How can same program in ruby accept input from user as well as command line arguments

Question

My ruby script gets certain inputs from command line arguments. It check if any of the command line argument is missing, then it prompts for an input from user. But i am not able to get input from user using gets.

Sample code: test.rb

name=""
ARGV.each do|a|
    if a.include?('-n')
        name=a
        puts "Argument: #{a}"
    end
end
if name==""
    puts "enter name:"
    name=gets
    puts name
end

Running script: ruby test.rb raghav-k

Results in the error:

test.rb:6:in `gets': No such file or directory - raghav-k (Errno::ENOENT)
    from test.rb:6:in `gets'
    from test.rb:6:in `<main>'

Any pointers in this direction will be really grateful Thanks Sandy

Answer 1

gets will only read from the real $stdin (ie the user) if there are no command line arguments. Otherwise it'll take those arguments as files to concatenate as a virtual $stdin.

You can use STDIN.gets to make sure you're always using the right function.

You can also delete the arguments from ARGV as you go (or remove them all in one go), your gets should work correctly.