lukateras / nanoid.h

Sitnik's Nano ID as a 275-byte C header

Nano ID for C

Tiny, secure, URL-friendly unique string ID generator for C.

• Small. 270 bytes. Header-only. Depends only on libc.
• Safe. Uses getentropy(3), a modern, reliable, secure randomness source.
• Short IDs. While UUIDs are 36 chars, similarly unique Nano IDs are just 21 thanks to the larger alphabet.
• Portable. Nano ID has been ported to 20+ programming languages.

#include <nanoid.h>

void main() {
  char *id = NANOID(); // e.g. "V1StGXR8_Z5jdHi6B-myT"

  if (id)
    puts(id);
}

Overview

Works out of the box on Linux, Android, macOS, iOS, OpenBSD, FreeBSD, NetBSD, Illumos, Fuchsia, and WASI. Windows support requires a getentropy(3) compatibility shim.

For details, consult nanoid(3) and nanoidgen(1) man pages.

Documentation

• function char *nanoid(size_t length)

  Generates a Nano ID of the given length ≤ 256.

  Returns a newly allocated null-terminated string with the ID, or NULL if calloc(3) or getentropy(3) fail.

• macro NANOID()

  Generates a Nano ID of the default length.

  Equivalent to nanoid(21).

Attribution

Port of Nano ID by Andrey Sitnik.

Original logo by Anton Lovchikov.

Social preview background texture from Plastic Bag Samples by TuomoDesign.

Social preview logo assistance by Tanya Nevskaya.