class Augeas::Facade

Wrapper class for the augeas library.

Public Class Methods

Source

# File lib/augeas/facade.rb, line 32
def self.create(opts={}, &block)
  # aug_flags is a bitmask in the underlying library, we add all the
  # values of the flags which were set to true to the default value
  # Augeas::NONE (which is 0)
  aug_flags = defined?(Augeas::NO_ERR_CLOSE) ? Augeas::NO_ERR_CLOSE : Augeas::NONE

  flags = {
    :type_check => Augeas::TYPE_CHECK,
    :no_stdinc => Augeas::NO_STDINC,
    :no_load => Augeas::NO_LOAD,
    :no_modl_autoload => Augeas::NO_MODL_AUTOLOAD,
    :enable_span => Augeas::ENABLE_SPAN
  }
  save_modes = {
    :backup => Augeas::SAVE_BACKUP,
    :newfile => Augeas::SAVE_NEWFILE,
    :noop => Augeas::SAVE_NOOP
  }
  opts.each_key do |key|
    if flags.key? key
      aug_flags |= flags[key]
    elsif key == :save_mode
      if save_modes[opts[:save_mode]]
        aug_flags |= save_modes[opts[:save_mode]]
      else
        raise ArgumentError, "Invalid save mode #{opts[:save_mode]}."
      end
    elsif key != :root && key != :loadpath
      raise ArgumentError, "Unknown argument #{key}."
    end
  end

  aug = Augeas::Facade::open3(opts[:root], opts[:loadpath], aug_flags)

  begin
    aug.send(:raise_last_error)
  rescue
    aug.close
    raise
  end

  if block_given?
    begin
      yield aug
    ensure
      aug.close
    end
  else
    return aug
  end
end

Public Instance Methods

clear (path)

Source

# File lib/augeas/facade.rb, line 149
def clear(path)
  augeas_set(path, nil)
end

Clear the path, i.e. make its value nil

clear_transforms ()

Source

# File lib/augeas/facade.rb, line 180
def clear_transforms
  rm("/augeas/load/*")
end

Clear all transforms under /augeas/load. If load is called right after this, there will be no files under /files

clearm (path, sub)

Source

# File lib/augeas/facade.rb, line 197
def clearm(path, sub)
  setm(path, sub, nil)
end

context ()

Source

# File lib/augeas/facade.rb, line 293
def context
  get('/augeas/context')
end

Get path expression context (from /augeas/context)

context= (path)

Source

# File lib/augeas/facade.rb, line 288
def context=(path)
  set('/augeas/context', path)
end

Set path expression context to path (in /augeas/context)

defnode (name, expr, value=nil)

Source

# File lib/augeas/facade.rb, line 144
def defnode(name, expr, value=nil)
  run_command :augeas_defnode, name, expr, value
end

Define the variable name to the result of evaluating expr, which must be a nodeset. If no node matching expr exists yet, one is created and name will refer to it. When a node is created and value is given, the new node’s value is set to value.

defvar (name, expr)

Source

# File lib/augeas/facade.rb, line 136
def defvar(name, expr)
  run_command :augeas_defvar, name, expr
end

Evaluate expr and set the variable name to the resulting nodeset. The variable can be used in path expressions as $name. Note that expr is evaluated when the variable is defined, not when it is used.

exists (path)

Source

# File lib/augeas/facade.rb, line 90
def exists(path)
  run_command :augeas_exists, path
end

Return true if there is an entry for this path, false otherwise

get (path)

Source

# File lib/augeas/facade.rb, line 85
def get(path)
  run_command :augeas_get, path
end

Get the value associated with path.

insert (path, label, before)

Source

# File lib/augeas/facade.rb, line 283
def insert(path, label, before)
  run_command :augeas_insert, path, label, before
end

Make label a sibling of path by inserting it directly before or after path. The boolean before determines if label is inserted before or after path.

label (path)

Source

# File lib/augeas/facade.rb, line 254
def label(path)
  run_command :augeas_label, path
end

Lookup the label associated with path Raises Augeas::NoMatchError if the path node does not exist

load ()

Source

# File lib/augeas/facade.rb, line 209
def load
  begin
    run_command :augeas_load
  rescue Augeas::CommandExecutionError => e
    raise e, "Loading failed. Search the augeas tree in /augeas//error"+
      "for the actual errors."
  end

  nil
end

Load files according to the transforms in /augeas/load or those defined via transform. A transform Foo is represented with a subtree /augeas/load/Foo. Underneath /augeas/load/Foo, one node labeled ‘lens’ must exist, whose value is the fully qualified name of a lens, for example ‘Foo.lns’, and multiple nodes ‘incl’ and ‘excl’ whose values are globs that determine which files are transformed by that lens. It is an error if one file can be processed by multiple transforms.

match (path)

Source

# File lib/augeas/facade.rb, line 123
def match(path)
  run_command :augeas_match, path
end

Return an Array of all the paths that match the path expression path

Returns an empty Array if no paths were found. Raises an Augeas::InvalidPathError when the path is invalid.

mv (src, dst)

Source

# File lib/augeas/facade.rb, line 231
def mv(src, dst)
  run_command :augeas_mv, src, dst
end

Move node src to dst. src must match exactly one node in the tree. dst must either match exactly one node in the tree, or may not exist yet. If dst exists already, it and all its descendants are deleted. If dst does not exist yet, it and all its missing ancestors are created.

Raises Augeas::NoMatchError if the src node does not exist Raises Augeas::MultipleMatchesError if there were multiple matches in src Raises Augeas::DescendantError if the dst node is a descendant of the src node.

rename (path, label)

Source

# File lib/augeas/facade.rb, line 261
def rename(path, label)
  run_command :augeas_rename, path, label
end

Rename the label of all nodes matching path to label Raises Augeas::NoMatchError if the path node does not exist Raises Augeas::InvalidLabelError if label is invalid

rm (path)

Source

# File lib/augeas/facade.rb, line 115
def rm(path)
  run_command :augeas_rm, path
end

Remove all nodes matching path expression path and all their children. Raises an Augeas::InvalidPathError when the path is invalid.

save ()

Source

# File lib/augeas/facade.rb, line 186
def save
  begin
    run_command :augeas_save
  rescue Augeas::CommandExecutionError => e
    raise e, 'Saving failed. Search the augeas tree in /augeas//error ' <<
      'for the actual errors.'
  end

  nil
end

Write all pending changes to disk. Raises Augeas::CommandExecutionError if saving fails.

set (path, *values)

Source

# File lib/augeas/facade.rb, line 97
def set(path, *values)
  values.flatten.each { |v| run_command :augeas_set, path, v }
end

Set one or multiple elements to path. Multiple elements are mainly sensible with a path like …/array, since this will append all elements.

setm (base, sub, value)

Source

# File lib/augeas/facade.rb, line 108
def setm(base, sub, value)
  run_command :augeas_setm, base, sub, value
end

base the base node sub the subtree relative to the base value the value for the nodes

span (path)

Source

# File lib/augeas/facade.rb, line 240
def span(path)
  run_command :augeas_span, path
end

Get the filename, label and value position in the text of this node

Raises Augeas::NoMatchError if the node could not be found Raises Augeas::NoSpanInfo if the node associated with path doesn’t belong to a file or doesn’t exist

srun (text)

Source

# File lib/augeas/facade.rb, line 248
def srun(text)
  run_command(:augeas_srun, text)
end

Run one or more newline-separated commands specified by text, returns an array of [successful_commands_number, output] or

-2, output: in case ‘quit’ command has been encountered.

Raises Augeas::CommandExecutionError if gets an invalid command

text_retrieve (lens, node_in, path, node_out)

Source

# File lib/augeas/facade.rb, line 275
def text_retrieve(lens, node_in, path, node_out)
  run_command :augeas_text_retrieve, lens, node_in, path, node_out
end

Transform the tree at path into a string lens lens and store it in the node node_out, assuming the tree was initially generated using the value of node node_in. path, node_in and node_out are path expressions.

text_store (lens, node, path)

Source

# File lib/augeas/facade.rb, line 268
def text_store(lens, node, path)
  run_command :augeas_text_store, lens, node, path
end

Use the value of node node as a string and transform it into a tree using the lens lens and store it in the tree at path, which will be overwritten. path and node are path expressions.

touch (path)

Source

# File lib/augeas/facade.rb, line 128
def touch(path)
  set(path, nil) if match(path).empty?
end

Create the path with empty value if it doesn’t exist

transform (hash)

Source

# File lib/augeas/facade.rb, line 162
def transform(hash)
  lens = hash[:lens]
  name = hash[:name]
  incl = hash[:incl]
  excl = hash[:excl]
  raise ArgumentError, "No lens specified" unless lens
  raise ArgumentError, "No files to include" unless incl
  name = lens.split(".")[0].sub("@", "") unless name

  xfm = "/augeas/load/#{name}/"
  set(xfm + "lens", lens)
  set(xfm + "incl[last()+1]", incl)
  set(xfm + "excl[last()+1]", excl) if excl
end

Add a transform under /augeas/load

The HASH can contain the following entries

:lens - the name of the lens to use
:name - a unique name; use the module name of the LENS

when omitted

:incl - a list of glob patterns for the files to transform
:excl - a list of the glob patterns to remove from the

list that matches :incl