Portable Snippets

This is a collection of public domain (CC0) code snippets written in C for performing various common tasks which are typically OS, architecture, and/or compiler-dependent. Basically, our goal is to move those annoying preprocessor conditionals from your code to ours.

Modules have no fixed target (such as C89) since that would preclude some functionality; instead, we simply try to provide the widest support we can for each module. If you have a platform which isn't supported for a particular feature but could be, please let us know; we'd be happy to try to work out a way to support it.

Everything is tested continuously with various versions of GCC, Clang, and PGI (on Travis CI), MSVC (on AppVeyor), and Emscripten (on Codefresh):

Currently ready-to-use modules include:

• builtin — use compiler built-ins/intrinsics, or fall back on standard C
• endian — endianness detection and swapping
• atomic — common atomic synchronization operations
• safe-math — overflow-safe integer functions
• exact-int — exact-width integer types (think <stdint.h>)
• clock — cross-platform wall clock, CPU time, and monotonic time

There are also modules which may not yet be ready for widespread use, but would benefit greatly from testing:

• unaligned — fast unaligned loads & stores
• once — one-time initialization
• random — random number generation (3 flavors: cryptographic, reproducible, and fast)
• debug-trap — debugging traps and assertions
• check — assertion checking

Modules can be used in isolation, though some do work better together, so if you can keep the whole repository together instead of just copying a single file we recommend you do so.

Please don't be shy about filing issues about any of these; if you have problems it's likely others will, as well, so we would like to fix them.

If you have something you would like to contribute, please file an issue or pull request. If you'd like to help out by writing something new, take a look at the "enhancement" issues in our issue tracker for ideas.

Some things don't really fit this repository, so here are a few small-ish projects for doing things portably which you may be interested in:

• Hedley — macros to enable compiler-specific features which make your code easier to use, harder to misuse, safer, faster, and more portable.
• parg — Argument parsing similar to getopt/getopt_long. Public domain.
• TinyCThread — Implements the C11 threads API on top of pthreads and the Windows API. zlib license.
• win-iconv — Windows implementation of the iconv API (character set conversion).
• mman-win32 — mman.h (mmap(), etc.) implementation for Windows.

If there is a project you'd like to see added to the list, please file an issue or pull request.