Inserting lines in a file using Perl

Wednesday, May 14, 2014 perl 0 Comments

I have input file that look's like :

cellIdentity="42901"
cellIdentity="42902"
cellIdentity="42903"
cellIdentity="52904"

Numbers inside the quotes can be anything. The output needed is original line followed by the copy of same line except the last digit of the number should be a series of 5,6,7. So the output should look like below:

cellIdentity="42901"
cellIdentity="42905"
cellIdentity="42902"
cellIdentity="42906"
cellIdentity="42903"
cellIdentity="42907"
cellIdentity="52904"
cellIdentity="52905"

Below is the Perl command that I have written.

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