Finds proxy for the given url from pac file.

proxy_from_pac.js

var debug = false;

start();

function start()
{
  if (typeof $ARG === "undefined" || $ARG.length !== 2)
  {
    log("Usage: jjs -scripting proxy_from_pac.js -- <pacfile> <url>");
    return;
  }

  var proxy = findProxy($ARG[0], $ARG[1]);
  print("\nProxy: " + proxy);
}

function findProxy(pacFilePath, url)
{
  load(pacFilePath);
  var startIndex = url.indexOf(":") + 1;
  for (var ob = {"/": true, w: true, ".": true}; ob[url.charAt(startIndex)]; startIndex++);
  var endIndex = url.indexOf("/", startIndex + 1);
  endIndex = endIndex === -1 ? url.length() : endIndex;
  var host = url.substring(startIndex, endIndex);
  log("url: " + url + ", deduced host: " + host);
  return FindProxyForURL(url, host);
}

function shExpMatch(host, shellExpression /* e.g. *.local */)
{
  var regExByShell = 
    {
      ".": "\\.",
      "?": ".",
      "*": ".*"
    };
  var regExStr = "^" + shellExpression.replace(/./g, function(character) { return regExByShell[character] || character; }) + "$";
  var matched = new RegExp(regExStr).test(host);
  log("shExpMatch() shellExpression: " + shellExpression + ", modified regex: " + regExStr + ", host: " + host + ", matched: " + matched);
  return matched;
}

function _resolveHostNameToIp(hostOrIp)
{
  return java.net.InetAddress.getByName(hostOrIp).getHostAddress();
}

function isPlainHostName(host)
{
  var plainHostName = host.indexOf(".") == -1;
  log("isPlainHostName() host: " + host + ", plainHostName: " + plainHostName);
  return plainHostName;
}

function myIpAddress()
{
  var myIp = java.net.InetAddress.getLocalHost().getHostAddress();
  log("myIpAddress() myIp: " + myIp);
  return myIp;
}

function isInNet(hostOrIp, pattern, mask)
{
  var isInNetFlag = _isInNet(hostOrIp, pattern, mask);
  log("isInNet() hostOrIp: " + hostOrIp + ", pattern: " + pattern + ", mask: " + mask + ", isInNet: " + isInNetFlag);
  return isInNetFlag;
}

function _isInNet(hostOrIp, pattern, mask)
{
  log("_isInNet() hostOrIp: " + hostOrIp + ", pattern: " + pattern + ", mask: " + mask);
  var ip = _resolveHostNameToIp(hostOrIp);
  var ipArr = ip.split(".");
  var patternArr = pattern.split(".");
  var maskArr = mask.split(".");
  for (var i = 0; i < ipArr.length; i++)
  {
    log("_isInNet() ipArr: " + ipArr[i] + " & maskArr: " + maskArr[i] + " (" + (ipArr[i] & maskArr[i]) + ") !== " + patternArr[i]);
    if ((+ipArr[i] & +maskArr[i]) !== +patternArr[i])
      return false;
  }
  return true;
}

function isResolvable(host)
{
  log("isResolvable() host: " + host);
  var startTime = Date.now();
  // var resolvable = !(new java.net.InetSocketAddress(host, 80).isUnresolved()) // This waits for upto 14s if network is not reacheable;
  var resolvable = false;
  try { resolvable = java.net.InetAddress.getByName(host /* Can be ip also */).isReachable(4000); }
  catch(e) { /* Unresolvable */ }
  log("isResolvable() host: " + host + ", resolvable: " + resolvable + ", timeTaken: " + ((Date.now() - startTime)/1000).toFixed(2) + "s");
  return resolvable;
}

function dnsResolve(host)
{
  log("dnsResolve()");
  var startTime = Date.now();
  var ip = _resolveHostNameToIp(host);
  log("dnsResolve() host: " + host + ", ip: " + ip + ", timeTaken: " + ((Date.now() - startTime)/1000).toFixed(2) + "s");
  return ip;
}

function dnsDomainIs(host /* e.g. maps.google.com, www.google.com */, domain /* .google.com */)
{
  return host.endsWith(domain);
}

function localHostOrDomainIs(host, exactMatch)
{
  return host === exactMatch; // TODO: Need to check
}

// Returns number of dots(.) in hostname
function dnsDomainLevels(host)
{
  var noOfDots = 0;
  for (var i = -1; (i = host.indexOf(".", i + 1)) !== -1; noOfDots++);
  return noOfDots;
}

function weekdayRange(startDay /* MON */, endDay /* FRI */)
{
  var dayNames = ["SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT"];
  var todayNameIndex = (new Date()).getDay();
  var startDayIndex = dayNames.indexOf(startDay);
  var endDayIndex = dayNames.indexOf(endDay, startDayIndex);
  return (startDayIndex <= todayNameIndex) && (todayNameIndex <= endDayIndex);
}

function dateRange(startMonth, endMonth) // TODO: Should this not be monthRange ??????????
{
  var monthNames = ["JAN", "FEB", "MAR", "APR", "MAY", "JUN", "JUL", "AUG", "SEP", "OCT", "NOV", "DEC"];
  var thisMonthIndex = (new Date()).getMonth();
  var startMonthIndex = monthNames.indexOf(startMonth);
  var endMonthIndex = monthNames.indexOf(endMonth, startMonthIndex);
  return (startMonthIndex <= thisMonthIndex) && (thisMonthIndex <= endMonthIndex);
}

function timeRange(startHour, endHour)
{
  var thisHour = (new Date()).getHours();
  return (startHour <= thisHour) && (thisHour <= endHour); 
}

function log(msg)
{
  if (debug)
    print(msg);
}

Requires Java 8

Usage: jjs -scripting proxy_from_pac.js -- <pacfile> <url>