improve ps

src/emulator/commands/ps.js

@@ -1,20 +1,24 @@
 const { Terminal } = require("xterm");
+const sleep = require('../../lib/sleep');
 
 /**
  * 
  * @param {string[]} argv 
  * @param {Terminal} terminal 
  */
-module.exports = (argv, terminal) => {
+module.exports = async (argv, terminal) => {
     if (argv.indexOf('--help') != -1) {
         terminal.write(
 `Usage: ${argv[0]} [OPTIONS]
 Show current process list`);
         return;
     }
-    terminal.write(
+    terminal.write('PID\tTTY\tTIME\t\tCMD');
-`\tPID\tTTY\tTIME\tCMD
+
- 42\tpts/0\t00:00:00\tzsh
+    await sleep(5);
- 43\tpts/0\t00:00:00\tps
+
+    terminal.write(`
+1\tpts/0\t00:00:00\tzsh
+2\tpts/0\t00:00:00\tps
 `);
 }

src/lib/sleep.js

@@ -0,0 +1 @@
+module.exports = (timeout) => new Promise(r => setTimeout(r, timeout));