Module: Chef::Sugar::Shell

Extended by:
Shell
Included in:
Shell
Defined in:
lib/chef/sugar/shell.rb

Instance Method Summary collapse

Instance Method Details

#dev_null(node) ⇒ String

The platform-specific output path to /dev/null.



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# File 'lib/chef/sugar/shell.rb', line 53

def dev_null(node)
  Chef::Sugar::PlatformFamily.windows?(node) ? 'NUL' : '/dev/null'
end

#installed?(cmd) ⇒ Boolean

Boolean method to check if a command line utility is installed.



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# File 'lib/chef/sugar/shell.rb', line 66

def installed?(cmd)
  !which(cmd).nil?
end

#installed_at_version?(cmd, expected_version, flag = '--version') ⇒ Boolean

Checks if the given binary is installed and exists at the given version. Also see #version_for.



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# File 'lib/chef/sugar/shell.rb', line 85

def installed_at_version?(cmd, expected_version, flag = '--version')
  return false if !installed?(cmd)

  version = version_for(cmd, flag)
  return false if version.nil?

  if expected_version.is_a?(Regexp)
    !version.match(expected_version).nil?
  else
    version.include?(expected_version)
  end
end

#version_for(cmd, flag = '--version') ⇒ String

The version for a given command. This method does NOT check if the command exists! It is assumed the command existence has been checked with which or similar. To simply check if an installed version is acceptable, please see installed_at_version.

Assumptions:

1. The command exists.
2. The command outputs version information to +$stdout+ or +$stderr+.
   Did you know that java outputs its version to $stderr?



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# File 'lib/chef/sugar/shell.rb', line 118

def version_for(cmd, flag = '--version')
  cmd = Mixlib::ShellOut.new("#{cmd} #{flag}")
  cmd.run_command
  cmd.error!
  [cmd.stdout.strip, cmd.stderr.strip].join("\n")
end

#which(cmd) ⇒ String?

Finds a command in $PATH



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# File 'lib/chef/sugar/shell.rb', line 33

def which(cmd)
  if Pathname.new(cmd).absolute?
    File.executable?(cmd) ? cmd : nil
  else
    paths = ENV['PATH'].split(::File::PATH_SEPARATOR) + %w(/bin /usr/bin /sbin /usr/sbin)

    paths.each do |path|
      possible = File.join(path, cmd)
      return possible if File.executable?(possible)
    end

    nil
  end
end