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Re: Return from function depending on number of parameters

From: Lawrence Velázquez
Subject: Re: Return from function depending on number of parameters
Date: Sat, 4 Jul 2020 12:23:45 -0400

> On Jul 4, 2020, at 8:12 AM, pepa65 <pepa65@passchier.net> wrote:
> On 04/07/2020 04.39, Lawrence Velázquez wrote:
>> It might tell you something that $[...] is not even mentioned in
>> the man page for bash 3.2.57, which is decidedly not the current
>> version.
> About that, is it for sure that $[] is going to be obsoleted/removed in
> the future?

Only Chet knows for sure, but "obsolete" need not mean "removed".
Given how thoroughly it's been memory-holed, $[...] is about as
obsolete as it can get. Removing it would break a lot of old scripts,

> I happened to use it recently


> and thought it was more readable than $(()) and caused less visual
> clutter. Any reason $(()) was preferred?

Quoting Chet liberally from

> On 4/7/12 4:45 PM, Linda Walsh wrote:
>> In modifying some released code on my distro,    I ran into the extensive use
>> of   $[arith]  as a means for returning arithmetic evaluations of the
>> expression.
>> I vaguely remember something like that from years ago, but never see any
>> reference to
>> it -- yet it works, and old code seems to rely on it -- and
>> "$[(1+2)/3]"  looks cleaner than "$(((1+2)/3))".  So what's up with that?
> It dates from Posix circa 1990 (1003.2d9, of which I've lost my paper
> copy).  I implemented it after the Berkeley guys, mostly Marc
> Teitelbaum, put it into Posix.  It ended up getting dropped in favor
> of the ksh $((...)) expansion, at which point everyone deprecated the
> old $[...].  I removed it from the manual sometime later, but it still
> works as it always has.


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