has_key?

static VALUE
fgdbm_has_key(VALUE obj, VALUE keystr)
{
    datum key;
    struct dbmdata *dbmp;
    GDBM_FILE dbm;
    long len;

    StringValue(keystr);
    len = RSTRING_LENINT(keystr);
    if (TOO_LONG(len)) return Qfalse;
    key.dptr = RSTRING_PTR(keystr);
    key.dsize = (int)len;

    GetDBM2(obj, dbmp, dbm);
    if (gdbm_exists(dbm, key))
        return Qtrue;
    return Qfalse;
}