Class: Cri::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/SANStore/cri/base.rb

Overview

Cri::Base is the central class representing a commandline tool. It has a list of commands.

Direct Known Subclasses

SANStore::CLI::Base

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(tool_name) ⇒ Base

Creates a new instance of the commandline tool.



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# File 'lib/SANStore/cri/base.rb', line 14

def initialize(tool_name)
  @tool_name = tool_name

  @commands = []
end

Instance Attribute Details

#commands ⇒ Object (readonly)

The CLI’s list of commands (should also contain the help command)



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# File 'lib/SANStore/cri/base.rb', line 8

def commands
  @commands
end

#help_command ⇒ Object

The CLI’s help command (required)



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# File 'lib/SANStore/cri/base.rb', line 11

def help_command
  @help_command
end

Instance Method Details

#add_command(command) ⇒ Object

Adds the given command to the list of commands. Adding a command will also cause the command’s base to be set to this instance.



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# File 'lib/SANStore/cri/base.rb', line 133

def add_command(command)
  @commands << command
  command.base = self
end

#command_named(name) ⇒ Object

Returns the command with the given name.



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# File 'lib/SANStore/cri/base.rb', line 96

def command_named(name)
  # Find by exact name or alias
  command = @commands.find { |c| c.name == name or c.aliases.include?(name) }
  return command unless command.nil?

  # Find by approximation
  commands = @commands.select { |c| c.name[0, name.length] == name }
  if commands.length > 1
    $stderr.puts "#{@tool_name}: '#{name}' is ambiguous:"
    $stderr.puts "  #{commands.map { |c| c.name }.join(' ') }"
    exit 1
  elsif commands.length == 0
    $stderr.puts "#{@tool_name}: unknown command '#{name}'\n"
    show_help
    exit 1
  else
    return commands[0]
  end
end

#global_option_definitions ⇒ Object

Returns the list of global option definitionss.



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# File 'lib/SANStore/cri/base.rb', line 127

def global_option_definitions
  []
end

#handle_option(option) ⇒ Object

Handles the given optio



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# File 'lib/SANStore/cri/base.rb', line 139

def handle_option(option)
  false
end

#run(args) ⇒ Object

Parses the given commandline arguments and executes the requested command.



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# File 'lib/SANStore/cri/base.rb', line 22

def run(args)
  # Check arguments
  if args.length == 0
    @help_command.run([], [])
    exit 1
  end

  # Partition options
  opts_before_command         = []
  command_name                = nil
  opts_and_args_after_command = []
  stage = 0
  args.each do |arg|
    # Update stage if necessary
    stage = 1 if stage == 0 && !is_option?(arg)

    # Add
    opts_before_command << arg         if stage == 0
    command_name = arg                 if stage == 1
    opts_and_args_after_command << arg if stage == 2

    # Update stage if necessary
    stage = 2 if stage == 1
  end

  # Handle options before command
  begin
    parsed_arguments = Cri::OptionParser.parse(opts_before_command, global_option_definitions)
  rescue Cri::OptionParser::IllegalOptionError => e
    $stderr.puts "illegal option -- #{e}"
    exit 1
  end
  parsed_arguments[:options].keys.each do |option|
    handle_option(option)
  end

  # Get command
  if command_name.nil?
    $stderr.puts "no command given"
    exit 1
  end
  command = command_named(command_name)
  if command.nil?
    $stderr.puts "no such command: #{command_name}"
    exit 1
  end

  # Parse arguments
  option_definitions = command.option_definitions + global_option_definitions
  begin
    parsed_arguments = Cri::OptionParser.parse(opts_and_args_after_command, option_definitions)
  rescue Cri::OptionParser::IllegalOptionError => e
    $stderr.puts "illegal option -- #{e}"
    exit 1
  rescue Cri::OptionParser::OptionRequiresAnArgumentError => e
    $stderr.puts "option requires an argument -- #{e}"
    exit 1
  end

  # Handle global options
  global_options = global_option_definitions.map { |o| o[:long] }
  global_options.delete_if { |o| !parsed_arguments[:options].keys.include?(o.to_sym) }
  global_options.each { |o| handle_option(o.to_sym) }

  if parsed_arguments[:options].has_key?(:help)
    # Show help for this command
    show_help(command)
  else
    # Run command
    command.run(parsed_arguments[:options], parsed_arguments[:arguments])
  end
end

#show_help(command = nil) ⇒ Object

Shows the help text for the given command, or shows the general help text if no command is given.



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# File 'lib/SANStore/cri/base.rb', line 118

def show_help(command=nil)
  if command.nil?
    @help_command.run([], [])
  else
    @help_command.run([], [ command.name ])
  end
end