Subject: Re: bug#13144: "comm" bug or strange behaviour

From: Bob Proulx <[email-masked]>
Date: Tue, 11 Dec 2012 21:53:57 -0700

Matteo Zambelli wrote:
> Hi, i was trying to find common lines between the two attached
> files(both created with "dpkg --get-selections > filename.txt") with
> this command:
> 
> comm -12 squeeze-xfce-installed_packages.txt squeeze-xfce-installed_packages.txt > result.txt
> 
> then i noticed that the line:
> 
> libcdio10                                       install
> 
> that is regularly present in both files, doesn't appear in the
> result(as well as few other lines).

Thank you for the report.  Also thank you for including the data sets
needed to reproduce the activity.  That's great.

Unfortunately I cannot reproduce your result.

  $ comm -12 squeeze-xfce-installed_packages.txt squeeze-xfce-installed_packages.txt | grep libcdio10
  libcdio10					install

And so there it is in the output??

> I have tried with option "--nocheck-order" and such, but those common
> lines are still missing in the output file.

Try 'sort -c' to check the sort ordering of both files.  (Looked okay
to me but it is locale dependent.)

What is your 'locale' setting?  (Affects sort order.)

  $ locale

In this case it shouldn't matter but what version of comm are you
using?  I know you reported your kernel version but that isn't really
associated.  (Think Squeeze with Backports.)

  $ comm --version

Verify that the 'comm' binary that you are running is the expected
one:

  $ type comm
  comm is hashed (/usr/bin/comm)

Bob