filter log file with nodejs for fun

gistfile1.js

#!/usr/bin/env node

var fs = require('fs')
  , input = 'worklog.in'
  , output = 'worklog.out';


var spliters = {
    block: 'Revision'
  , field: [
        { name: 'date', head: 'Date: ',   tail: '\n'    }
      , { name: 'msg',  head: 'Message:', tail: '----' }
    ] 
}


function readAndWrite(input, output, process) {
  fs.readFile(input, 'utf-8', function(err, content) {
    if (err) throw err;  
    fs.writeFile(output, process(content), function(err){
      if (err) throw err;
      else console.log('done.');
    });
  })
}


readAndWrite(input, output, function(content) {
  return content
    .split(spliters.block)
    .map(function(block) {
      return spliters.field.map(function(spliter) {
        var temp = block.split(spliter.head);
        return temp.length 
          && (temp = temp[1]) 
          && (temp = temp.split(spliter.tail)[0])
          && temp.replace(/\n+/g, ' ')
          || '';
      }).join('');
    }).reverse().join('\n');  
});