$file =
'0.000000e+000 1.502947e+000
1.162272e-012 1.508957e+001
2.324544e-012 1.508948e+000';

my $regex = {
 'first'  => qr{^(\S+)},  # anything non-blank from the beginning '^'
 'second' => qr{\s+(\S*)} # anything non-blank after the fist blank '\
+s+'
};

for(split '\n', $file){
 /$regex->{first}$regex->{second}/o # 'o' compiles the regex
 and # and upon success we take the first column and/or the second one
 print "Key: $1 and Value: $2\n";
 # So hash structure can have $hash{$1} = $2
}
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