fs.ReadStream だけを使う方法が Stack Overflow にあるけど、readline で簡単にできた。ライブラリを使うなら byline を使うとよさそう。 var fs = require('fs'), readline = require('readline'), rs = fs.ReadStream('readline.js'), rl = readline.createInterface({'input': rs, 'output': {}}); var i = 0; rl.on('line', function (line) { console.log(i++ + ': ' + line.trim()); }); rl.resume(); % node readline.js 0: var fs = require('fs'), 1: readline = r