vdfplus is a small library that aims to help with converting Valve's KeyValue format to JSON and vice versa. vdfplus is special in that it "arrayifies" key-tokens that appear multiple times in the .vdf, e.g. Steam Controller configurations. Per default tt also tries to casts values-tokens into their respective data type.
vdfplus can be used with nodejs, in the browser or via command-line.

npm install vdfplus

npm install vdfplus -g

VDF exposes two functions parse and stringify. They are derived from the JSON.parse and JSON.stringify.

Parses a VDF string into a JavaScript object

Stringifies an object to VDF.

const vdfplus = require("vdfplus")
// or ES6
import vdfplus from "vdfplus"

<script src="node_modules/vdfplus/lib/vdfplus.web.js"></script>
<!-- OR minified-->
<script src="node_modules/vdfplus/lib/vdfplus.web.min.js"></script>

vdfplus is using UMD for exports It supports most common module loaders in the browser or simply adds a global namespace VDF if no loader is present.

• Read file or get the text from a textarea
• Parse the VDF into an object
• Modify object
• Stringify object
• Save to file or fill textarea with JSON string

// It is important to use the proper encoding
let vdfRaw = readFileSync("test/testfiles/test.vdf", "utf8")
// or read from textarea
let vdfRaw = document.getElementById("vdf-text").value

// Parse VDF string
let vdf = VDF.parse(vdfRaw)

// Change data
vdf["a-new-root-key"] = {
    "foo": "bar",
    "baz": [
        1, 2, 3, 4, 5
    ]
}

// Stringify the changes to vdf, indent using tabs and separate pairs with two spaces
let str = VDF.stringify(vdf, "\t", "  ")

// Save file
writeFileSync("test/testfiles/test.vdf", "utf8")
// or write to textarea
document.getElementById("json-text").value = str

vdfplus can also be used via command-line. Per default vdfplus parses VDF to JSON, so adding -j or --json s not needed! Data can be piped in via stdin and will be piped out to stdout if no uutput file was specified.
indentation is used for VDF and for JSON (defaults to 2 spaces [" "]), separate only relevant for VDF (defaults to tabs [\t]). Per default vdfplus will try to cast value-tokens into their respective data types. encoding and output-encoding are only for files

Usage: vdfplus [options] <input> <output>

Options:
    -V, --version                       output the version number
    -j, --json                          VDF to JSON (default behavior)
    -v, --vdf                           JSON to VDF
    -d, --indentation <char or number>  indentation for the VDF/JSON. number or whitespace characters. defaults to 2 spaces
    -s, --separator <char>              space between VDF key-value pairs. defaults to '\t'
    -e, --encoding <encoding>           encoding of input. defaults to 'utf8'
    -o, --output-encoding <encoding>    encoding of the output. defaults to 'utf8'
    -n, --no-types                       disable JSON types. all values will be strings
    -h, --help                          output usage information

Simple VDF to JSON conversion:

$ vdfplus input.vdf output.vdf

Simple JSON to VDF conversion:

$ vdfplus -v input.vdf output.vdf

Piping:

# stdin, file out
$ echo "foo" { "bar" "baz" } | vdfplus - result.json

# stdin, stdout
$ echo "foo" { "bar" "baz" } | vdfplus -
# outputs:
# {
#   "foo":  {
#     "bar":    "baz"
#   }
# }

# file in, stdout
vdfplus result.json -v

Formatting

# create vdf, indent with tabs and use two spaces between pairs
vdfplus -v -i \t -s 2 input.json output.vdf

• Unquoted keys and values are not supported
• Comments will be lost when converting from and to VDF