I need help with something. I was wondering if someone could help me. I am working with my linux system and I need to know what the following commands mean, meaning what will these commands do if they are executed successfully. I have typed out these commands but I dont understand what they mean can you please help me?

I do know a little bit I know that sed -n suppresses automatic printing of pattern space and I know that sed is a stream editor.

These Commands are:
sed -n ' /t2/p' ../passwd >passfile

sed '/^$/d' ../project3

sed -n' /^$/!p' ../project3

sed -n '/^..*$/p' ../bigfile

sed '/^\ *$/d' ../project3

Anyones help would be greatly appreciated.
Samantha

Welcome to regular expressions. The man page is your best place to start, though it is pretty terse, it will give a quick idea on the command its self.

http://www.regular-expressions.info/

is a very, very good jumping off point, I can't recommend it enough. By the way, the latter part of those commands (../filename) is a tad bizarre if you're running a lot of these, why not cd to where you need to be?

Homework!!!

The best way to find out what those commands do would be to run them!!!

What books or online resources are you using to learn SED? Here is my favorite:
http://www.grymoire.com/Unix/