Added sample/snippet for stdin processing

snippets/pwdtest.js

@@ -0,0 +1,70 @@
+/*
+Copyright 2022 Intel Corporation
+@author Bryan Roe
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+
+//
+// This code sample/snippet illustrates how to hookup stdin, so that input can be read.
+// In this particular case, we are using stdin to read a password
+//
+
+
+console.log('Starting Test...');
+
+console.echo = false;       // This disables local echo to the console when keys are pressed
+console.canonical = false;  // This takes the console out of canonical mode, which means stdin will process each key press individually, instead of by line.
+
+
+// On first use of process.stdin, will cause the runtime to create a stream object, and hook it up so that it can be used to read from stdin, either by piping it, or by registering for events
+process.stdin.chars = '';   // This is where we will store the result
+process.stdin.on('data', function (c)
+{
+    switch(c[0])
+    {
+        case 127: // Linux Backspace
+        case 8:   // Windows Backspace
+            process.stdout.write('\r');
+            for (i = 0; i < this.chars.length; ++i)
+            {
+                process.stdout.write(' '); // Whenever BS is pressed, we need to clear the entire line, so we can redraw the '*' characters
+            }
+            process.stdout.write('\r');
+            if (this.chars.length > 0) { this.chars = this.chars.substring(0,this.chars.length-1); } // On BS press, we will remove the last character we saved
+            for (i = 0; i < this.chars.length; ++i)
+            {
+                process.stdout.write('*'); // Output a '*' to the console for each character that we have saved
+            }
+            break;
+        case 10: // Linux CR
+        case 13: // Windows CR
+            console.log('\nPWD=' + this.chars); // When CR is pressed, we are done, and will simply dump what we saved to show what we captured
+            process.exit();
+            break;
+        default:
+            this.chars += c.toString();
+            process.stdout.write('*');  // For each key press, we will output a '*' to the console
+            break;
+    }
+});
+
+process.on('exit', function ()
+{
+    // On POSIX, it is very important that we reset the console back to its normal/default settings... Otherwise, 
+    // if we exit the app while the console is still set with echo and canonical disabled, it will remain in that state
+    // making it difficult for the user to know whats going on when trying to interact with the console.
+    console.echo = true;
+    console.canonical = true;
+});