If you use trace rather than printf to capture data, the dtrace command formats the results by using a default output format. If the data is 1, 2, 4, or 8 bytes in size, the result is formatted as a decimal integer value. If the data is any other size, and is a sequence of printable characters if interpreted as a sequence of bytes, it is printed as an ASCII string. If the data is any other size, and is not a sequence of printable characters, it is printed as a series of byte values that is formatted as hexadecimal integers.