That split(/ /,$foo) and split m/ /,$foo are exactly the same.    I was pointing out the difference between split m/ /, $line and split(" ", $line)

$ perl -le'
use Data::Dumper;
$Data::Dumper::Useqq = 1;
my $foo = "  abc\t\tdef\r\rghi\n";
print Dumper $_ for split / /, $foo;
'
$VAR1 = "";

$VAR1 = "";

$VAR1 = "abc\t\tdef\r\rghi\n";

$ perl -le'
use Data::Dumper;
$Data::Dumper::Useqq = 1;
my $foo = "  abc\t\tdef\r\rghi\n";
print Dumper $_ for split " ", $foo;
'
$VAR1 = "abc";

$VAR1 = "def";

$VAR1 = "ghi";
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