From: mascheck@in-ulm.de (Sven Mascheck)
Subject: [TUHS] Shell control through external commands
Date: Tue, 13 Sep 2016 02:17:55 +0200 [thread overview]
Message-ID: <20160913001755.GA266082@lisa.in-ulm.de> (raw)
In-Reply-To: <57d6a482.xj2/kMA3y0vR9uVo%schily@schily.net>
On Mon, Sep 12, 2016 at 02:50:10PM +0200, Joerg Schilling wrote:
> > > The colon was introduced by AT&T around 1983.
> >
> > It's a builtin in the v7 Bourne shell - see SYSNULL in msg.c (which
> > has the command name table) and in xec.c (which has the implementation)
>
> You are missinterpeting things.
>
> The colon in line one as a hint to a modified csh to call the Bourne Shell
> first appeared around 1983.
I'm still confused (you're short with context): what does "introduced by AT&T" mean?
I only know the #-hacked csh from 2BSD+ ('79), and the #-hacked sh from 3BSD+ ('80).
How would ":" as a hint in this respect show up on other systems?
BTW: academic but funny side effect of : as no-op instead of real comment:
: `echo output 1>&2`
actually writes to stderr.
Normal Wilson wrote:
> [...] A hack emerged: if csh encountered a script file, it would read the
> first character; if that was '#' it was a csh script, otherwise it handed
> off to /bin/sh.
lesser known fact: even sh was hacked on BSDs (since 3BSD) with this #-csh magic,
and also exec'ed to csh. This then co-existed with the soon coming implementation
of "#" as comment character.
-Sven
next prev parent reply other threads:[~2016-09-13 0:17 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-15 16:47 Doug McIlroy
2016-09-10 17:40 ` Dario Niedermann
2016-09-10 19:22 ` arnold
2016-09-12 8:35 ` markus schnalke
2016-09-12 9:25 ` Joerg Schilling
2016-09-12 12:41 ` Tony Finch
2016-09-12 12:50 ` Joerg Schilling
2016-09-13 0:17 ` Sven Mascheck [this message]
2016-09-13 1:45 ` Sven Mascheck
2016-09-13 9:20 ` Joerg Schilling
2016-09-12 20:12 ` Dave Horsfall
2016-09-12 21:36 ` Dave Horsfall
2016-09-10 22:43 ` Dave Horsfall
2016-09-11 1:24 ` Ron Natalie
2016-09-11 2:39 ` arnold
2016-09-11 2:41 ` Ronald Natalie
2016-09-11 4:07 ` Dave Horsfall
2016-09-11 5:01 ` arnold
2016-09-12 5:49 ` Dave Horsfall
-- strict thread matches above, loose matches on Subject: below --
2016-09-12 12:57 Norman Wilson
2016-09-12 12:56 Norman Wilson
2016-09-12 1:43 Norman Wilson
2016-09-12 9:18 ` Joerg Schilling
2016-09-12 1:31 Norman Wilson
2016-09-12 9:33 ` Joerg Schilling
2016-09-12 0:27 Doug McIlroy
2016-09-11 17:39 Doug McIlroy
2016-09-11 18:11 ` Clem Cole
2016-09-11 18:27 ` Dan Cross
2016-09-11 18:50 ` Sven Mascheck
2016-09-11 22:13 ` Random832
2016-09-10 14:57 Nemo
2016-07-15 12:27 Norman Wilson
2016-09-10 7:45 ` Dario Niedermann
2016-09-10 9:13 ` Michael Kjörling
2016-09-10 9:41 ` Joerg Schilling
2016-09-10 17:06 ` Random832
2016-09-10 17:45 ` Dario Niedermann
2016-09-10 19:53 ` Dan Cross
2016-09-10 20:02 ` Chet Ramey
2016-09-10 20:27 ` Dario Niedermann
2016-09-11 10:03 ` Diomidis Spinellis
2016-09-12 10:05 ` Jacob Goense
2016-07-15 4:29 Rudi Blom
2016-07-14 13:18 Diomidis Spinellis
2016-07-14 13:23 ` Clem Cole
2016-07-14 14:12 ` Mary Ann Horton
2016-07-14 22:36 ` Dave Horsfall
2016-07-14 22:47 ` Corey Lindsly
2016-07-14 22:49 ` Peter Jeremy
2016-07-14 23:27 ` Marc Rochkind
2016-07-15 10:13 ` Joerg Schilling
[not found] ` <CAH_OBieVFzPn93L8=_fmbUycZ7UmYdXiopC0vgei6RGDZp0mHw@mail.gmail.com>
[not found] ` <CAH_OBie_6gFy+BqkCMj+sr0NqTMNOQxvgWf6SQnHMJpn7DAytA@mail.gmail.com>
2016-07-14 23:56 ` shawn wilson
2016-07-15 1:04 ` Dave Horsfall
2016-07-15 1:22 ` Steve Nickolas
2016-07-15 2:25 ` arnold
2016-07-16 6:26 ` Dave Horsfall
2016-07-15 2:25 ` Random832
2016-07-15 3:59 ` Dave Horsfall
2016-07-15 4:09 ` Random832
2016-07-15 13:55 ` Chet Ramey
2016-07-14 23:10 ` Ronald Natalie
2016-07-15 1:41 ` Nemo
2016-07-15 9:00 ` Tony Finch
2016-07-14 14:11 ` schoedel
2016-07-14 14:38 ` Diomidis Spinellis
2016-07-14 15:46 ` John Cowan
2016-07-14 16:30 ` Random832
2016-07-14 22:32 ` Dave Horsfall
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