HTTP Token Character Audit

Audit HTTP token characters and zero-based Unicode scalar positions; an empty token is invalid even with no offending character.

Description

Audit HTTP token characters and zero-based Unicode scalar positions; an empty token is invalid even with no offending character.

An HTTP token has a restricted ASCII character vocabulary and must be nonempty. A diagnostic can identify disallowed characters.

When to use this tool

Audit HTTP token characters and zero-based Unicode scalar positions; an empty token is invalid even with no offending character.

Prepare the supplied value 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 value. 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.valid, result.invalidOffsets. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.

Test the full value against the HTTP token character expression. Separately iterate its Unicode code points and report positions whose individual character fails that vocabulary.^[1]

Input field	Meaning and representation	Accepted input
value	value.	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.valid	Flag for valid under the exact condition described above.
result.invalidOffsets	The invalid offsets list in the ordering and representation described above.

json

{
  "input": {
    "value": "bad name"
  },
  "output": {
    "result": {
      "valid": false,
      "invalidOffsets": [
        3
      ]
    }
  }
}

Limitations and assumptions

invalidOffsets are code-point iteration indexes, not UTF-16 byte or code-unit offsets. Empty input is invalid but has no offending character positions; no full header grammar is checked.
Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
String lists have at most 128 entries of at most 128 code units; matrices have at most 128 rows and columns. Larger numeric lists and parsed JSON have separate bounded budgets. Nonfinite results and excessively large serialized outputs are rejected.
Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.

Alternative or Complementary methods

Use a complete protocol or URL parser when interpreting a whole message or address. Preserve raw spelling when required and distinguish HTTP token grammar, URL path normalization and form-style query decoding.

References

Tool behavior and example: HTTP Token Character Audit — tool.io

Similar or alternative tools

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