Pacparser

A library to parse proxy auto-config (PAC) files in Node.js.

It run pac script in a Node.js vm and execute findProxy method.

Installation

npm install pacparser # use in node.js
npm install pacparser -g # use as a command line tool

Usage

You can create a new instance of Pacparser and load a PAC file like this:

import Pacparser from "pacparser";
const pacParser = new Pacparser();
pacParser.parsePac("https://proxy.example.com/proxy.pac");
const proxy = await pacParser.findProxy("https://direct.mozilla.org");

Or like this:

import Pacparser from "pacparser";
const pacParser = Pacparser.create(path.join(__dirname, "./proxy.pac"));
await pacParser.findProxy("https://direct.mozilla.org"); // returns "DIRECT"

You can input a pac source (filepath or url or pac script) by

new Pacparser(pac); // return a new instance
Pacparser.create(pac); // return a new instance , same as new Pacparser(pac)
pacParser.parsePac(path); // switch pac source by call parsePac() in pacParser instance

And then you can find proxy by call findProxy()

await pacParser.findProxy(url); // return a promise
await pacParser.findProxy("https://direct.mozilla.org"); // returns "DIRECT"

CLI

pacparser exec

You can use pacparser as a cli tool to parse pac file.

pacparser exec --pac './proxy.pac' --findproxy https://www.google.com # DIRECT
# Or use shortcut command
pap exec -p './proxy.pac' -f https://www.google.com # DIRECT

pap exec -p  'function FindProxyForURL(url, host) {
  if (
    (isPlainHostName(host) || dnsDomainIs(host, ".mozilla.org")) &&
    !localHostOrDomainIs(host, "www.mozilla.org") &&
    !localHostOrDomainIs(host, "merchant.mozilla.org") &&
    !localHostOrDomainIs(host, "www.google.com")
  ) {
    return "DIRECT";
  } else {
    return "PROXY w3proxy.mozilla.org:8080; DIRECT";
  }
}' -f https://www.google.com  # PROXY w3proxy.mozilla.org:8080; DIRECT

pap exec -p  http://localhost:3000/proxy.pac -f https://www.google.com  # DIRECT

pacparser builtin functions

pap builtin -f isPlainHostName -i www.google.com  # false
pap builtin -f isResolvable -i www.google.com  # true
pap builtin -f isInNet -i www.google.com,192.168.1.0,255.255.255.0 # false
pap builtin -f isInNet -i "192.168.1.1","192.168.1.0","255.255.255.0" # true
pap builtin -f myIpAddress  # 192.168.1.65

API

Pacparser

The main class.

static Pacparser.create(path?string)

Create a new instance of Pacparser.

pacparser.parsePac(pac:string): pacparser instance

switch pac source (filepath or url or pac script) by call parsePac() in pacParser instance, it return the pacparser instance, so you can chain call.

const pacParser = Pacparser.create();
pacParser.parsePac(path.join(__dirname, "./proxy.pac")).findProxy("https://direct.mozilla.org");

pacparser.findProxy(url) : Promise<string>

Find the proxy for a given URL.

pacparser.cleanup()

Cleanup the pacparser instance pac source

pacparser.getPacSource()

Get pac source in pacparser instance

pacparser.getPacCode()

Get pac code in pacparser instance

pacparser.reload()

If pac source is changed,it will reload pac source

Builtin functions

Pacparser provides some builtin functions to help you write your pac script. you can read more about them in Proxy Auto-Configuration (PAC) file

import {
  isPlainHostName,
  dnsDomainIs,
  localHostOrDomainIs,
  isResolvable,
  isInNet,
  dnsResolve,
  convert_addr,
  myIpAddress,
  shExpMatch,
  dnsDomainLevels,
  weekdayRange,
  dateRange,
  timeRange,
  alter,
} from "pacparser";

isPlainHostName("www.mozilla.org"); // false
isPlainHostName("www"); // true
dnsDomainIs("www.mozilla.org", ".mozilla.org") // true
localHostOrDomainIs("www.mozilla.org", "www.mozilla.org") // true (exact match)
isResolvable("www.mozilla.org") // true
dateRange(1, "JUN", 1995, 15, "AUG", 1995);
isInNet("192.168.1.1", "192.168.1.0", "255.255.255.0")
convert_addr("192.0.2.172"); // returns the decimal number 1745889538
dnsDomainLevels("www.mozilla.org"); // 2
...

License

MIT