Command Line Arguments

Help & Support
1

I’m having some trouble finding documentation of implementing command-line arguments. I found something called option_parser, but did not find examples of it taking input from the user. I found other examples of taking user arguments with
ARGV, but they had no parameters. I tried inserting ARGV into an example I had with option_parser, but this and other attempts I made did not work:

 require "option_parser"
  
 string = "echo "
  
 OptionParser.parse do |parser|
    parser.banner = "Genric Banner"
  
    parser.on "-e", "--execute", "Execute commands" do
      ARGV
      exit
    end
    parser.on "-v", "--version", "Show version" do
      puts "version 1.0"
      exit
    end
    parser.on "-h", "--help", "Show help" do
      puts parser
      exit
    end
  end
  
  y = "#{string}#{ARGV}"
  
  Process.run(y, shell: true) do |proc|
    IO.copy(proc.output, STDOUT)
  end

I’m unsure of the best way to do this. If ARGV is needed, I’ll probably need to ask how to do with with multiple arguments. Any feedback appreciated.

2

Using the example from https://crystal-lang.org/api/master/OptionParser.html.

crystal build app.cr
./app -h
./app --upcase -t Jim
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3

Interesting, I was taken to a part of that same wiki earlier, but not the OptionParser section. I must have been googling something wrong. This I can work with. Thank you.

1 Like
4

np. I’d also check out https://crystal-lang.org/reference/getting_started/cli.html if you haven’t.

2 Likes
5

Also 2 goods shards for handling CLI:

Support sub-commands and other handy features

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