Komenda
Komenda is a convenience wrapper to run shell commands in Ruby.
Usage
Run a command:
Komenda.run('date')
The run()
method will block until the sub process finished.
It will expose the output and exit status as a Komenda::Result
value:
result = Komenda.run('date')
result.stdout # => "Tue Nov 26 14:45:03 EST 2013\n"
result.stderr # => ""
result.output # => "Tue Nov 26 14:45:03 EST 2013\n" (combined stdout + stderr)
result.status # => 0
result.success? # => true
result.pid # => 32157
The program and its arguments can be passed as an array:
result = Komenda.run(['echo', '-n', 'hello'])
result.output # => "hello"
The run()
method has a second argument options
, which accepts these optional keys:
env
(Hash): Additional environment variables to set.reset_bundler_env
(Boolean): Reset environment variables from your current Ruby bundle usingBundler.clean_env
. Defaults totrue
.cwd
(String): Directory to change to before running the process.
Advanced usage
The create()
method creates a Process
which can be run()
(or start()
ed as a Thread).
process = Komenda.create('date')
result = process.run
Event callbacks can be registered with Process.on()
, for example for when output is written.
process = Komenda.create('date')
process.on(:stdout) { |output| puts "STDOUT: #{output}" }
result = process.run
The following events are emitted:
.on(:stdout) { |output| }
: When data is available on STDOUT..on(:stderr) { |output| }
: When data is available on STDERR..on(:output) { |output| }
: When data is available on STDOUT or STDERR..on(:exit) { |result| }
: When the process finishes..on(:error) { |exception| }
: When process execution fails (e.g. executable file cannot be found).
Development
Install dependencies:
bundle install
Run the tests:
bundle exec rake spec
TODO
Add options for:
- Passing STDIN
- Making
run()
fail when exit status is not '0'