Insert text at the beginning of every even number line

Shell Programming and Scripting
1

i am trying to
insert text at the beginning of every even number line
with awk

i can do it with odd number lines
with this command

awk 'NR%2{$0="some text "$0}1' file

how can i edit this command

thanks

2

Do you mean something like:

awk 'NR%2 == 1{$0="some text "$0}1' file
1 Like
3

thanks for reply

i changed the == 1 to 2==0
now it works many thanks great forum

awk 'NR%2==0{$0="some text "$0}1' file
4

Ouch. Yes. Sorry. I wasn't paying close enough attention.

I'm glad you got it to work.

1 Like
5

Or you may use negation in your original command as follows:

awk '!NR%2{$0="some text "$0}1' file
6

Not quite. In awk ! has higher precedence than % so that evaluates as (!NR)%2 . But:

awk '!(NR%2){$0="some text "$0}1' file

would work.