class AwesomeSpawn::CommandLineBuilder

Constants

KEY_REGEX

Public Instance Methods

build(command, params = nil) click to toggle source

Build the full command line.

@param [String] command The command to run @param [Hash,Array] params Optional command line parameters. They can

be passed as a Hash or associative Array. The values are sanitized to
prevent command line injection.  Keys as Symbols are prefixed with `--`,
and `_` is replaced with `-`.

- `{:key => "value"}`            generates `--key value`
- `[[:key, "value"]]`            generates `--key value`
- `{:key= => "value"}`           generates `--key=value`
- `[[:key=, "value"]]`           generates `--key=value` <br /><br />

- `{"--key" => "value"}`         generates `--key value`
- `[["--key", "value"]]`         generates `--key value`
- `{"--key=" => "value"}`        generates `--key=value`
- `[["--key=", "value"]]`        generates `--key=value` <br /><br />

- `{:key_name => "value"}`       generates `--key-name value`
- `[[:key_name, "value"]]`       generates `--key-name value`
- `{:key_name= => "value"}`       generates `--key-name=value`
- `[[:key_name=, "value"]]`       generates `--key-name=value` <br /><br />

- `{"-f" => ["file1", "file2"]}` generates `-f file1 file2`
- `[["-f", "file1", "file2"]]`   generates `-f file1 file2` <br /><br />

- `{:key => nil}`                generates `--key`
- `[[:key, nil]]`                generates `--key`
- `[[:key]]`                     generates `--key` <br /><br />

- `{nil => ["file1", "file2"]}`  generates `file1 file2`
- `[[nil, ["file1", "file2"]]]`  generates `file1 file2`
- `[[nil, "file1", "file2"]]`    generates `file1 file2`
- `[["file1", "file2"]]`         generates `file1 file2`

@return [String] The full command line

# File lib/awesome_spawn/command_line_builder.rb, line 41
def build(command, params = nil)
  params = assemble_params(sanitize(params))
  params.empty? ? command.to_s : "#{command} #{params}"
end

Private Instance Methods

assemble_params(sanitized_params) click to toggle source

# File lib/awesome_spawn/command_line_builder.rb, line 48
def assemble_params(sanitized_params)
  sanitized_params.collect do |group|
    joiner = group.first.to_s.end_with?("=") ? "" : " "
    group.compact.join(joiner)
  end.join(" ")
end

convert_symbol_key(key) click to toggle source

# File lib/awesome_spawn/command_line_builder.rb, line 94
def convert_symbol_key(key)
  "--#{key.to_s.tr("_", "-")}"
end

sanitize(params) click to toggle source

# File lib/awesome_spawn/command_line_builder.rb, line 55
def sanitize(params)
  return [] if params.nil? || params.empty?
  sanitize_associative_array(params.to_a)
end

sanitize_associative_array(assoc_array) click to toggle source

# File lib/awesome_spawn/command_line_builder.rb, line 60
def sanitize_associative_array(assoc_array)
  assoc_array.each.with_object([]) do |item, array|
    array.concat(sanitize_item(item))
  end
end

sanitize_item(item) click to toggle source

# File lib/awesome_spawn/command_line_builder.rb, line 66
def sanitize_item(item)
  case item
  when Array then sanitize_key_values(item[0], item[1..-1])
  when Hash  then sanitize_associative_array(item.to_a)
  else            sanitize_key_values(item, [])
  end
end

sanitize_key(key) click to toggle source

# File lib/awesome_spawn/command_line_builder.rb, line 80
def sanitize_key(key)
  return key if key.nil?
  key = convert_symbol_key(key) if key.kind_of?(Symbol)

  case key
  when String
    return key if key.empty?
    prefix, key, suffix = KEY_REGEX.match(key)[1..3]
    "#{prefix}#{sanitize_value(key)}#{suffix}"
  else
    sanitize_value(key)
  end
end

sanitize_key_values(key, values) click to toggle source

# File lib/awesome_spawn/command_line_builder.rb, line 74
def sanitize_key_values(key, values)
  [[sanitize_key(key), *sanitize_value(values)]]
end

sanitize_value(value) click to toggle source

# File lib/awesome_spawn/command_line_builder.rb, line 98
def sanitize_value(value)
  case value
  when Enumerable
    value.to_a.collect { |i| sanitize_value(i) }.compact
  when NilClass
    value
  else
    value.to_s.shellescape
  end
end