Re: Odd behavior with various (q) array modifiers and non-printable characters (backspace, newline)

[Ray Andrews <rayandrews@eastlink.ca>]

On 2021-08-11 5:22 p.m., Bart Schaefer wrote:
> On Wed, Aug 11, 2021 at 4:25 PM Zach Riggle <zachriggle@gmail.com> wrote:
>> TLDR 2: I also learned that (q+) is my new favorite, and my code
>> should use "command echo" to avoid the above behavior.
I'd like to add the anecdotal remark that there were many situations 
where I thought I'd solved a problem with (q) or (Q) or (q+) and it 
turned out that these things only made more trouble in the end. Better 
solutions were to be found that didn't involve the Q continuum.  Being 
only semi-literate as I am, sometimes the mystery never did get solved 
-- I had some issue, (q...) seemed the fix it, then (q...) started 
breaking things, I remove the (q...) and it seems like there never was a 
problem to begin with, probably because I made some other change that 
obviated the original issue.   If Zach's experience is like mine he 
might end up being weary of the Q himself.

One of my astronomy packages creates this helpful directory and file:


       4096 [2021-01-01--14:03] Sky above 49°30'N 123°30'W at Sun 2020 
Dec 20 20 26_files/
       22213 [2020-12-20--12:27] Sky above 49°30'N 123°30'W at Sun 2020 
Dec 20 20 26.html

... and I always throw any change I make in one of my functions at those 
files as torture tests because any change is likely to break when it 
encounters those -- the internal quote or the special characters or the 
spaces are ultra fragile and only the exactly perfect code handles all 
of them at the same time.  Q seemed to help at times, but again, it 
often was a false friend.  I'm still far from clear on how you 
absolutely, perfectly protect *any* filename or string every time even 
on Mondays and even if it's a filename that the Devil himself wouldn't 
make ... but I get closer all the time.  Zach will get the right advice 
tho and not from me.