my @list_of_Num_Extraction = ('2,4:3,5', '3,7:1,19');

my ($l, $r, $t, $b);
foreach (@list_of_Num_Extraction) {
    if ($_ =~ /^(\d+),(\d+):(\d+),(\d+)$/) {
        if ($1 > $3) { $l = $3; $r = $1; }
        else { $l = $1; $r = $3; }
        if ($2 > $4) { $t = $4; $b = $2; }
        else { $t = $2; $b = $4; }
        print "$l,$t $l,$b $r,$t $r,$b\n";
    }
}
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