# ulid-c

**Repository Path**: ercengsha/ulid-c

## Basic Information

- **Project Name**: ulid-c
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Unlicense
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-05-28
- **Last Updated**: 2025-05-28

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# ULID Library (C99)

This is a library for generating and handling [Universally Unique
Lexicographically Sortable Identifiers][ulid] (ULIDs). On modern
hardware running Linux, it can generate 68 million ULIDs per second
(50 cycles per ULID). Supported operating systems: POSIX and Win32.

This repository also includes a `ulidgen` command line utility for
generating, validating, and inspecting ULIDs.

## Documentation

The complete API documentation is found in `ulid.h`. Here's summary of
the available functions:

```c
int  ulid_generator_init(struct ulid_generator *, int flags);
void ulid_generate(struct ulid_generator *, char[27]);
void ulid_encode(char[27], const unsigned char[16]);
int  ulid_decode(unsigned char[16], const char *);
```

Here are the command line switches for `ulidgen`:

```
usage: ulidgen -G [-prs] [-n N]
       ulidgen -C [-iq] <ULIDs...>
       ulidgen -T [-i] <ULIDs...>
       ulidgen -h
  -G      Generate ULIDs
  -C      Check/validate ULIDs
  -T      Print timestamp from ULIDs
  -h      Display this help message
  -i      (-C|-T) Read ULIDs on standard input
  -n N    (-G) Number of ULIDs to generate [1]
  -p      (-G) Only use 79 random bits to avoid overflow
  -q      (-C) Don't print invalid ULIDs
  -r      (-G) Non-monotonic ULIDs within timestamp
  -s      (-G) Require secure initialization
```

[ulid]: https://github.com/ulid/spec