Ansi Tables on console

gistfile1.js

var ansi = require("ansi");
var cursor = ansi(process.stdout);

var colors = [
  "white", "black", "blue", "cyan", "green", "magenta", "red", "yellow", "grey", 
  "brightBlack", "brightRed", "brightGreen", "brightYellow", "brightBlue", "brightMagenta", "brightCyan", "brightWhite"
];
var styles = [ "bold", "italic", "underline", "inverse" ];

colors.forEach( function (color) {
  String.prototype[color] = function () {
    this._color = color;
    return this;
  };
});
styles.forEach( function (style) {
  String.prototype[style] = function () {
    if ( !this._styles ) this._styles = [];
    this._styles.push(style);
    return this;
  };
});

function printTable (table, opts) {  
  opts = opts || { align : [] };
  // compute row length
  if ( table.length === 0 ) return;
  var numCols = table.reduce(function (maxCols, col) {
    return ( col.length > maxCols ) ? col.length : maxCols;
  }, 0);
  var maxColumnLengths = Array(numCols);
  for ( var i = 0; i < numCols; i++ ) maxColumnLengths[i] = 0;
  table.map(function (row) {
    var i = 0;
    for ( ; i < numCols; i++ ) {
      if ( row[i] !== undefined && row[i].length > maxColumnLengths[i] ) {
        maxColumnLengths[i] = row[i].length;
      }
    }
  });

  // print table
  var output = [];
  table.forEach(function (row) {
    row.forEach(function (col, index) {
      if ( col._color ) {
        cursor[col._color]();
      }
      if ( col._styles ) {
        col._styles.forEach( function (style) {
          cursor[style]();
        });
      }
      process.stdout.write(padString(col.toString(), maxColumnLengths[index], opts.align[index]));
      process.stdout.write("  ");
      cursor.reset();
    });
    process.stdout.write("\n");
  });
}

function padString(str, padLen, align, padChar) {
  if ( str.length >= padLen ) return str;
  if ( padChar === undefined ) padChar = " ";
  switch ( align ) {
    case "center":
      var availableSlots = padLen - str.length;
      var right = Math.ceil(availableSlots / 2);
      var left = availableSlots - right;
      return Array(left+1).join(padChar) + str + Array(right+1).join(padChar);
    break;
    case "right":
      return Array(padLen + 1 - str.length).join(padChar) + str;
    break;
    default:
      return str + Array(padLen + 1 - str.length).join(padChar);
    break;
  }
}

var table = [
  [ "Package".blue().underline(), "Current".blue().underline(), "Wanted".blue().underline(), "Latest".blue().underline(), "Path".blue().underline() ],
  [ "fstream".red(), "0.1.24", "0.1.25".green(), "0.1.25".magenta(), "fstream".brightBlack() ],
  [ "lru-cache".yellow(), "2.3.1", "2.3.1".green(), "2.5.0".magenta(), "lru-cache".brightBlack() ],
  [ "node-gyp".red(), "0.11.0", "0.11.0".green(), "0.12.1".magenta(), "node-gyp".brightBlack() ],
  [ "npm-registry-client".red(), "0.2.29", "0.2.30".green(), "0.2.30".magenta(), "npm-registry-client".brightBlack() ]
];

printTable( table, { align : [ "left", "right", "right", "right", "left" ] } );