perl -MList::Util="all" -lne "next unless/.../;my(%r,$c);$r{$_}++for(/./g);print if all{++$c==$_}sort values %r" linux.words

# or minimum 10 char words only

perl -MList::Util="all" -lne "next unless/.{10,}/;my(%r,$c);$r{$_}++for(/./g);print if all{++$c==$_}sort values %r" linux.words