cat

node

(cat.js)

#!/usr/bin/env node

const readline = require('readline');
const fs = require('fs');

for(var i=2; i<process.argv.length; i++){
  const rl = readline.createInterface({
    input: fs.createReadStream(process.argv[i]),
    output: process.stdout,
    terminal: false
  }).on('line', function (line) {
    console.log(line);
  });
}


実行結果

$ ./cat.js sample.txt sample.txt 
1
2
abc
1
2
abc

参照したURL:
https://nodejs.org/api/readline.html

ruby

#!/usr/bin/env ruby
while line = gets
  puts line
end

http://stackoverflow.com/questions/273262/best-practices-with-stdin-in-ruby

#!/usr/bin/env ruby

f=open(ARGV[0])
f.each do |line|
  puts line
end