Monday, June 15, 2009

Astonishing Read - Abraham Lincoln's letter to his son's teacher

Below poem was supposedly written by Abraham Lincoln to his son’s school headmaster. For generations, millions of parents across the globe have wished that this BIG ORDER from Lincoln was being taught in their child’s school.

He will have to learn, I know,
That all men are not just,
All men are not true,
But teach him also,
That for every scoundrel there is a hero,
For every selfish politician,
There is a dedicated leader!

Teach him that for every enemy there is a friend,
It will take time I know but teach him if you can,
That a dollar earned is of far more value than five found!

Teach him to learn to lose and also to enjoy winning
Steer him away from envy, if you can
And teach him the secret of quiet laughter
Let him learn early, that the bullies are the easiest to lick!

Teach him if you can the wonder of books
But also give him time to ponder over the eternal mystery of birds in the sky,
Bees in the sun and flowers on the green hillside
In school teach him it is far more honorable to fail than to cheat!

Teach him to have faith in his own ideas,
Even if everyone tells him they are wrong
Teach him to be gentle with gentle people
And tough with the tough!

Try to give my son the strength, not to follow the crowd
When everyone is getting into the bandwagon!

Teach him to listen to all men,
But teach him also to filter all he hears on a screen of truth,
And take away the good that comes through!

Teach him if you can how to laugh when he is sad
Teach him there is no shame in tears!

Teach him to scoff at cynics,
And to beware of too much sweetness!

Teach him to sell his brawn and brain to the highest of bidders,
But never to put a price tag on his heart and soul!

Teach him to close his ears to a howling mob
And to stand and fight if he thinks he is right!

Treat him gently, but do not cuddle him,
Because only the test of fire makes fine steel!

Let him have the courage to be impatient,
Let him have the patience to be brave!


Teach him always to have sublime faith in himself,
Because then he will always have sublime faith in mankind
This is big order but see what you can do
He is such a fine little fellow, my son!

Yours sincerely,
Abraham Lincoln


Thursday, June 4, 2009

Astonishing. years of unix administration and never stumbled across this goodie?

SS: The Saviour

The ss command is used to dump socket statistics. It allows showing information similar to netstat command. It can display more TCP and state information than other tools. It is a new, incredibly useful and faster (as compare to netstat) tool for tracking TCP connections and sockets. SS can provide information about:

  • All TCP sockets.
  • All UDP sockets.
  • All established ssh / ftp / http / https connections.
  • All local processes connected to X server.
  • All the tcp sockets in state FIN-WAIT-1 and much more.


Most Linux distributions are shipped with ss and many monitoring tools. Being familiar with this tool helps enhance your understand of what's going on in the system sockets and helps you find the possible causes of a performance problem.

Task: Display All TCP Sockets

# ss -t -a

Task: Display All UDP Sockets

# ss -u -a

Task: Display All Established SMTP Connections

# ss -o state established '( dport = :smtp or sport = :smtp )'

Task: Display All Established HTTP Connections

# ss -o state established '( dport = :http or sport = :http )'

Task: Find All Local Processes Connected To X Server

# ss -x src /tmp/.X11-unix/*

Task: List All The Tcp Sockets in State FIN-WAIT-1

List all the TCP sockets in state -FIN-WAIT-1 for our httpd to network 202.54.1/24 and look at their timers:
# ss -o state fin-wait-1 '( sport = :http or sport = :https )' dst 202.54.1/24


The source code can be obtained from:
http://devresources.linux-foundation.org/dev/iproute2/download/ and more this is included in CentOS5.2.