Question

我正在浏览ruby中的OptionsParser tutorial。有一行我很困惑的代码：

option_parser = OptionParser.new do |opt|
.
.
.
server_list = %w[a b c]
opt.on("-s SERVERS","--servers SERVERS", server_list, "which server will start between #{server_list.join(',')}") do |servers|
  options[:servers] = servers
end

我理解OptionParser#on可以将值转换为例如：

定义的类型

.
.
.
opt.on("-e","--environment ENVIRONMENT",Numeric, "which environment you want server run") do |environment|
  puts environment #=> Fixnum
  options[:environment] = environment
end

但是我还没弄清楚如何成功运行使用OptionParser的ruby程序，如上所示。请参阅下文，了解我的尝试。

➜  ruby-cli cat 04-with_optparse_convert_values
#!/usr/bin/env ruby

require 'optparse'

options = {}

option_parser = OptionParser.new do |opt|
  opt.banner = "Usage: cats"

  opt.on("-e", "--environment ENVIRONMENT", Numeric, "environment to run") do |env|
    puts "env.class"
    p env.class
    options[:environment] = env
  end

  opt.on("--delay N", Float, "Delay N seconds before executing") do |n|
    options[:delay] = n
  end

  opt.on("-j x,y,z","--jurisdictions x,y,z", Array,
  "which jurisdiction will start") do |jurisdictions|
    options[:jurisdictions] = jurisdictions
  end

  server_list = %w[a b c]
  opt.on("-s SERVERS","--servers SERVERS", server_list,
  "which server will start between #{server_list.join(',')}") do |servers|
    options[:servers] = servers
  end

end

option_parser.parse!
p options
➜  ruby-cli ./04-with_optparse_convert_values -j cats,and,dogs
{:jurisdictions=>["cats", "and", "dogs"]}
➜  ruby-cli ./04-with_optparse_convert_values -j cats,and,dogs -s cats,and,dogs
./04-with_optparse_convert_values:33:in `<main>': invalid argument: -s cats,and,dogs (OptionParser::InvalidArgument)
➜  ruby-cli ./04-with_optparse_convert_values -j cats,and,dogs -s cats
./04-with_optparse_convert_values:33:in `<main>': invalid argument: -s cats (OptionParser::InvalidArgument)
➜  ruby-cli ./04-with_optparse_convert_values -j cats,and,dogs -s "cats,and,dogs"
./04-with_optparse_convert_values:33:in `<main>': invalid argument: -s cats,and,dogs (OptionParser::InvalidArgument)
➜  ruby-cli ./04-with_optparse_convert_values -j cats,and,dogs -s "cats\nand\ndogs"
./04-with_optparse_convert_values:33:in `<main>': invalid argument: -s cats\nand\ndogs (OptionParser::InvalidArgument)
➜  ruby-cli ARRAY=(cats and dogs)
➜  ruby-cli ./04-with_optparse_convert_values -j cats,and,dogs -s ${ARRAY[\*]}
./04-with_optparse_convert_values:33:in `<main>': invalid argument: -s cats (OptionParser::InvalidArgument)
➜  ruby-cli

Answer 1

server_list = %w[a b c]
opt.on("-s SERVERS","--servers SERVERS", server_list,
"which server will start between #{server_list.join(',')}") do |servers|
  options[:servers] = servers
end

提供一系列＆＃34;服务器＆＃34;通过命令行选项-s进行选择，因此，./04-with_optparse_convert_values -s cats不起作用，因为它不是其中一个选项，而是a，b或{ {1}}会。例如：

在这种情况下，OptionsParser做了什么？

1 个答案: