How to search and replace on multiple lines in multiple methods using perl?

 

Method1:

perl -i -pe 's/START.*STOP/replace_string/g' file_to_change

Method2:
 

perl -i -pe 'BEGIN{undef $/;} s/START.*STOP/replace_string/smg' file_to_change

Method3:

 

perl -0pe 's/search/replace/gms' file

Method4:

 

local $/ = undef;

   open INFILE, $full_file_path or die "Could not open file. $!";

   $string =  <INFILE>;

   close INFILE;