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From: Stephane Chazelas <stephane@chazelas.org>
To: Roman Perepelitsa <roman.perepelitsa@gmail.com>
Cc: Ray Andrews <rayandrews@eastlink.ca>, zsh-users@zsh.org
Subject: Re: optimal expansions?
Date: Sun, 21 Apr 2024 17:14:40 +0100	[thread overview]
Message-ID: <20240421161440.jicmznwxqb6pz2fg@chazelas.org> (raw)
In-Reply-To: <CAN=4vMrmUdgGuhDZjrrhCvQZaiSyCMPm0yAZMM0DYUGf6efDjg@mail.gmail.com>

2024-04-21 16:19:24 +0200, Roman Perepelitsa:
> On Sun, Apr 21, 2024 at 4:10 PM Ray Andrews <rayandrews@eastlink.ca> wrote:
> >
> > On 2024-04-21 05:23, Roman Perepelitsa wrote:
> >
> > Seems we want '-r' most of the time.  And the '--' should always be there.
> >
> > The missing `-r` is a bug. It should be there. The `--` in this case
> > is optional because the positional argument cannot start with a dash.
> >
> > But the '--' is good standard practice, yes?
> 
> You can call it that. It's one of those standard practices that I
> don't follow, but if you find the trade-off palatable, go for it.
[...]

I would urge you to reconsider, especially for the "print"
built-in of zsh.

print $external_data

or

print -r $external_data

is a command injection vulnerability.

$ external_data='-vpsvar[1$(reboot)]' zsh -c 'print -r $external_data'
System going down for reboot now.

(I have actually singled-out zsh's print for that at
https://unix.stackexchange.com/questions/11376/what-does-double-dash-double-hyphen-mean/590210#590210)

-- 
Stephane


  reply	other threads:[~2024-04-21 16:15 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-19 19:22 Ray Andrews
2024-04-19 20:40 ` Lawrence Velázquez
2024-04-19 23:25   ` Ray Andrews
2024-04-20  7:42 ` Roman Perepelitsa
2024-04-20 14:23   ` Ray Andrews
2024-04-20 22:54     ` Lawrence Velázquez
2024-04-20 23:59       ` Ray Andrews
2024-04-21 12:23     ` Roman Perepelitsa
2024-04-21 14:09       ` Ray Andrews
2024-04-21 14:19         ` Roman Perepelitsa
2024-04-21 16:14           ` Stephane Chazelas [this message]
2024-04-21 17:39             ` Roman Perepelitsa
2024-04-21 20:13               ` Stephane Chazelas
2024-04-21 20:46                 ` Lawrence Velázquez

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