c:\@Work\Perl>perl -wMstrict -e
"print 'enter a string: ';
 my $string = <STDIN>;
 chomp $string;
 print qq{'$string' \n};
"
enter a string: )\n(
')\n('

##</code><code>##

c:\@Work\Perl>perl -wMstrict -le
"printf 'enter search regex: ';
 my $search = <STDIN>;
 chomp $search;
 ;;
 printf 'enter replacement string: ';
 my $replace = <STDIN>;
 chomp $replace;
 ;;
 print qq{doing s/$search/$replace/};
 ;;
 my $s = qq{as\ngh\njk};
 printf qq{%*s: '$s' \n}, 7, 'initial';
 ;;
 my @regex = (
   { lh => $search, rh => $replace, },
   );
 ;;
 for my $hr_s (@regex) {
   $s =~ s[ (?-x)$hr_s->{lh}]{ qq{qq{$hr_s->{rh}}} }xmsgee;
   }
 ;;
 printf qq{%*s: '$s' \n}, 7, 'final';
"
enter search regex: \n
enter replacement string: __\n__
doing s/\n/__\n__/
initial: 'as
gh
jk'
  final: 'as__
__gh__
__jk'