kanerogers / mixlib-shellout

mixin library for subprocess management, output collection

Mixlib::ShellOut

Provides a simplified interface to shelling out yet still collecting both standard out and standard error and providing full control over environment, working directory, uid, gid, etc.

No means for passing input to the subprocess is provided.

Example

Invoke find(1) to search for .rb files:

  find = Mixlib::ShellOut.new("find . -name '*.rb'")
  find.run_command

If all went well, the results are on stdout

  puts find.stdout

find(1) prints diagnostic info to STDERR:

  puts "error messages" + find.stderr

Raise an exception if it didn't exit with 0

  find.error!

Run a command as the www user with no extra ENV settings from /tmp

  cmd = Mixlib::ShellOut.new("apachectl", "start", :user => 'www', :env => nil, :cwd => '/tmp')
  cmd.run_command # etc.

STDIN Example

Invoke crontab to edit user cron:

  # :input only supports simple strings
  crontab_lines = [ "* * * * * /bin/true", "* * * * * touch /tmp/here" ]
  crontab = Mixlib::ShellOut.new("crontab -l -u #{@new_resource.user}", :input => crontab_lines.join("\n"))
  crontab.run_command

Windows Impersonation Example

Invoke crontab to edit user cron:

  whomai = Mixlib::ShellOut.new("whoami.exe", :user => "username", :domain => "DOMAIN", :password => "password")
  whoami.run_command      

Platform Support

Mixlib::ShellOut does a standard fork/exec on Unix, and uses the Win32 API on Windows. There is not currently support for JRuby.

License

Apache 2 Licensed. See LICENSE for full details.

See Also

• Process.spawn in Ruby 1.9
• https://github.com/rtomayko/posix-spawn