add system.du

src/system.js

@@ -4,7 +4,8 @@ exports = module.exports = {
     getDisks,
     checkDiskSpace,
     getMemory,
-    getMemoryAllocation
+    getMemoryAllocation,
+    du
 };
 
 const apps = require('./apps.js'),
@@ -16,11 +17,22 @@ const apps = require('./apps.js'),
     docker = require('./docker.js'),
     notifications = require('./notifications.js'),
     os = require('os'),
+    path = require('path'),
     paths = require('./paths.js'),
     safe = require('safetydance'),
     settings = require('./settings.js'),
+    shell = require('./shell.js'),
     volumes = require('./volumes.js');
 
+const DU_CMD = path.join(__dirname, 'scripts/du.sh');
+
+async function du(file) {
+    const [error, stdoutResult] = await safe(shell.promises.sudo('system', [ DU_CMD, file ], {}));
+    if (error) throw new BoxError(BoxError.FS_ERROR, error);
+
+    return parseInt(stdoutResult.trim(), 10);
+}
+
 async function getVolumeDisks(appsDataDisk) {
     assert.strictEqual(typeof appsDataDisk, 'string');