GNU bug report logs - #19243
echo comand bug

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: "Chema F. Ledesma" <hecam33 <at> gmail.com>
To: bug-coreutils <at> gnu.org
Subject: echo comand bug
Date: Mon, 1 Dec 2014 18:56:05 +0100

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Hello,

I just wanted to report a bug i think i hava found on the echo comand.

If you execute echo "!!!!!!!!!!!!!!!!!!!!!!!!" it does something strange
repeating the last command before echo comand.

I am using Ubuntu 14.04

-- 
Chema F. Ledesma

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Message #12 received at 19243-done <at> debbugs.gnu.org (full text, mbox):

From: Eric Blake <eblake <at> redhat.com>
To: "Chema F. Ledesma" <hecam33 <at> gmail.com>, 19243-done <at> debbugs.gnu.org
Subject: Re: bug#19243: echo comand bug
Date: Mon, 01 Dec 2014 11:12:51 -0700

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tag 19243 notabug
thanks

On 12/01/2014 10:56 AM, Chema F. Ledesma wrote:
> Hello,
> 
> I just wanted to report a bug i think i hava found on the echo comand.
> 
> If you execute echo "!!!!!!!!!!!!!!!!!!!!!!!!" it does something strange
> repeating the last command before echo comand.

Thanks for the report.  However, this is not a bug in 'echo', but a
feature of your shell.  At least bash has a notion of history expansion,
where double-quoted ! is a shortcut for injecting previously-typed
commands from your history into the current command invocation.  Read
'man bash' and search for "history" for details.

History expansion occurs BEFORE 'echo' sees its command line arguments.
 You'd get the same effect with ANY OTHER COMMAND, when given the same
argument.  Thus, this is not a bug in coreutils, and I'm closing this
report, although you should feel free to comment with any further questions.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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Message #15 received at 19243-done <at> debbugs.gnu.org (full text, mbox):

From: Erik Auerswald <auerswal <at> unix-ag.uni-kl.de>
To: 19243-done <at> debbugs.gnu.org, "Chema F. Ledesma" <hecam33 <at> gmail.com>
Subject: Re: bug#19243: echo comand bug
Date: Tue, 2 Dec 2014 10:28:27 +0100

Hi,

On Mon, Dec 01, 2014 at 11:12:51AM -0700, Eric Blake wrote:
> On 12/01/2014 10:56 AM, Chema F. Ledesma wrote:
> > 
> > If you execute echo "!!!!!!!!!!!!!!!!!!!!!!!!" it does something strange
> > repeating the last command before echo comand.
> 
> Thanks for the report.  However, this is not a bug in 'echo', but a
> feature of your shell.

And because of this you can use single quotes instead of double quotes to
print those exclamation marks:

$ echo '!!!!!!!!!!!!!!!!!!!!!!!!'
!!!!!!!!!!!!!!!!!!!!!!!!

Thanks,
Erik
-- 
Be water, my friend.
                        -- Bruce Lee

Message #18 received at 19243-done <at> debbugs.gnu.org (full text, mbox):

From: Eric Blake <eblake <at> redhat.com>
To: Erik Auerswald <auerswal <at> unix-ag.uni-kl.de>, 19243-done <at> debbugs.gnu.org,
 "Chema F. Ledesma" <hecam33 <at> gmail.com>
Subject: Re: bug#19243: echo comand bug
Date: Tue, 02 Dec 2014 06:22:13 -0700

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On 12/02/2014 02:28 AM, Erik Auerswald wrote:
> Hi,
> 
> On Mon, Dec 01, 2014 at 11:12:51AM -0700, Eric Blake wrote:
>> On 12/01/2014 10:56 AM, Chema F. Ledesma wrote:
>>>
>>> If you execute echo "!!!!!!!!!!!!!!!!!!!!!!!!" it does something strange
>>> repeating the last command before echo comand.
>>
>> Thanks for the report.  However, this is not a bug in 'echo', but a
>> feature of your shell.
> 
> And because of this you can use single quotes instead of double quotes to
> print those exclamation marks:
> 
> $ echo '!!!!!!!!!!!!!!!!!!!!!!!!'
> !!!!!!!!!!!!!!!!!!!!!!!!

Or turn off history expansion:

$ set +o history
$ echo "!!!!"
!!!!

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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