HTTP Parameter Name Duplicate Audit

Audit case-insensitive HTTP parameter-name duplicates using the existing quote-aware parameter parser; accepts a parameter list, not a whole header.

Description

Audit case-insensitive HTTP parameter-name duplicates using the existing quote-aware parameter parser; accepts a parameter list, not a whole header.

HTTP parameter names compare without ASCII case distinctions, while quoted values may contain semicolons. Splitting must respect quoting.

When to use this tool

Audit case-insensitive HTTP parameter-name duplicates using the existing quote-aware parameter parser; accepts a parameter list, not a whole header.

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

Split parameterList on semicolons using the shared quoted-header parser. Require every part to be a valid name=value parameter, lowercase its name and return repeated names with all parameter indexes.^{[1, 2]}

Input field	Meaning and representation	Accepted input
parameterList	parameter list.	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.duplicates	The duplicates list in the ordering and representation described above.

json

{
  "input": {
    "parameterList": "charset=utf-8; CHARSET=ascii"
  },
  "output": {
    "result": {
      "duplicates": [
        {
          "name": "charset",
          "indexes": [
            0,
            1
          ]
        }
      ]
    }
  }
}

Limitations and assumptions

This input is the parameter list itself, without a media type prefix. No duplicate-value conflict resolution, extended-parameter decoding or full header validation is performed.
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

HTTP Content-Type and parameter parser — tool.io
Tool behavior and example: HTTP Parameter Name Duplicate Audit — tool.io

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