DNS Text Label List Splitter

Split ASCII DNS presentation text into explicit label octets with \DDD or escaped-character spelling; no Unicode IDNA conversion and root/absolute status is explicit.

Description

Split ASCII DNS presentation text into explicit label octets with \DDD or escaped-character spelling; no Unicode IDNA conversion and root/absolute status is explicit.

Dots separate DNS labels in presentation text unless escaped. This parser exposes octets and distinguishes an explicit absolute name from a relative spelling.

When to use this tool

Split ASCII DNS presentation text into explicit label octets with \DDD or escaped-character spelling; no Unicode IDNA conversion and root/absolute status is explicit.

Prepare the supplied name fields for this operation.
Compare the complete example with the representation used by your own input before carrying the result into another step.

How to use the tool and how it works

Enter name. Use the exact text syntax, units and index conventions explained below.
Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
Read result.labels, result.absolute. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.

Scan name, splitting on unescaped dots. Decode a backslash followed by three digits as one decimal octet, or another escaped character as its byte. A final dot sets absolute; a single dot is the empty-label root. Validate nonempty labels and wire budgets.^[1]

Input field	Meaning and representation	Accepted input
name	name.	Text; at most 8,192 UTF-16 code units, subject to the grammar above

Output field	Interpretation
result	Object containing the named outputs below.
result.labels	The labels list in the ordering and representation described above.
result.absolute	Flag for absolute under the exact condition described above.

json

{
  "input": {
    "name": "a\\046b.example."
  },
  "output": {
    "result": {
      "labels": [
        [
          97,
          46,
          98
        ],
        [
          101,
          120,
          97,
          109,
          112,
          108,
          101
        ]
      ],
      "absolute": true
    }
  }
}

Limitations and assumptions

Unescaped text is restricted to printable ASCII; escaped characters must fit a byte. No IDNA conversion, resolution or zone inference occurs.
All declared input fields are required and unexpected top-level fields are rejected. Numbers must be finite; lists are limited to 128 entries and ordinary text fields to 8,192 UTF-16 code units, with tighter limits where stated.
JSON text inputs must parse within bounded nesting and size limits. Numeric outputs outside the safe finite range are rejected; large exact integer results use decimal strings. Indexes and half-open spans are zero-based unless a rank is explicitly described as one-based.

Alternative or Complementary methods

Use a packet-aware DNS parser or resolver when the task requires compression-chain validation, live records or complete resource-record semantics. Keep byte labels, presentation text and network packets distinct.

References

Tool behavior and example: DNS Text Label List Splitter — tool.io

Similar or alternative tools

DNS Text Label List Joiner
Join explicit DNS label octets into ASCII presentation text using decimal escapes for dots, backslashes and nonprintable octets; root is a single dot.
DNS Label ASCII Case Normalizer
Canonicalize DNS ASCII uppercase octets only, leaving non-ASCII bytes unchanged; does not apply Unicode lowercase or IDNA mappings.