check wifi signal

Made this in response to treehouses/control#6

cli.js

@@ -77,6 +77,11 @@ var commands = [{
     command: 'wificountry <country>',
     description: 'changes the wifi country',
     action: './lib/wificountry.js'
+  },
+  {
+    command: 'checksignal',
+    description:"checks the RSSI of the RPi's wifi connection",
+    action: './lib/checksignal.js'
   }
 ]
 

lib/checksignal.js

@@ -0,0 +1,26 @@
+#!/usr/bin/env node
+
+var exec = require('child_process').exec;
+
+module.exports = () => {
+  var command = "iwconfig wlan0";
+
+  exec(command, (error, stdout, stderr) => {
+    if (error) {
+      console.log('There has been an error running this command: ' + error);
+    }
+    if (stderr) {
+      process.stdout.write(stderr)
+      process.exit(1)
+    }
+    var change = stdout.split("\n");
+    var SSID = change[0];
+    var index = SSID.indexOf("ESSID");
+    SSID = SSID.slice(index);
+
+    var signal = change[6];
+    index = signal.indexOf("Signal");
+    signal = signal.slice(index);
+    console.log(SSID + signal);
+  })
+}