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From: Stephane Chazelas <stephane@chazelas.org>
To: Bart Schaefer <schaefer@brasslantern.com>
Cc: Zsh hackers list <zsh-workers@zsh.org>
Subject: $SHLVL origin (was: $PPID not updated when the PPID changes (parent killed))
Date: Tue, 18 May 2021 19:50:39 +0100	[thread overview]
Message-ID: <20210518185039.7zo76vofxrn6qqqd@chazelas.org> (raw)
In-Reply-To: <CAH+w=7YR5OagGbTWT1fuQfDJvrZBekBgZUQKh6kfWe1TtW-aQQ@mail.gmail.com>

2021-05-18 11:12:54 -0700, Bart Schaefer:
> On Tue, May 18, 2021 at 11:06 AM Stephane Chazelas
> <stephane@chazelas.org> wrote:
> >
> > $SHLVL (a (t)csh thing IIRC, not handled by all shells)
> 
> Bash has it, for sure.
[...]

I remember looking up the origin of it when we were discussing
https://www.zsh.org/mla/workers/2016/msg01574.html

It does come from tcsh in the early 80s (see
https://groups.google.com/forum/message/raw?msg=net.sources/3eER9GEdo2c/B9G1KGziIx4J
for instance).

Also supported by bash, ksh93, fish, zsh and yash (implement in
startup file as shell code only for interactive instances
there), but not much else and not in POSIX.

-- 
Stephane


  reply	other threads:[~2021-05-18 18:52 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-16 15:24 $PPID not updated when the PPID changes (parent killed) Vincent Lefevre
2021-05-16 18:37 ` Bart Schaefer
2021-05-17 20:26   ` Vincent Lefevre
2021-05-17 21:00     ` Bart Schaefer
2021-05-17 22:27       ` Phil Pennock
2021-05-17 23:15         ` Bart Schaefer
2021-05-18  0:30           ` Phil Pennock
2021-05-18  1:14             ` Bart Schaefer
2021-05-18  8:28             ` Vincent Lefevre
2021-05-18  8:15           ` Vincent Lefevre
2021-05-18 14:53             ` Bart Schaefer
2021-05-19  4:25               ` Bart Schaefer
2021-07-18 23:10                 ` Lawrence Velázquez
2021-05-18 15:18           ` Mikael Magnusson
2021-05-18 16:14             ` Peter Stephenson
2021-05-18 18:20               ` Bart Schaefer
2021-05-18 17:37           ` Martijn Dekker
2021-05-18 18:08             ` Bart Schaefer
2021-05-18 19:40               ` Martijn Dekker
2021-05-18 18:06           ` Stephane Chazelas
2021-05-18 18:12             ` Bart Schaefer
2021-05-18 18:50               ` Stephane Chazelas [this message]
2021-05-18 15:56         ` Stephane Chazelas

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