Adds pledge(2) to crystal.

Add this to your application's shard.yml:

dependencies:
  pledge:
    github: chris-huxtable/pledge.cr

require "pledge"

Partial syscall restrictions:

Process.pledge(:stdio, :rpath, :wpath, :flock)
Process.pledge("stdio", "rpath")

Full restrictions:

Process.pledge()

More information and a list of 'promises' is available in the OpenBSD man pages.

1. Fork it ( https://github.com/chris-huxtable/pledge.cr/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

• Chris Huxtable - creator, maintainer