nanoid.h

A 2.3 Kb single header NanoID implementation in C

What is NanoID?

NanoID is a tiny, secure URL-friendly unique string ID generator.
It's safe. It uses cryptographically strong random APIs that guarantees proper distribution of symbols.
And it's compact. It uses a larger alphabet than the standard UUID (A-Za-z0-9_-), and has a similar number of unique IDs in just 21 symbols instead of 36.

Usage

#include "nanoid.h"

This header file exposes 3 functions.

simple() - generate an id of default length (21) using the default character set

char *id = simple(); // _n7XMO8sd8lCDnDLmyezf

generate(int size) - generate an id of custom length using the default character list

char *id = generate(5); // xgTpQ

custom(char custom_alphs[], int size) - generate an id of custom length using a custom character set

char custom_alphs[] = "abcde";
char *id = custom(custom_alphs, 7); // ecbebec

New Features

Added safer functions, to use them you can prefix the default functions with safe_ for example you can use the safe version of by executing: safe_simple(). The new safe functions use /dev/urandom as a seed to generate the random block that is returned to the user. Due to this the header file is 1.1 Kb larger than the original which was 1.2 Kb