add os code

Author: wangding

04-process/01-information.js

@@ -26,3 +26,10 @@ console.log('\nApp config:');
 log(process.config);
 
 process.report.writeReport();
+
+const os = require('os');
+log(os.cpus());
+log(`linux uptime: ${os.uptime()} s`);
+log(os.version());
+log(os.networkInterfaces());
+log(os.userInfo());

04-process/05-signal.js

@@ -14,3 +14,7 @@ process.on('SIGINT', () => {
 process.on('SIGTSTP', () => {
   log('You have pressed Ctrl + Z.');
 });
+
+const os = require('os');
+
+console.log(os.constants.signals);