Thursday, September 30, 2010

The Khan Academy is Teaching the Online World

Here is a great learning site to help brush up on your algebra, geometry, trigonometry, and calculus skills. You can also find courses for economics, finance, history and science. This growing site is called the Khan Academy. The instructor, Salman Khan, is helping current students and former students gain or regain their footing with these topics. He basically provides a 10 minute block of instruction (due to youtube’s time limit) on a given topic, which is short enough to keep your attention span. His site offers over 1800 different courses.

Salman gave up a successful career in finance to share his vast knowledge with the world for FREE. From what I can see, he’s a terrific math teacher.

The Khan Academy is a not-for-profit 501(c)(3) with the mission of providing a world-class education to anyone, anywhere.

Check out the Khan Academy and its amazing story.

And by the way, the Academy was recently selected by Google's project 10^100

Friday, July 02, 2010

Use Redirect Symbol to Zero File

I have mentioned this topic in an earlier post - zero'ing logfiles with cat /dev/null > logfile. But there is another easy way to zero a logfile in Bourne or Korn shell. It probably works in Bash and Zsh, too. I have to check. Here is an example below.

Note: I used the gts to represent the "greater than" or redirect symbol because blogger complained about using that particular character. Update: themadengineer reminded me on the use of "greater than" html syntax. Thanks.

Bourne Shell at the command prompt
# > mylogfile


Korn Shell at the command prompt
# > mylogfile

Monday, June 28, 2010

Run the Windows Explorer GUI

Here are a few easy ways to invoke the Windows Explorer GUI, which displays certain parts of the directory/folder tree depending on given syntax. I also threw in a few other miscellaneous items.

1. Select Run
Then type "."
This action will invoke the C:\Documents and Settings\mysysad

2. Select Run
Then type ".."
This action will invoke a window that displays C:\Documents and Settings

3. Select Run
Then type "..."
This action will invoke a window that displays My Computer

Other misc Run exercises

Select Run
Type "explorer" - same as Type "My Documents"
Type "explorer c:"
Type "explorer desktop"
Type "explorer ."
Type "explorer .."

Select Run
Type "control panel"

Select Run
Type "recent"

Select Run
Type "calc"

Select Run
Type "notepad"

Select Run
Type "wordpad"

Select Run
Type "ping MySysAdDOTCOM"

Select Run
Type "c:" or "d:" or "a:"

Select Run
Type "freecell"
Type "sol"
Type "mshearts"
Type "spider"
Type "winmine"

Select Run
Type "mspaint"

Select Run
Type "nslookup"

Select Run
Type "cmd"

Thursday, May 06, 2010

Retrieve Information on LDAP User

Here are a couple easy methods to get information from ldap for a particular user. Friend and I were talking about it yesterday because we had a typo in someone's login directory string (missing a character). He showed me a fancy one-liner but all I needed was a username, login directory, and its corresponding UID.

# ldaplist -l password username

# getent passwd username

# logins -x | grep username

The getent command is also handy to retrieve host and group information. It consults what databases are listed in the /etc/nsswitch.conf file.

# getent hosts hostname
# getent group 100

Tuesday, April 27, 2010

$HOME/.TTauthority not writable, auth entry not added

After being absent from the work site for an extended period, I had a little problem with the dt session. I was being blocked a dt session (automatically logged me out--tried 3x). I observed Tooltalk/dt session errors on the screen.

But I also observed others logging into the same box without incident. Intuitively, I suspected something was wrong with my environment, so I logged in via a remote terminal. Once in the box, I reviewed the /var/adm/messages file and noticed /usr/dt/bin/ttsession errors were associated with my username. The messages file also contained this telling message - $HOME/.TTauthority not writable, auth entry not added.

Hmmm…ownership was not mine. I changed the ownership to yours truly and everything worked like a champ.

Wednesday, March 03, 2010

Microsoft Security Advisory --- F1 Key on Web

A friend of mine from Japan emailed me this interesting article and thought I would share it.

Microsoft has issued a security advisory warning users NOT to press the F1 key when prompted by a website. This vulnerability could allow a hacker to hijack a computer. This vulnerability affects all versions of Internet Explorer on computers running Windows 2000 and Windows XP operating systems. More information can be found at

DO NOT press the F1 key if prompted by a website. Doing so could allow a hacker to hijack your computer!

Saturday, February 27, 2010

Import and Enable the NFS Service

Last week we had a little issue with mounting directories from a new Solaris 10 server. It was noted the nfs service was not running on it. We had to import and then enable the service. After that, we were able to mount the required directories from the server.

# svcs -a | grep nfs
# cd /var/svc/manifest/network
# svccfg -v import nfs/server.xml
# svcadm enable nfs/server


# svccfg -v import /var/svc/manifest/network/nfs/server.xml
# svcadm enable nfs/server

If you want to disable and delete a service, see below.

# svcadm disable network/nfs/server
# svccfg delete network/nfs/server