I was just wondering if this was something I should go through all my work and fix now, or can it wait until later? Is it a critical flaw in my writing? Could an inappropriate use of $! bite me sooner rather than later?

I have been tacking $! onto the end of every string I use in die and warn since I was told to use it there. I had not looked into what it was doing or how it worked. I have been using it because I was told to use it on one occasion, probably when I first used die with an open.

Please forgive me for not knowing my use of $! was not appropriate in the case in my OP. Should this be urgent, I will go through my work and make the needed changes.