var exec = require ('child_process') .exec;

console.log ('Checking vnStat requirement...');

exec ('vnstat --version', function (err, res, stderr) {
  if (err) { throw err; }
  res.replace (/^vnStat (\d+)\.(\d+) /, function (s, major, minor) {
    if (major >= 1 && minor >= 13) {
      console.log ('vnStat correct');
    } else {
      console.log ('Wrong vnStat version: requires >= v1.13, but v'+ major +'.'+ minor +' installed');
      process.exit (1);
    }
  });
});
@@ -155,16 +155,20 @@
  (err) %7B
+%0A   
  throw e
@@ -170,19 +170,22 @@
 row err;
+%0A 
  %7D%0A
+%0A
   res.re
@@ -328,19 +328,25 @@
     
-%7D else %7B%0A  
+  return;%0A    %7D%0A%0A
     
@@ -406,16 +406,17 @@
 , but v'
+ 
 + major 
@@ -420,11 +420,13 @@
 or +
+ 
 '.'
+ 
 + mi
@@ -430,16 +430,17 @@
  minor +
+ 
 ' instal
@@ -450,18 +450,16 @@
 ');%0A    
- 
- 
 process.
@@ -468,22 +468,16 @@
 it (1);%0A
-    %7D%0A
   %7D);%0A%7D)
@@ -477,8 +477,9 @@
  %7D);%0A%7D);
+%0A

Clean up preinstall.js