Class: CommandLine

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

Constant Summary collapse

FLAG_1 = 
0
FLAG_2 = 
1
ACCESSOR = 
2
DISP_NAME = 
3
REQUIRED = 
4
DEFAULT = 
5
DOC = 
6
CHECK = 
7
@@add_help = 
true

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(definition) ⇒ CommandLine

definition

:command, nil, <accessor>, <display name>, <required?>, <default>, <doc>, <check allowed commands>

command is a subcommand, cf. ‘svn help`,

<flag1>, <flag2/nil>, <accessor>, <display name>, <required?>, <default>, <doc>, <check: optional>

commandline taking arguments, e.g. ‘mv src target` are specified like this:

:args, nil, <accessor>, <display name>, <required>, <default>, <doc>, <check: optional>

the entire rest of the commandline arg array after the first unrecognized options will then be available under ‘cmdline.<accessor>` the check proc will either be able to check the entire array or, if that fails with an exception, will test each element individually.



34
35
36
37
38
39
 
# File 'lib/cmdline.rb', line 34

def initialize definition
	self.definition= definition
	@output_io ||= STDERR
	@exit_on_usage=true

end

Class Method Details

.add_help=(bool) ⇒ Object 



18
19
20
 
# File 'lib/cmdline.rb', line 18

def self.add_help= bool
	@@add_help=bool
end

Instance Method Details

#definition=(definition) ⇒ Object 



53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
 
# File 'lib/cmdline.rb', line 53

def definition= definition
	definition.push(["-h", "--help", :help, false,  false, nil, "print this message"]) if @@add_help
	cl = class << self; self; end
	# add an accessor to self for each definition.
	cl.instance_eval { attr_accessor *definition.map{|arg_def| arg_def[ACCESSOR]} }
	

	definition.each {|arg_def|
		#check if cmdline takes a command
		if arg_def[FLAG_1]==:command
			@has_command = true
		end
		#set default values
		set arg_def[ACCESSOR], arg_def[DEFAULT]
	}

	@definition=definition

	class << @definition
		def retrieve_flag flag
			find { |arg|
				arg[FLAG_1]==flag || arg[FLAG_2]==flag
			}
		end
	end

end

#exit_on_usage=(bool) ⇒ Object

whether ‘exit` will be called to terminate the program if `usage` is called. Default behaviour is to call `exit` If this behaviour is turned off, a call to usage will result in an exception instead.



49
50
51
 
# File 'lib/cmdline.rb', line 49

def exit_on_usage= bool
	@exit_on_usage= bool
end

#output=(io) ⇒ Object 



41
42
43
 
# File 'lib/cmdline.rb', line 41

def output= io
	@output_io = io
end

#parse(args = ARGV) ⇒ Object 



145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
 
# File 'lib/cmdline.rb', line 145

def parse args=ARGV
	@found = []
	i=0
	# handle svn like command
	if definition = @definition.retrieve_flag(:command)

		if definition[REQUIRED] && args.length==0
			usage "missing mandatory command"
		elsif test_def = @definition.retrieve_flag(args[i])
			usage "missing mandatory command" if definition[REQUIRED] 
		else
		
			check definition, args[i]
			set definition[ACCESSOR], args[i]

			i+=1
		end	
			
	end

	while i<args.length do
		@found.push args[i]
		if definition = @definition.retrieve_flag(args[i]) # is there a definition for this flag?
			if definition[DISP_NAME]
				# takes a parameter
				check definition, args[i+=1]
				set definition[ACCESSOR], args[i]	
			else
				# plain flag
				set definition[ACCESSOR], true
			end	
		else	# are unknown flags ok? i.e. is there an :args definition.
			if definition = @definition.retrieve_flag(:args)
				check_args definition, args[i, args.length-1]
				set definition[ACCESSOR], args[i, args.length-1]
				break
			end
			usage "unknown flag: #{args[i]}"
		end
		i+=1
	end

	if definition = @definition.retrieve_flag(:args) # are :args required?
		if definition[REQUIRED]
			args = self.send definition[ACCESSOR]
			usage "missing mandatory args" unless args && args.length>1
		end
	end
	
	usage if self.help # call usage if the -h/--help flag was set.

	# check all mandatory args are present.
	@definition.each {|definition|

		if definition[REQUIRED] && !([:command, :args].include? definition[FLAG_1])
			usage "missing mandatory flag #{definition [FLAG_1]?definition[FLAG_1]:definition[FLAG_2]}" unless ((@found.include? definition[FLAG_1]) || (@found.include? definition[FLAG_2]))
		end
	}
end

#usage(mes = "") ⇒ Object

definition



81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
 
# File 'lib/cmdline.rb', line 81

def usage mes=""
	raise mes unless @exit_on_usage

	
	# put together usage information for flags.	
	max = 0			#max flag length for formatting
	has_required=false
	has_options=false
	us = @definition.map {|arg_def|
		if arg_def[FLAG_1] == :command 
			flag=:command
		elsif arg_def[FLAG_1] == :args
			flag=:args	
		else
	# create a usage string of the form:
	#   -f/-flag <value>* must start with a number
	# for each definition. (commands and args are treated seperately)		
			flag = "#{arg_def[FLAG_1]}"
			flag << "/#{arg_def[FLAG_2]}" if arg_def[FLAG_2]
			flag << " <#{arg_def[DISP_NAME]}>" if arg_def[DISP_NAME]
			flag << "*" if arg_def[REQUIRED]
			has_required = true if arg_def[REQUIRED]
			has_options = true
			max = max > flag.length ? max : flag.length
		end
		[flag, arg_def[DOC]]
	}
	
	usage = "usage: #{$0}"
	
	if command=@definition.retrieve_flag(:command)
		fmt = command[REQUIRED] ? " %s" : " [%s]"
		usage << sprintf(fmt,command[DISP_NAME])
	end
	
	if has_options
		usage << (has_required ? " options" : " [options]")
	end
	
	args_doc=false
	if command=@definition.retrieve_flag(:args)
		fmt = command[REQUIRED] ? " %s" : " [%s]"
		usage << sprintf(fmt,command[DISP_NAME])
		args_doc = "#{command[DISP_NAME]}: #{command[DOC]}"
	end
	usage << "\n"

	us.each { |arg_def|
		if arg_def[0].kind_of? String
			usage << sprintf("  %-#{max}s %s\n", arg_def[0], arg_def[1]) 
		elsif arg_def[0] == :command
			# command 
			usage << arg_def[1] if arg_def[1] 
		end

	}
	@output_io.puts usage
	@output_io.puts "* required flags" if has_required
	@output_io.puts "\n#{args_doc}" if args_doc
	@output_io.puts
	@output_io.puts mes
	exit 
end