Perl program to Remove segment in a file

Question

I have a file which contains the following

blah
blah blah
Zebra
Blah blah blah
Blah
Bleh
Dog
Blag 
Noblah
Someblah

I want to remove the line segment from Zebra and Dog. Remove only those where Zebra occurs first and Dog occurs later.

How to do this in a perl script ?

Answer 1

Like How do I remove a specific area of element from an array, this is a use case for the flip-flop operator.

perl -ne 'print unless /Zebra/ .. /Dog/' < input-file

Answer 2

perl -ne'$r ||= /^Zebra$/; print if !$r; $r &&= !/^Dog$/;'

or

perl -ne'print if !( /^Zebra$/ .. /^Dog$/ );'

These assume every Zebra and Dogs are paired, and that they can't be nested.

See Specifying file to process to Perl one-liner.