Class: UserChoices::PosixCommandLineSource

Inherits:
CommandLineSource show all
Defined in:
lib/user-choices/command-line-source.rb

Overview

Process command-line choices according to POSIX rules. Consider

ruby copy.rb file1 –odd-file-name

Ordinarily, that’s permuted so that –odd-file-name is expected to be an option or switch, not an argument. One way to make CommandLineSource parsing treat it as an argument is to use a – to signal the end of option parsing:

ruby copy.rb – file1 –odd-file-name

Another is to rely on the user to set environment variable POSIXLY_CORRECT.

Since both of those require the user to do something, they’re error-prone.

Another way is to use this class, which obeys POSIX-standard rules. Under those rules, the first word on the command line that does not begin with a dash marks the end of all options. In that case, the first command line above would parse into two arguments and no options.

Instance Attribute Summary

Attributes inherited from AbstractSource

#external_names

Instance Method Summary collapse

Methods inherited from CommandLineSource

#add_help_line, #adjust, #apply, #deep_copy, #exit_upon_error, #help, #help_banner, #initialize, #source, #usage, #use_strategy, #uses_arg, #uses_arglist, #uses_option, #uses_optional_arg, #uses_switch

Methods inherited from AbstractSource

#adjust, #apply, #each_conversion, #initialize, #source

Constructor Details

This class inherits a constructor from UserChoices::CommandLineSource

Instance Method Details

#fill ⇒ Object 



211
212
213
214
215
216
217
218
219
 
# File 'lib/user-choices/command-line-source.rb', line 211

def fill
  begin
    already_set = ENV.include?('POSIXLY_CORRECT')
    ENV['POSIXLY_CORRECT'] = 'true' unless already_set
    super
  ensure
    ENV.delete('POSIXLY_CORRECT') unless already_set
  end
end