Class: Subcommand

Inherits:
Object
  • Object
show all
Defined in:
lib/habits/subcommand.rb

Overview

A minimal command line parser for subcommands. CMD SUBCOMMAND ARG1 ARG2 …

Defined Under Namespace

Classes: Cmd

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Subcommand

Returns a new instance of Subcommand.



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# File 'lib/habits/subcommand.rb', line 43

def initialize
  @default = nil
  @subs = {}
  @auto_help = false
end

Instance Attribute Details

#auto_help ⇒ Object

Returns the value of attribute auto_help.



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# File 'lib/habits/subcommand.rb', line 41

def auto_help
  @auto_help
end

#subs ⇒ Object (readonly)

Returns the value of attribute subs.



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# File 'lib/habits/subcommand.rb', line 6

def subs
  @subs
end

Instance Method Details

#default(&blk) ⇒ Object

Set the default command to be called when just the executable is run.



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# File 'lib/habits/subcommand.rb', line 57

def default(&blk)
  raise "No block given" unless blk
  @default = blk
end

#default=(cmd_name) ⇒ Object

Set the default command to be one of the registered subcommands



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# File 'lib/habits/subcommand.rb', line 63

def default=(cmd_name)
  raise "No subcommand #{cmd_name} registerd" if @subs[cmd_name].nil?
  @default = @subs[cmd_name].blk
end

#help ⇒ Object

Print help of available commands.



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# File 'lib/habits/subcommand.rb', line 93

def help
  puts "\nUsage: #{File.basename($0)} {command} arg1 arg2 ...\n\nCommand        Args"+
       ' '*32+"Description"
  @subs.keys.sort.each do |name|
    printf("  %-12s %-35s %s\n", name, @subs[name].args_str, @subs[name].desc)
  end
  puts
  true
end

#parse(args = ARGV) ⇒ Object

Parse command line arguments according to registered commands.



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# File 'lib/habits/subcommand.rb', line 69

def parse(args=ARGV)
  if args.size == 0
    @default.call if @default
    return
  end
  
  sub = @subs[args.shift]
  
  if sub.nil?
    puts "Unknown command."
    help if auto_help
    return
  end
  
  begin
    sub.parse(args)
    sub.call
  rescue Exception => e
    puts e.message
    help if auto_help
  end
end

#register(cmd_name, args, desc, &blk) ⇒ Object

Register a command with name, arguments, description, and block (blk). The block is called with as many input args as you defined in ‘args’



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# File 'lib/habits/subcommand.rb', line 51

def register(cmd_name, args, desc, &blk)
  @subs ||= {}
  @subs[cmd_name] = Cmd.new(args, desc, blk)
end