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npm i --save steam-binary-vdf

Steam Binary VDF

steam-binary-vdf is a module for reading and writing the binary vdf file format used in files like shortcuts.vdf. This module also provides a utility function for calculating the steam://rungameid/ url for a shortcut.

Exports

readVdf(buffer: Buffer, offset?: number): Object

Reads a vdf file from a buffer and returns an object with its contents. This returns a "plain" object of [key: string]: value with the values from the vdf file.

writeVdf(map: Object): Buffer

Writes an object to a new buffer then returns the buffer.

VDF files values only accept:

• unsigned 32-bit numbers: writeVdf will error if a number is outside of the range 0 <= value <= 4294967295.
• strings without null chars \0: writeVdf will error if a string contains null chars. Remove, replace, or truncate your strings first. VDF files use null-terminated strings internally.
• Objects with string keys and accepted values: writeVdf will error if a value does not match an accepted type.

getShortcutHash(input: string): string

Returns the "hash" used by steam to represent non-steam shortcuts in the steam://rungameid/ format. This uses code adapted from Scott Rice's ICE program.

getShortcutUrl(appName: string, exe: string): string

Returns the shortcut url for a shortcut with the given name and target. The name is the AppName field and the target is the exe field from the shortcut entry in the shortcuts file.

This just returns "steam://rungameid/" + getShortcutHash(exe + appName)

Shortcuts.vdf example

import { readVdf, writeVdf } from "steam-binary-vdf";
import fs from "fs-extra";

// read the vdf
const inBuffer = await fs.readFile("C:\\Program Files (x86)\\Steam\\userdata\\USER_ID\\config\\shortcuts.vdf")

const shortcuts = readVdf(inBuffer);
console.log(shortcuts); // output below;

// add to the vdf
shortcuts.shortcuts['2'] = {
  AppName: 'Game 3',
  exe: 'D:\\Games\\Game.exe'
};

const outBuffer = writeVdf(shortcuts);

await fs.writeFile("C:\\Program Files (x86)\\Steam\\userdata\\USER_ID\\config\\shortcuts.vdf", outBuffer);

This will produce something like...

{
  shortcuts: {
    '0': {
      AppName: 'Game 1',
      exe: '"C:\\Program Files\\Game 1\\Game.exe"',
      StartDir: '"C:\\Program Files\\Game 1"',
      icon: '',
      ShortcutPath: '',
      LaunchOptions: '',
      IsHidden: 0,
      AllowDesktopConfig: 1,
      AllowOverlay: 1,
      openvr: 0,
      Devkit: 0,
      DevkitGameID: '',
      LastPlayTime: 1527542942,
      tags: {'0': 'some tag', '1': 'another tag'}
    },
    '1': {
      AppName: 'Another Game',
      exe: '"C:\\Program Files\\Some Game 2\\AnyExe.exe"',
      StartDir: '"C:\\Any Location"',
      icon: '',
      ShortcutPath: '',
      LaunchOptions: '',
      IsHidden: 0,
      AllowDesktopConfig: 1,
      AllowOverlay: 1,
      openvr: 0,
      Devkit: 0,
      DevkitGameID: '',
      LastPlayTime: 1525830068,
      tags: {}
    }
  }
}

Notable things about shortcuts.vdf:

• The root of VDF files are maps of string keys to values. shortcuts.vdf puts all of the shortcuts in the shortcuts value under the root. The vdf file can include more values under the root but typically does not. You can set and save other values under the root and Steam will treat the file like normal after a restart, but won't necessarily keep the extra data.
• shortcuts is a map with numbers as string keys. Using a proper key here doesn't actually matter: steam will fix all keys to a number-as-a-string on startup.
• tags is map-as-a-list like shortcuts, but I couldn't get steam to use it so I couldn't test its behavior.
• When steam starts, it reads and sanitizes shortcuts.vdf. This means:
  • Any non-object values under shortcuts get discarded
  • Any object values under shortcuts get converted into shortcut definitions. Unknown keys in the object are removed and any non-existent shortcut definition keys are added with their default values.
  • Keys under shortcuts get converted to numbers-as-strings. For example, setting shortcuts.a = {AppName: 'Test'} in the above example would become shortcuts['2'] or ['3'] depending on the contents.
• LastPlayTime is a timestamp
• Booleans are represented as numbers where 0 is false and 1 is true.
• If shortcuts.vdf does not follow the binary vdf format, it is cleared and reset to an empty shortcuts vdf.

The default values for a shortcut definition are:

{
  AppName: '',
  exe: '',
  StartDir: '',
  icon: '',
  ShortcutPath: '',
  LaunchOptions: '',
  IsHidden: 0,
  AllowDesktopConfig: 1,
  AllowOverlay: 1,
  openvr: 0,
  Devkit: 0,
  DevkitGameID: '',
  LastPlayTime: 0,
  tags: {}
}

Binary VDF Format

The binary vdf format is built around a few structures:

• Null-terminated strings (here on called String)
• 32-bit little-endian integers (here on called Integer)
• Map (here on called Map)
• 1-byte object type (here on called MapItemType)
  • 0x00 represents a Map
  • 0x01 represents a String
  • 0x02 represents a Number
  • 0x08 represents the end of a map

Map is structured as reptitions of any of the following:

• MapItemType(0x01) String(name) String(value)
• MapItemType(0x02) String(name) Integer(value)
• MapItemType(0x00) String(name) Map(value)
• MapItemType(0x08)

When a type of 0x08 is encountered, map reading stops.

The root of a binary vdf file is a Map.

steam-binary-vdf reads Integers as unsigned integers. I haven't seen enough user-editable integers in vdf files to test if this is a correct representation of the data.

steam-binary-vdf reads Strings as utf-8. The vdf format likely accepts any sequence of bytes for a string as long as it doesn't contain a null character \0.