Groovy equivalent of Perl/ PHP pack("N", int) function.

packN_groovy

// Groovy equivalent of:
//      PHP:  pack("N", 123)    and unpack("N", str)
//      Perl: pack("N", 123)    and unpack("N", str)

static String packN(int value) {
	def bytes = ByteBuffer.allocate(4).putInt(value).array()
	bytes = toPositiveByteArray(bytes)
	(bytes as char[]).toString()
}

static int unpackN(String value) {
	def bytes = (value.chars as int[]) as byte[]
	ByteBuffer buf = ByteBuffer.allocate(4)
	buf.order(ByteOrder.BIG_ENDIAN)
	buf.put(bytes)
	buf.flip()
	buf.getInt()
}

// converts a byte[] like [0,0,19,-2] to [0,0,19,254]
static def toPositiveByteArray(bytes) {
	bytes.collect {
		it < 0 ? 256 + it : it
	}
}