Found a great post over at good coders code, great reuse. This one deals with performing operations on sets using only unix (bash) command line operations on files of text.

* Set Membership. Test if an element belongs to a set.
* Set Equality. Test if two sets contain the same elements.
* Set Cardinality. Return the number of elements in the set.
* Subset Test. Test if a given set is a subset of another set.
* Set Union. Find union of two sets.
* Set Intersection. Find intersection of two sets.
* Set Complement. Given two sets A and B, find all elements in A that are not in B.
* Set Symmetric Difference. Find symmetric difference of two sets.
* Power Set. Generate all subsets of a set.
* Set Cartesian Product. Find A x B.
* Disjoint Set Test. Test if two sets are disjoint.
* Empty Set Test. Test if a given set is empty.
* Minimum. Find the smallest element of a set.
* Maximum. Find the largest element of a set.

It deals with such commands as sed, awk, tr, sort, comm, grep and wc. This is a good post for anyone dealing with data via command line linux.

Full article here.

It is possible to install Active Directory authentication in Ubuntu 8.04 and later. The Likewise Open packages accomplish this task, and it is actually pretty easy.

Just a note – when installing Ubuntu, do not add a user named “administrator” as I did. This makes it impossible to join the Ubuntu workstation to the domain using the “administrator” active directory user – but you can use a different Domain Administrator username and password.

The steps to follow:

1. sudo apt-get install likewise-open
2. sudo domainjoin-cli join fdqn.yourdomainserver Administrator
3. sudo update-rc.d likewise-open defaults
4. sudo /etc/init.d/likewise-open start

As a side note – you should also consider adding the following code to make it so that users do not have to login with DOMAIN\username on the ubuntu login screen. You can do this by changing /etc/samba/lwiauthd.conf and adding this line:

winbind use default domain = yes

Also, another helpful tidbit of information is getting your Ubuntu machine to resolve netbios domain names. You can do this by adding missing entries to the following lines in /etc/nsswitch.conf:

passwd: compat winbind lwidentity
group: compat winbind lwidentity
shadow: compat winbind
hosts: files dns winbind

If you receive an “ERROR” message when you try to login to Ubuntu, it could be because the likewise-open service isn’t running. Running “update-rc.d likewise-open defaults” should start it but troubleshoot this script to make sure it is indeed running on boot.

For More Information:
Official Likewise-open page on Ubuntu

If you receive this error while opening Excel or other Microsoft Office programs, it is usually caused by an Adobe PDF addon that is having problems. According to Microsoft, this can happen if:

1. The Microsoft Office Startup folder or the Microsoft Excel Startup folder contains either or both of the following Adobe Acrobat PDFMaker add-in template files:
Pdfmaker.dot
Pdfmaker.xla
AND
2. Norton AntiVirus software is installed.

To fix it, delete the files from the startup Office folder. There are a few locations it might be, in my case it was in C:\Program Files\Microsoft Office\Office12\XLSTART. See this Microsoft KB Article on fixing the error.