First iwlist draft handling ubuntu and raspberry pi outputs

lib/iwlist.js

@@ -1,3 +1,84 @@
 /**
+ * iwlist - a powerful tool with a horrible output
  * Created by kc on 04.04.16.
  */
+
+const _       = require('lodash');
+const tool    = '/usr/bin/iwlist';
+const cmdLine = tool + ' scan';
+
+const macRegex  = /([0-9a-zA-Z]{1}[0-9a-zA-Z]{1}[:]{1}){5}[0-9a-zA-Z]{1}[0-9a-zA-Z]{1}/;
+const cellRegex = /Cell [0-9]{2,} - Address:/;
+/**
+ * Parsing the output of iwlist, tool having a lot of different faces :-(
+ * @param str output of the tool
+ * @param callback
+ */
+function parseOutput(str, callback) {
+  var err   = null;
+  var wifis = [];
+
+  try {
+    var blocks = str.split(cellRegex);
+
+    blocks.forEach(block => {
+      var network = {};
+      var lines   = block.split('\n');
+      if (macRegex.exec(lines[0])) {
+        // First line is the mac address (always! (?))
+        network.mac = lines[0].trim();
+
+        lines.forEach(line => {
+          // SSID
+          if (line.indexOf('ESSID:') > 0) {
+            network.ssid = _.trim(line.split(':')[1], '"');
+          }
+
+          // Security
+          else if (_.startsWith(line.trim(), 'IE:')) {
+            network.security = line.split(':')[1].trim();
+          }
+
+          // Channel, an ugly thing to get it
+          else if (_.startsWith(line.trim(), 'Frequency:')) {
+            network.channel = parseInt(_.trim(line, ' )').split(/Channel/)[1], 10);
+          }
+            
+          // Another ugly thing, the signal which can have different formats, even worse als
+          // having different identifiers
+          else if (line.indexOf('Signal level') > -1) {
+            if (line.indexOf('Quality') > -1) {
+              // This is a "Quality=40/70  Signal level=-70 dBm" line
+              network.rssi = parseInt(line.substr(line.indexOf('Signal level') + 13), 10);
+            }
+            else {
+              // This is a "Signal level=60/100" line
+              var elements = line.split('=');
+              elements.forEach(e => {
+                if (e.indexOf('/') > 0) {
+                  // that's our part
+                  var parts    = e.split('/');
+                  var level    = Math.floor(100 * parseInt(parts[0], 10) / parseInt(parts[1], 10));
+                  network.rssi = level / 2 - 100;
+                }
+              })
+            }
+          }
+        });
+        wifis.push(network);
+      }
+    });
+  }
+  catch (ex) {
+    err = ex;
+  }
+
+  callback(err, wifis);
+}
+
+
+module.exports = {
+  parseOutput: parseOutput,
+  cmdLine    : cmdLine,
+  tool       : tool
+};