how to delete lines using SED

[unixxxx]

I have question about sed. If I have a file and I want to delete all lines in the file except the lines that start with the word "HELLO". How should I make a script using sed command? [sig][/sig]

 

[unixxxx]

never mind...i know how to do it [sig][/sig]

 

[Heyman]

Well please post your answer. Some of us would like to know as well. [sig][/sig]

 

[mgdaviso]

Why sed? Why not use grep to extract all the lines with HELLO in it?

cat filename.txt | grep "HELLO" > newfile.txt Mike davison
mike.davison@avon.com

 

[rbobbitt]

Or, without the pipe:

# grep 'HELLO' filename.txt > newfile.txt

Russ
bobbitts@hotmail.com

http://home.earthlink.net/~bobbitts

 

[MikeLacey]

errmmmm --- *starting* with 'HELLO' guys...... LOL

grep '^HELLO' filename > outputfile
Mike
michael.j.lacey@ntlworld.com

 

[ElgisRamon]

That will do it... it's Mike fighting the Unix battle again!

 

[MikeLacey]

who me? <smile>
Mike
michael.j.lacey@ntlworld.com