I suspect split would be your best choice-

# split
my ($key, $string1) = split /=/, $_, 2;
print "$key, $string1\n";
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Though there are other ways-

#re 1
/^TITLE=(.*)/;
my $string2 = $1 || '';
print "$string2\n";

#re 2
(my $string3 = $_) =~ s/TITLE=//;
print "$string3\n";

# substr
my $string4 = substr($_, 6);
print "$string4\n";
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Just as examples. Which method you choose will depend on what else is going on in your program and what the most general case of your expression is. If it is *always* TITLE="some string" I might use substr. If it was (for example) "some text in upper followed by an equals followed by some string ending in a numeric" *and* I had to ignore other lines that include "=" I might use an regular expression.

--
my $chainsaw = 'Perl';