実行中のプロセスIDを取得するJScript

getProcessID.js

/**
 * JSON polyfill
 * https://www.bugbugnow.net/2018/05/wshjscriptjson.html
 */
var global = Function('return this')();
if (!global.JSON) {
    global.JSON = {
        parse: function (sJSON) { return eval('(' + sJSON + ')'); },
        stringify: (function () {
            var toString = Object.prototype.toString;
            var hasOwnProperty = Object.prototype.hasOwnProperty;
            var isArray = Array.isArray || function (a) { return toString.call(a) === '[object Array]'; };
            var escMap = { '"': '\\"', '\\': '\\\\', '\b': '\\b', '\f': '\\f', '\n': '\\n', '\r': '\\r', '\t': '\\t' };
            var escFunc = function (m) { return escMap[m] || '\\u' + (m.charCodeAt(0) + 0x10000).toString(16).substr(1); };
            var escRE = /[\\"\u0000-\u001F\u2028\u2029]/g;
            return function stringify(value) {
                if (value == null) {
                    return 'null';
                } else if (typeof value === 'number') {
                    return isFinite(value) ? value.toString() : 'null';
                } else if (typeof value === 'boolean') {
                    return value.toString();
                } else if (typeof value === 'object') {
                    if (typeof value.toJSON === 'function') {
                        return stringify(value.toJSON());
                    } else if (isArray(value)) {
                        var res = '[';
                        for (var i = 0; i < value.length; i++)
                            res += (i ? ', ' : '') + stringify(value[i]);
                        return res + ']';
                    } else if (toString.call(value) === '[object Object]') {
                        var tmp = [];
                        for (var k in value) {
                            // in case "hasOwnProperty" has been shadowed
                            if (hasOwnProperty.call(value, k))
                                tmp.push(stringify(k) + ': ' + stringify(value[k]));
                        }
                        return '{' + tmp.join(', ') + '}';
                    }
                }
                return '"' + value.toString().replace(escRE, escFunc) + '"';
            };
        })()
    };
}

Enumerator.prototype.toArray = function () { var r = []; var e = this; for (e.moveFirst(); !e.atEnd(); e.moveNext()) { var i = e.item(); r.push(i); } return r; }

var SWbemPropertySet = function (collection) {
    var ret = {};
    var array = new Enumerator(collection).toArray();
    for (var i = 0; i < array.length; i++) {
        var value = null
        var property = array[i];

        if (property.Value != null) {
            if (property.IsArray) {
                value = new VBArray(property.Value).toArray();
            } else {
                value = property.Value;
            }
        }

        ret[property.Name] = value;
    }
    return ret;
};

var SWbemObjectSet = function (collection) {
    var ret = [];
    var array = new Enumerator(collection).toArray();
    for (var i = 0; i < array.length; i++) {
        ret.push(SWbemPropertySet(array[i].Properties_));
    }
    return ret;
};

function getChildProcessProperties(childProcess) {
    var childProcessID = childProcess.ProcessID;
    if (typeof childProcessID != 'number') {
        throw new Error('The ProcessID of the child is not a number: ' + childProcessID);
    }

    var filtered = SWbemObjectSet(GetObject('winmgmts:root\\CIMV2').ExecQuery('SELECT * FROM Win32_Process WHERE ProcessID=' + childProcessID));
    if (filtered.length != 1) {
        throw new Error('The child process cannot be identified from the ProcessID: ' + filtered.length);
    }
    // WScript.Echo(JSON.stringify(filtered))

    return filtered.pop();
}

function getProcessID() {
    var catched = false;
    var rawProcessID;
    var childProcess = new ActiveXObject('WScript.Shell').Exec('mshta -');
    try {
        rawProcessID = getChildProcessProperties(childProcess).ParentProcessId;
    } catch (e) {
        catched = true;

    } finally {
        try {
            childProcess.Terminate();
        } catch (e) { }
    }
    if (catched) {
        return getProcessID();
    }

    var processID = parseInt(rawProcessID);
    if (isNaN(processID)) {
        throw new Error('The ProcessID is not a number: ' + rawProcessID);
    }

    return processID;
}

pid = getProcessID();
WScript.Echo(pid);