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[Zakhar <1499473@xxxxxxxxxxxxxxxxxx>]

Public bug reported:

VERSION AND CONTEXT
===================

$ uname -a; lsb_release -a; dash --version; dpkg -s dash
Linux alain-Desktop 3.13.0-63-generic #103-Ubuntu SMP Fri Aug 14 21:42:59 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 14.04.3 LTS
Release:	14.04
Codename:	trusty

Package: dash
Essential: yes
Status: install ok installed
Priority: required
Section: shells
Installed-Size: 228
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@xxxxxxxxxxxxxxxx>
Architecture: amd64
Version: 0.5.7-4ubuntu1
Depends: debianutils (>= 2.15), dpkg (>= 1.15.0)
Pre-Depends: libc6 (>= 2.14)
Description: POSIX-compliant shell
 The Debian Almquist Shell (dash) is a POSIX-compliant shell derived
 from ash.
 .
 Since it executes scripts faster than bash, and has fewer library
 dependencies (making it more robust against software or hardware
 failures), it is used as the default system shell on Debian systems.
Homepage: http://gondor.apana.org.au/~herbert/dash/
Original-Maintainer: Gerrit Pape <pape@xxxxxxxxxxx>


BUG DESCRIPTION AND HOW TO REPRODUCE
====================================
Pretty well all is in the title!

Try this in a terminal:

$ bash -c 'printf "\x41\n"'; dash -c 'printf "\x41\n"'; $(which printf) '\x41\n'
A
\x41
A

In case you suspect that comes from expansion in the terminal, you can
do the same under dash (type dash in the terminal and do the same line).
The result is identical.

Same thing if you have a script:

#! /bin/dash

printf '\x41\n'
printf "\x41\n"  # We do both quotes and double quotes in case there is an escaping issue!

This script will display:
\x41
\x41


WHAT IS EXPECTED:
================
Of course what is expected is that dash would display, same as bash and GNU printf:
A

That is what is described in all printf's documentations I could ever
read, starting from the ancestor:

#include <stdio.h>

int main(){
   printf("\x41\n");
}

Name this file /tmp/test.c, compile it with gcc /tmp/test.c -o /tmp/test
Then run /tmp/test
You will obviously get:
A


SUMMARY:
========
Testing various printfs with the string: "\x41\n"

Produces the expected output (capital letter A followed by line feed) with:
- the C printf
- the bash builtin
- the GNU printf (in /usr/bin)

Produces an un-escaped output with dash!

I am still searching for dash documentation of the builtin printf, but I
seriously doubt such an output for printing '\x41' is even POSIX
compliant.


INTERSTING NOTE:
===============
We could suspect there would be the same issue when converting numbers from octal... but no, all is fine with octal!

$ bash -c 'printf "\101\n"'; dash -c 'printf "\101\n"'; $(which printf) '\101\n'
A
A
A

In octal, be it bash, dash or the GNU printf all outputs are identical.

In any case someone might consider "it is not a bug, it is a feature" to
NOT honour escaping of hexadecimal and honour the octal escaping we can
say at least that this "feature" is a lack of consistency in converting
numbers to chars with dash!


INTERESTING NOTE2:
=================
I read from the description of dash on the launchpad:  (...) 'dash' which is the Debian Almquist Shell (dash) is a POSIX-compliant shell derived from ash.

Well, I did the same test on my (not Ubuntu-related) Synology that is
precisely running ash embedded in busybox (not bash, not dash) and doing

printf '\x41\n'

Produces the expected output: A + LF

[Exact version of this 'ash': BusyBox v1.16.1 (2014-02-11 20:12:01 CST)
built-in shell (ash) ]

So there might have been some distortion in the derivation from ash!

** Affects: dash (Ubuntu)
     Importance: Undecided
         Status: New

-- 
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Touch seeded packages, which is subscribed to dash in Ubuntu.
https://bugs.launchpad.net/bugs/1499473

Title:
  dash printf builtin does not honor \xNN to print hexadecimal

Status in dash package in Ubuntu:
  New

Bug description:
  VERSION AND CONTEXT
  ===================

  $ uname -a; lsb_release -a; dash --version; dpkg -s dash
  Linux alain-Desktop 3.13.0-63-generic #103-Ubuntu SMP Fri Aug 14 21:42:59 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

  No LSB modules are available.
  Distributor ID:	Ubuntu
  Description:	Ubuntu 14.04.3 LTS
  Release:	14.04
  Codename:	trusty

  Package: dash
  Essential: yes
  Status: install ok installed
  Priority: required
  Section: shells
  Installed-Size: 228
  Maintainer: Ubuntu Developers <ubuntu-devel-discuss@xxxxxxxxxxxxxxxx>
  Architecture: amd64
  Version: 0.5.7-4ubuntu1
  Depends: debianutils (>= 2.15), dpkg (>= 1.15.0)
  Pre-Depends: libc6 (>= 2.14)
  Description: POSIX-compliant shell
   The Debian Almquist Shell (dash) is a POSIX-compliant shell derived
   from ash.
   .
   Since it executes scripts faster than bash, and has fewer library
   dependencies (making it more robust against software or hardware
   failures), it is used as the default system shell on Debian systems.
  Homepage: http://gondor.apana.org.au/~herbert/dash/
  Original-Maintainer: Gerrit Pape <pape@xxxxxxxxxxx>


  BUG DESCRIPTION AND HOW TO REPRODUCE
  ====================================
  Pretty well all is in the title!

  Try this in a terminal:

  $ bash -c 'printf "\x41\n"'; dash -c 'printf "\x41\n"'; $(which printf) '\x41\n'
  A
  \x41
  A

  In case you suspect that comes from expansion in the terminal, you can
  do the same under dash (type dash in the terminal and do the same
  line). The result is identical.

  Same thing if you have a script:

  #! /bin/dash

  printf '\x41\n'
  printf "\x41\n"  # We do both quotes and double quotes in case there is an escaping issue!

  This script will display:
  \x41
  \x41

  
  WHAT IS EXPECTED:
  ================
  Of course what is expected is that dash would display, same as bash and GNU printf:
  A

  That is what is described in all printf's documentations I could ever
  read, starting from the ancestor:

  #include <stdio.h>

  int main(){
     printf("\x41\n");
  }

  Name this file /tmp/test.c, compile it with gcc /tmp/test.c -o /tmp/test
  Then run /tmp/test
  You will obviously get:
  A

  
  SUMMARY:
  ========
  Testing various printfs with the string: "\x41\n"

  Produces the expected output (capital letter A followed by line feed) with:
  - the C printf
  - the bash builtin
  - the GNU printf (in /usr/bin)

  Produces an un-escaped output with dash!

  I am still searching for dash documentation of the builtin printf, but
  I seriously doubt such an output for printing '\x41' is even POSIX
  compliant.

  
  INTERSTING NOTE:
  ===============
  We could suspect there would be the same issue when converting numbers from octal... but no, all is fine with octal!

  $ bash -c 'printf "\101\n"'; dash -c 'printf "\101\n"'; $(which printf) '\101\n'
  A
  A
  A

  In octal, be it bash, dash or the GNU printf all outputs are
  identical.

  In any case someone might consider "it is not a bug, it is a feature"
  to NOT honour escaping of hexadecimal and honour the octal escaping we
  can say at least that this "feature" is a lack of consistency in
  converting numbers to chars with dash!

  
  INTERESTING NOTE2:
  =================
  I read from the description of dash on the launchpad:  (...) 'dash' which is the Debian Almquist Shell (dash) is a POSIX-compliant shell derived from ash.

  Well, I did the same test on my (not Ubuntu-related) Synology that is
  precisely running ash embedded in busybox (not bash, not dash) and
  doing

  printf '\x41\n'

  Produces the expected output: A + LF

  [Exact version of this 'ash': BusyBox v1.16.1 (2014-02-11 20:12:01
  CST) built-in shell (ash) ]

  So there might have been some distortion in the derivation from ash!

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