Ruby FAQ: How do I read command line arguments in a Ruby script (Ruby command line args)?
To read command line args in a Ruby script, use the special Ruby array ARGV to get the information you need. Here are a few examples.
To get the number of command line arguments passed in to your Ruby script, check ARGV.length, like this:
# quit unless our script gets two command line arguments unless ARGV.length == 2 puts "Dude, not the right number of arguments." puts "Usage: ruby MyScript.rb InputFile.csv SortedOutputFile.csv\n" exit end
In the case of this script, I am expecting two command line arguments, and if I don't get two args, I
exit the script.
To work with the actual values of the arguments that are passed into your Ruby program, just treat ARGV as a normal Ruby array, and get the values like this:
# our input file should be the first command line arg input_file = ARGV # our output file should be the second command line arg output_file = ARGV
For other tutorials on reading command line arguments from different programming languages, we have the following tutorials on our website: