Description
Return octet = 160+utf8Bytes, combining the fixstr tag with its five-bit byte length.
MessagePack uses compact tag families for small integers, short strings and small containers. A header can carry a count directly, but that count must agree with the following encoded items or UTF-8 bytes.
Return octet = 160+utf8Bytes, combining the fixstr tag with its five-bit byte length.
When to use this tool
Use Msgpack Fixstr Length Prefix when constructing one compact MessagePack header or scalar byte.
How to use the tool and how it works
- Enter utf8Bytes. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read octet. Use the output convention below.
Require whole utf8Bytes in [0,31]. Return octet = 160+utf8Bytes, combining the fixstr tag with its five-bit byte length.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| utf8Bytes | Supplied UTF-8 payload length in bytes, from zero through 31. | Required. Safe integer; minimum 0; maximum 31. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| octet | Octet | Required. Safe integer. |
{
"input": {
"utf8Bytes": 5
},
"output": {
"octet": 165
}
}Limitations and assumptions
- The length is supplied and counts UTF-8 bytes, not characters. No string encoding, payload or overall MessagePack validation is performed.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete MessagePack serializer for payload encoding, nested structure and interoperable validation.
References
Similar or alternative tools
- Msgpack Positive Fixint Octet
Return octet = value, the positive fixint byte itself.
- MessagePack Fixmap Count Header
Return header = 128+entries for one fixmap key-value-pair count.