System Call

A simple wrapper around Ruby's Open3 to call CLI programs and process their output.

Installation

Add this line to your application's Gemfile:

gem 'systemcall'

And then execute:

$ bundle

Or install it yourself as:

$ gem install systemcall

Usage

Functional

To run a CLI program use the following method:

SystemCall.call('which', 'bash')
SystemCall.call(['which', 'bash'])
# => #<SystemCall::Result ...>

A command that has been executed returns a result object. When the command has run successfully, the result may look like so:

result = SystemCall.call('which', 'bash')
result.exit_code # => 0
result.success? # => true
result.error? # => false
result.success_result # => "/bin/bash"
result.error_result # => ""
result.result # => "/bin/bash"

When the command failed, it may look like this:

result = SystemCall.call('which', 'unknown')
result.exit_code # => 1
result.success? # => false
result.error? # => true

In critical cases, the method may also raise:

SystemCall.call('unknown')
# ** (Errno::ENOENT) No such file or directory - unknown

Mixin

Alternatively, you can include the SystemCall module directly in your classes or modules. The included method name is system_call but the API is the same as for SystemCall.call.

include SystemCall

system_call('which', 'bash')
system_call(['which', 'bash'])

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/tlux/systemcall.

License

The gem is available as open source under the terms of the

MIT License.