Shell Programming and Scripting

Hi All,

I want to write a script which first check the line counts of a file if its more than 500 it deletes rest except the last 500..

I tried sed but it looks sed counts line numbers from the head & not from tail.. May be I need a wc -l frist then apply if statement & pass on the line count to the sed statement..

Can you please suggest me a way to do..

I am using Solaris 10 box...

Maybe some like this works

Code:

awk '(s-NR)<500' s=$(cat file | wc -l) file

man tail

Yes, why make it complex when there are commands to do this.
Maybe I am in love with awk
tail -n 500

tail is not deleting.. various use of tail is just displaying..

Code:

awk '(s-NR)<500' s=$(cat file | wc -l) file

is returning

"awk: can't open 664"

664 is actually the line number..

cat t

Code:

one
two
three
four
five
six
seven
eight
nine
ten

Code:

tail -n 3 t
eight
nine
ten

Code:

awk '(s-NR)<3' s=$(cat t | wc -l) t
eight
nine
ten

My purpose is to delete the lines except the last few..

For viewing the certain last few I would have used smaller one:

Code:

tail -3 t