use strict;
use warnings;

use IO::Handle;

my @files   = qw(t1.txt t2.txt t3.txt);
my @handles = ();

for ( @files )
{
    push @handles, new IO::Handle;
    open $handles[-1], "<", $_ or die "cannot open $_!\n";
}

while (1)
{
    my @data;

    for my $handle ( @handles )
    {
        my $line = <$handle>;
        exit unless defined $line;

        chomp $line;

        $line =~ /= ([^=]+)/;
        push @data, $1;
    }

    print "@data\n";
}