get() added function to get partial system info

lib/index.d.ts

@@ -681,3 +681,4 @@ export function vboxInfo(cb?: (data: Systeminformation.VboxInfoData[]) => any):
 export function getStaticData(cb?: (data: Systeminformation.StaticData) => any): Promise<Systeminformation.StaticData>;
 export function getDynamicData(srv?: string, iface?: string, cb?: (data: any) => any): Promise<any>;
 export function getAllData(srv?: string, iface?: string, cb?: (data: any) => any): Promise<any>;
+export function get(valuesObject: any, cb?: (data: any) => any): Promise<any>;

lib/index.js

@@ -308,6 +308,40 @@ function getAllData(srv, iface, callback) {
   });
 }
 
+function get(valueObject, callback) {
+  return new Promise((resolve) => {
+    process.nextTick(() => {
+      const allPromises = Object.keys(valueObject)
+        .filter(func => ({}.hasOwnProperty.call(exports, func)))
+        .map(func => exports[func]());
+
+      Promise.all(allPromises).then(data => {
+        const result = {};
+        let i = 0;
+        for (let key in valueObject) {
+          if ({}.hasOwnProperty.call(valueObject, key) && {}.hasOwnProperty.call(exports, key) && data.length >= i) {
+            if (valueObject[key] === '*' || valueObject[key] === 'all') {
+              result[key] = data[i];
+            } else {
+              const keys = valueObject[key].replace(/,/g, ' ').replace(/ +/g, ' ').split(' ');
+              const partialRes = {};
+              keys.forEach(k => {
+                if ({}.hasOwnProperty.call(data[i], k)) {
+                  partialRes[k] = data[i][k];
+                }
+              });
+              result[key] = partialRes;
+            }
+            i++;
+          }
+        }
+        if (callback) { callback(result); }
+        resolve(result);
+      });
+    });
+  });
+}
+
 // ----------------------------------------------------------------------------------
 // export all libs
 // ----------------------------------------------------------------------------------
@@ -374,3 +408,5 @@ exports.vboxInfo = vbox.vboxInfo;
 exports.getStaticData = getStaticData;
 exports.getDynamicData = getDynamicData;
 exports.getAllData = getAllData;
+exports.get = get;
+