if ($d1 =~ /^white*/)

This matches any string consisting of 'whit' at the beginning followed by zero or more 'e' characters. Probably not what you wanted.

perl -Mstrict -WE '
say "`$_` " . ( $_ =~ /^white*/ ? "match" : "no match" )
    for ("while", "whine", "white", "whitf", "whit ", "whit!", "whit")
+;
'
[download]

`while` no match
`whine` no match
`white` match
`whitf` match
`whit ` match
`whit!` match
`whit` match
[download]

Hope this helps!