 double.
<B>:String</B> means the C function returns a pointer to a string,
and EusLisp should add a long-word header to the  string to accomodate it
as a EusLisp string.
The length of the string is found by <EM>strlen</EM>.
Note that the writing a header just before the string may cause
a disastrous result.
On the other hand, <B>(:string n)</B> is safer but slower because
a EusLisp string of length <B>n</B> is newly created and the contents of
C string is copied there.
<TT>(:string 4)</TT> should be used f