# troydhanson/uthash

C macros for hash tables and more

Repository: https://github.com/troydhanson/uthash
Canonical: https://ross.abutalabs.com/products/uthash
Language: C
License: NOASSERTION
License Family: other
Last push: 2026-06-25T14:03:11+00:00

## Health v2 (maintenance only)
Score: 72/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 89, release rhythm 35, longevity 100
- inputs: {"age_days": 4986, "days_push": 69, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4764, forks 978 (observed 2026-08-28T04:08:59.149345+00:00)

## What it is
uthash is a header-only C library providing hash table, linked list, and dynamic array implementations via preprocessor macros. It lets C developers add hash-table capabilities to arbitrary structs with minimal boilerplate.

## Use cases
- add a hash table to a C struct
- implement a dictionary in C without writing my own hash table
- C header-only hashmap library
- store key-value pairs in C efficiently
- linked list and dynamic array macros for C

## When to choose
- you need a lightweight, dependency-free hash table in C
- you want header-only data structures you can drop into any project
- you need hash tables keyed on arbitrary struct fields

## When to avoid
- you need thread-safe or lock-free hash tables
- you want a full-featured container library with iterators and allocators
- you're working in a language other than C

## Facets
- artifact type: library
- maturity: maintenance
- function: developer-tools
- domain: developer-tools
- platform: c, cpp, cross-platform
- tags: hash-table, header-only, c-macros, data-structures, linked-list, algorithms

## Member repositories
- troydhanson/uthash (main) score 72

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:59.149345+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:18:50.969919+00:00, confidence not recorded.
  - readme: https://github.com/troydhanson/uthash (fetched 2026-08-28T04:08:59.149345+00:00, sha 1d1d80836b37)
- Data as of 2026-08-30T08:39:29.467469+00:00.