UNIX for Dummies Questions & Answers

Hi,
I have the file telx2 where the 20 first lines are like this
ROOT 2310-111111
and the rest like
V13
ASVESTAS

I want with the use of sed in the 20 first lines to use the first field (it is a username) to create an e-mail address like ROOT@it.teithe.gr and replace the line so the result will look like this:

ROOT ROOT@it.teithe.gr 2310-111111

I tried this
sed 's/\([A-Z]*\) \([0-9]\{4\}-[0-9]\{6\}\)/\1 \1@it.teithe.gr \2/20' telx2 < telx2

which I think it should be working but no luck.

Please help

sed -e '1,20s/^\([^ ][^ ]*\) *\(.*\)$/\1 \1@it.teithe.gr \2/' telx2

Code:

sed '1,20s/^\([^ ]*\)\(.*\)/\1\@somewhere.com\2/p' telx2 > newfile

Thanks for the fast reply but unfortunately it's not working.

and reborg's?

any of these should work

Code:

my original suggestion 
sed '1,20s/^\([^ ]*\)\(.*\)/\1\@it.teithe.gr\2/p' telx2 > newfile

or two based on vgersh99's original
sed -e '1,20s/^\([^ ][^ ]*\)[ ]*\(.*\)$/\1 \1@it.teithe.gr \2/' telx2

sed -e '1,20s/^\([^ ][^ ]*\)\(.*\)$/\1 \1@it.teithe.gr\2/' telx2

when I replied before I didn't see reborg's reply. The code above is working but i changed it a bit to be like I wanted.

Code:

sed '1,20s/^\([^ ]*\)\(.*\)/\1 \1\@it.teithe.gr\2/p' telx2 > newfile

Thanks a lot