#!/usr/bin/perl -w

use strict;
use warnings;
open(DAT,"datei.txt") || die $!;
local $/;
my $line = <DAT>;
print $1 if $line =~ /"(.*?)"/s;
close(DAT);

datei.txt:

my $var = "BrownWolf";
my $ujd = "
a
b
c
d
";

Ausgabe:

BrownWolf