown you how to do this.
>
> 	grepargs=("$@")
>
> Unless your actual code actually modifies the args before adding
> them to the array?
Not modified but the ordering is different so I hafta grab them one at a 
time.
Good point tho, all else equal I see that Peter's method is better.
> 	[...]
>
> 	% pat='on the current' foo='i,2,light edit' bar='i,1,old stable'
> 	% grep_wrapper $pat $foo $bar
>
> 	what should be going to history:
> 	grep --color=always -i -- 'on the current' 'i,2,light edit' 'i,1,old stable'
Yes, point made.  I know that if I want something expanded I don't 
single quote it. But indeed
I shouldn't say 'exactly as typed' because I know that variables will be 
expanded.

> 	[...]
>
> A ${(q-)foo} expansion basically re-quotes the value of foo so
> it works correctly with eval, in whatever way is requested. It
> doesn't know the value's origins.
That's a subtle but important point.  I could think of it as 
'protection' but then
how did the variable expand?  As you say it must be seen as re-quoting.  
Thanks
for catching it.
> That's not how quoting works. Quote levels don't nest to produce
> some kind of super-quoting. You're misinterpreting the results of
> your experimentation.
>
> 	% foo='a b c'
> 	% print -r 'protected: $foo'
> 	protected: $foo
> 	% print -r "'not protected: $foo'"
> 	'not protected: a b c'
>
> The double quotes do protect the single quotes from being interpreted
> by the shell, but they also permit expansions.
That is a critical point.  You know, it is so easy to think you've 'got 
it' when you don't.
I'm going to take the above and write it to a sticky note a stick it to 
my desk.  Very
insightful of you to realize that I'm not seeing things right, many thanks.