Replace last occurrence of a string

Monday, June 17, 2013 perl 0 Comments

How do you replace  instances of a string only in the line where they last occured.
for example if you have a file like below:

a
b
c
a
d

The output should look like below:

a
b
c
x
d

Below is the perl command that will perform the same:

perl -e '@a=reverse<>;
         END{
            for(@a){
             if(/a/){s/a/c/;last}
             }
            print reverse @a}' your_file