Question

I want to find a line in a txt file and then insert string 3 lines above the found line

Input:

aaa
bbb
ccc
ddd
eee
fff

I want to look for “eee” and then print “WWW” 3 lines above it. Output:

aaa
WWW
bbb
ccc
ddd
eee
fff

I’m using awk and can only print “WWW” 1 line above “eee”, and not 3:

awk '/eee/{print "WWW"} 4' file.txt

any ideas?

Answer 1

One way:

awk '{a[NR]=$0;}/eee/{a[NR-3]="www\n" a[NR-3];}END{for(i=1;i<=NR;i++)print a[i];}' file