#!/usr/bin/perl

use strict;
use warnings;

my $bool = 0;

while( my $line = <DATA> ){
  if( $line =~ /^\/begin blubber/ ){
     $bool = 1;
  }

  print $line unless $bool;

  if( $line =~ /^\/end blubber/ ){
     $bool = 0;
  }
}

__DATA__
Text
am
Anfang
/begin blubber skdjflkdsjf
sdlkfjdsk
lksjflksdj
aajjllja
/end blubber
Text
am
Ende