Insert lines in file

Question

I have input file that look's like :

cellIdentity="42901"
cellIdentity="42902"
cellIdentity="42903"

number's inside the string are diferent from file to file. What I want now is to create ouput file that look's like

cellIdentity="42901"
cellIdentity="42905"
cellIdentity="42902"
cellIdentity="42906"
cellIdentity="42903"
cellIdentity="42907"

So basicly I need to insert 3 new lines which will have the same values as from input file, only the last digit will be all the time 5, 6 , 7.

I tried with awk, and I think I'm on good way, but still missing something, so please help. Thanks

awk 'BEGIN{split("5 6 7",a," ")}NR%2==0{t=$0;sub(/.$/,a[++i],$2);$0=t RS $0}1' FS=\" OFS=\" /tmp/MC/Cell_F1 > /tmp/MC/Cell_F2

Answer 1

Yes, you are on a good way. The problem is that you perform the substitution on even lines in the input:

NR%2==0

Removing the check should fix the issue:

awk 'BEGIN{split("5 6 7",a," ")}{t=$0;sub(/.$/,a[++i],$2);$0=t RS $0}1' FS=\" OFS=\" /tmp/MC/Cell_F1 > /tmp/MC/Cell_F2

Answer 2

Based on your awk

awk 'BEGIN {split("5 6 7",a," ")} {print $0"\n" substr($0,1,18) a[++i] "\""}' file
cellIdentity="42901"
cellIdentity="42905"
cellIdentity="42902"
cellIdentity="42906"
cellIdentity="42903"
cellIdentity="42907"

I take some part of the original string and add numbers to it.
If you have other number, larger number, you may need to change it some.

Answer 3

Since you already have some awk answers. How about something in perl?

perl -pe 'BEGIN{$n=4}
          $n++>7?$n=5:$n;
          $a=$_;print $a;
          s/(\d).$/$n."\""/ge' your_file