At Sun, 19 Jan 2020 14:22:29 -0700, Grant Taylor via TUHS <tuhs(a)minnie.tuhs.org>
wrote:
Subject: [TUHS] Shell Level...
Have you ever used shell level, $SHLVL, in your weekly ~> daily use of Unix?
I invented my own variant, $LEV, for Ksh, starting before 1993, probably
when I first started using DMD-5620 terminals and layers, though
possibly slightly before that when I first started using Ksh (about 1989
when I bought a used ATT3B2/400 for home use). I used my own $LEV in my
prompt (or the window title, if using a windowing system) just to remind
me if I'd started a sub-shell for some reason, such as in order to
preserve my current working directory and environment.
Early Ksh didn't have $SHLVL, and it's not universal (i.e. POSIX), so
I've never really used $SHLVL itself (though I have very recently added
a hook to set my $LEV from it IFF it is available).
See
https://github.com/robohack/dotfiles :-)
--
Greg A. Woods <gwoods(a)acm.org>
Kelowna, BC +1 250 762-7675 RoboHack <woods(a)robohack.ca>
Planix, Inc. <woods(a)planix.com> Avoncote Farms <woods(a)avoncote.ca>