my $string = quotemeta @TAGS2;

##</code><code>##

$ perl -wE 'my @x = qw{$ % ^}; my $y = quotemeta @x; say $y'
3

##</code><code>##

$ perl -wE 'my @x = qw{$ % ^}; my @y = map { quotemeta } @x; say "@y"'
\$ \% \^

##</code><code>##

while ( my $text =~ m/ ( .{0,25} $string.{0,25} ) /gisx ) {

##</code><code>##

my $x = ...

##</code><code>##

$x =~ /.../

##</code><code>##

my $text = ...
...
while ($text =~ ...