在Ruby脚本中解析命令行参数

I want to call a Ruby script from the command line, and pass in parameters that are key/value pairs.

我想从命令行调用Ruby脚本，并传入键/值对的参数。

Command line call:

命令行调用：

$ ruby my_script.rb --first_name=donald --last_name=knuth

my_script.rb:

my_script.rb：

puts args.first_name + args.last_name

What is the standard Ruby way to do this? In other languages I usually have to use an option parser. In Ruby I saw we have ARGF.read, but that does not seem to work key/value pairs like in this example.

什么是标准的Ruby方法呢？在其他语言中，我通常必须使用选项解析器。在Ruby中我看到我们有ARGF.read，但这似乎不像这个例子那样工作键/值对。

OptionParser looks promising, but I can't tell if it actually supports this case.

OptionParser看起来很有希望，但我不知道它是否真的支持这种情况。

4 个解决方案

#1

Based on the answer by @MartinCortez here's a short one-off that makes a hash of key/value pairs, where the values must be joined with an = sign. It also supports flag arguments without values:

基于@MartinCortez的答案，这是一个简短的一次性，它产生键/值对的散列，其中值必须用=符号连接。它还支持没有值的标志参数：

args = Hash[ ARGV.join(' ').scan(/--?([^=\s]+)(?:=(\S+))?/) ]

…or alternatively…

......或者......

args = Hash[ ARGV.flat_map{|s| s.scan(/--?([^=\s]+)(?:=(\S+))?/) } ]

Called with -x=foo -h --jim=jam it returns {"x"=>"foo", "h"=>nil, "jim"=>"jam"} so you can do things like:

用-x = foo -h -jim = jam调用它返回{“x”=>“foo”，“h”=> nil，“jim”=>“jam”}所以你可以这样做：

puts args['jim'] if args.key?('h')
#=> jam

---

While there are multiple libraries to handle this—including GetoptLong included with Ruby—I personally prefer to roll my own. Here's the pattern I use, which makes it reasonably generic, not tied to a specific usage format, and flexible enough to allow intermixed flags, options, and required arguments in various orders:

虽然有多个库可以处理这个 - 包括Ruby中包含的GetoptLong - 我个人更喜欢自己动手。这是我使用的模式，它使其合理通用，不依赖于特定的使用格式，并且足够灵活，允许在各种顺序中混合使用标记，选项和必需参数：

USAGE = <<ENDUSAGE
Usage:
   docubot [-h] [-v] [create [-s shell] [-f]] directory [-w writer] [-o output_file] [-n] [-l log_file]
ENDUSAGE

HELP = <<ENDHELP
   -h, --help       Show this help.
   -v, --version    Show the version number (#{DocuBot::VERSION}).
   create           Create a starter directory filled with example files;
                    also copies the template for easy modification, if desired.
   -s, --shell      The shell to copy from.
                    Available shells: #{DocuBot::SHELLS.join(', ')}
   -f, --force      Force create over an existing directory,
                    deleting any existing files.
   -w, --writer     The output type to create [Defaults to 'chm']
                    Available writers: #{DocuBot::Writer::INSTALLED_WRITERS.join(', ')}
   -o, --output     The file or folder (depending on the writer) to create.
                    [Default value depends on the writer chosen.]
   -n, --nopreview  Disable automatic preview of .chm.
   -l, --logfile    Specify the filename to log to.

ENDHELP

ARGS = { :shell=>'default', :writer=>'chm' } # Setting default values
UNFLAGGED_ARGS = [ :directory ]              # Bare arguments (no flag)
next_arg = UNFLAGGED_ARGS.first
ARGV.each do |arg|
  case arg
    when '-h','--help'      then ARGS[:help]      = true
    when 'create'           then ARGS[:create]    = true
    when '-f','--force'     then ARGS[:force]     = true
    when '-n','--nopreview' then ARGS[:nopreview] = true
    when '-v','--version'   then ARGS[:version]   = true
    when '-s','--shell'     then next_arg = :shell
    when '-w','--writer'    then next_arg = :writer
    when '-o','--output'    then next_arg = :output
    when '-l','--logfile'   then next_arg = :logfile
    else
      if next_arg
        ARGS[next_arg] = arg
        UNFLAGGED_ARGS.delete( next_arg )
      end
      next_arg = UNFLAGGED_ARGS.first
  end
end

puts "DocuBot v#{DocuBot::VERSION}" if ARGS[:version]

if ARGS[:help] or !ARGS[:directory]
  puts USAGE unless ARGS[:version]
  puts HELP if ARGS[:help]
  exit
end

if ARGS[:logfile]
  $stdout.reopen( ARGS[:logfile], "w" )
  $stdout.sync = true
  $stderr.reopen( $stdout )
end

# etc.

#2

Ruby's built-in OptionParser does this nicely. Combine it with OpenStruct and you're home free:

Ruby的内置OptionParser可以很好地完成这项工作。将它与OpenStruct结合使用，您可以免费上网：

require 'optparse'

options = {}
OptionParser.new do |opt|
  opt.on('--first_name FIRSTNAME') { |o| options[:first_name] = o }
  opt.on('--last_name LASTNAME') { |o| options[:last_name] = o }
end.parse!

puts options

options will contain the parameters and values as a hash.

options将包含参数和值作为哈希。

Saving and running that at the command line with no parameters results in:

在没有参数的命令行中保存并运行它会导致：

$ ruby test.rb
{}

Running it with parameters:

使用参数运行它：

$ ruby test.rb --first_name=foo --last_name=bar
{:first_name=>"foo", :last_name=>"bar"}

That example is using a Hash to contain the options, but you can use an OpenStruct which will result in usage like your request:

该示例使用Hash来包含选项，但您可以使用OpenStruct，这将导致像您的请求一样使用：

require 'optparse'
require 'ostruct'

options = OpenStruct.new
OptionParser.new do |opt|
  opt.on('-f', '--first_name FIRSTNAME', 'The first name') { |o| options.first_name = o }
  opt.on('-l', '--last_name LASTNAME', 'The last name') { |o| options.last_name = o }
end.parse!

puts options.first_name + ' ' + options.last_name

$ ruby test.rb --first_name=foo --last_name=bar
foo bar

It even automatically creates your -h or --help option:

它甚至会自动创建-h或--help选项：

$ ruby test.rb -h
Usage: test [options]
        --first_name FIRSTNAME
        --last_name LASTNAME

You can use short flags too:

你也可以使用短旗：

require 'optparse'

options = {}
OptionParser.new do |opt|
  opt.on('-f', '--first_name FIRSTNAME') { |o| options[:first_name] = o }
  opt.on('-l', '--last_name LASTNAME') { |o| options[:last_name] = o }
end.parse!

puts options

Running that through its paces:

通过它的步伐运行：

$ ruby test.rb -h
Usage: test [options]
    -f, --first_name FIRSTNAME
    -l, --last_name LASTNAME
$ ruby test.rb -f foo --l bar
{:first_name=>"foo", :last_name=>"bar"}

It's easy to add inline explanations for the options too:

为选项添加内联解释也很容易：

OptionParser.new do |opt|
  opt.on('-f', '--first_name FIRSTNAME', 'The first name') { |o| options[:first_name] = o }
  opt.on('-l', '--last_name LASTNAME', 'The last name') { |o| options[:last_name] = o }
end.parse!

and:

和：

$ ruby test.rb -h
Usage: test [options]
    -f, --first_name FIRSTNAME       The first name
    -l, --last_name LASTNAME         The last name

OptionParser also supports converting the parameter to a type, such as an Integer or an Array. Refer to the documentation for more examples and information.

OptionParser还支持将参数转换为类型，例如Integer或Array。有关更多示例和信息，请参阅文档。

You should also look at the related questions list to the right:

您还应该查看右侧的相关问题列表：

• "Really Cheap Command-Line Option Parsing in Ruby"
• “真正便宜的命令行选项在Ruby中解析”
• "Pass variables to Ruby script via command line"
• “通过命令行将变量传递给Ruby脚本”

#3

A bit of standard Ruby Regexp in myscript.rb:

myscript.rb中的一些标准Ruby Regexp：

args = {}

ARGV.each do |arg|
  match = /--(?<key>.*?)=(?<value>.*)/.match(arg)
  args[match[:key]] = match[:value] # e.g. args['first_name'] = 'donald'
end

puts args['first_name'] + ' ' + args['last_name']

And on the command line:

并在命令行上：

$ ruby script.rb --first_name=donald --last_name=knuth

$ ruby​​ script.rb --first_name = donald --last_name = knuth

Produces:

生产：

$ donald knuth

$ donald knuth

#4

I personnaly use Docopt. This is much more clear, maintainable and esay-reading.

我个人使用Docopt。这更清晰，更易于维护和阅读。

Have a look to online Ruby implementation doc for examples. Usage is really straightforward.

有关示例，请查看在线Ruby实现文档。用法非常简单。

gem install docopt

Ruby code:

Ruby代码：

doc = <<DOCOPT
My program who says hello

Usage:
  #{__FILE__} --first_name=<first_name> --last_name=<last_name>
DOCOPT

begin
  args = Docopt::docopt(doc)
rescue Docopt::Exit => e
  puts e.message
  exit
end

print "Hello #{args['--first_name']} #{args['--last_name']}"

Then calling:

然后打电话：

$ ./says_hello.rb --first_name=Homer --last_name=Simpsons
Hello Homer Simpsons

And without arguments :

没有争论：

$ ./says_hello.rb
Usage:
  says_hello.rb --first_name=<first_name> --last_name=<last_name>