GNU bug report logs - #30794
Cannot produce backslash through hexadecimal - sed (GNU sed) 4.2.2

Previous Next

Full log

View this message in rfc822 format

From: help-debbugs <at> gnu.org (GNU bug Tracking System)
To: Jim Meyering <jim <at> meyering.net>
Cc: tracker <at> debbugs.gnu.org
Subject: bug#30794: closed (Cannot produce backslash through hexadecimal -
 sed (GNU sed) 4.2.2)
Date: Thu, 15 Mar 2018 00:20:02 +0000

[Message part 1 (text/plain, inline)]

Your message dated Wed, 14 Mar 2018 17:18:43 -0700
with message-id <CA+8g5KH6Dm_-QsARyLwdP6UkEeOt9Z_H5JQq_YFBUxk2A-gDsA <at> mail.gmail.com>
and subject line Re: bug#30794: Cannot produce backslash through hexadecimal - sed (GNU sed) 4.2.2
has caused the debbugs.gnu.org bug report #30794,
regarding Cannot produce backslash through hexadecimal - sed (GNU sed) 4.2.2
to be marked as done.

(If you believe you have received this mail in error, please contact
help-debbugs <at> gnu.org.)


-- 
30794: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=30794
GNU Bug Tracking System
Contact help-debbugs <at> gnu.org with problems

[Message part 2 (message/rfc822, inline)]

From: 0xddaa <0xddaa <at> gmail.com>
To: bug-sed <at> gnu.org
Subject: Cannot produce backslash through hexadecimal - sed (GNU sed) 4.2.2
Date: Tue, 13 Mar 2018 18:02:05 +0800

[Message part 3 (text/plain, inline)]

Hi,

I use sed to modify the field of size in file header for some binaries, and
I found it will failed when the file size included *\x5c* (backslash) after
converted into hexadecimal.

There is the Proof-of-Concept:

# echo z | sed 's/z/\x5c/' # \x5c == '\'
\ # success
# echo z | sed 's/z/\x5c\x61/'
a # backslash is gone

According the manual, *\xxx* should produce an ascii character. sed should
not treat *\x5c* as an escape symbol.

I also try the replacement with '&' and it's work fine:

# echo z | sed 's/z/\x26\x61/' # \x26 == '&'
&a // replace to &
# echo z | sed 's/z/&\x61/'
za  // execute & feature

I try to fix the problem and I hope it will be useful. Sorry for my bad
English.
https://github.com/0xddaa/sed/commit/723fa224c771ecd16913aea8117aa917877bbd38

Sincerely,
ddaa

[Message part 4 (text/html, inline)]

[Message part 5 (message/rfc822, inline)]

From: Jim Meyering <jim <at> meyering.net>
To: Assaf Gordon <assafgordon <at> gmail.com>
Cc: 0xddaa <0xddaa <at> gmail.com>, 30794-done <at> debbugs.gnu.org
Subject: Re: bug#30794: Cannot produce backslash through hexadecimal - sed
 (GNU sed) 4.2.2
Date: Wed, 14 Mar 2018 17:18:43 -0700

On Wed, Mar 14, 2018 at 3:43 PM, Assaf Gordon <assafgordon <at> gmail.com> wrote:
> Replying to myself:
>
> On Wed, Mar 14, 2018 at 04:34:18PM -0600, Assaf Gordon wrote:
>> > [...]
>> > sed-1.18 : x5c1
>> > sed-2.05 : x5c1
>> > sed-3.01 : x5c1
>> > sed-3.02 : x5c1
>> > [...]
>
> I checked the NEWS file,
> and found that backslash sequences (e.g. \n \t \xNN \dNNN \oNNN)
> were added in version 3.02.80 (which I don't think is common and
> we don't have the source code).
>
> I changed the NEWS accordingly (attached updated patch).
>
> OK to push?

Sure. Re the "bug present since..." issue, my intent was to convey
that \x5c never worked the way we now consider correct.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.