private String getMaskedInputString(byte[] bytes, byte[] mask) {
		StringBuilder builder = new StringBuilder();
		for (int i = 0; i < bytes.length; i++) {
			String s = String.format("%02x", bytes[i]);
			builder.append((mask[i] & 0xf0) == 0 ? "." : s.charAt(0));
			builder.append((mask[i] & 0x0f) == 0 ? "." : s.charAt(1));
			builder.append(" ");
		}

		return builder.toString().trim();
	}
Returns the value of the given hex digit character.
Ghidra/Features/Base/src/main/java/ghidra/features/base/memsearch/format/HexSearchFormat.java