title: why does my batch script says "missing operator"?
body: <p>I'm using this script:</p>
  
  <pre><code>@echo on
  setlocal ENABLEDELAYEDEXPANSION
  set vidx=0
  for /F "tokens=*" %%A in (C:\Users\Diana\Desktop\names.txt) do (
      SET /A vidx=!vidx! + 1
      snmpwalk -v 2c -c root %%A .1.3.6.1.2.1.25.3.3.1.2 &gt; C:\Users\Diana\Desktop\cpu.txt
      snmpwalk -v 2c -c root %%A .1.3.6.1.2.1.25.5.1.1.2 &gt; C:\Users\Diana\Desktop\ramvid.txt
      snmpwalk -v 2c -c root %%A .1.3.6.1.2.1.25.2.2 &gt; C:\Users\Diana\Desktop\ram.txt
  )
  
  FOR /F "tokens=4" %%B IN (C:\Users\Diana\Desktop\ram.txt) DO echo %%B &gt;&gt; C:\Users\Diana\Desktop\ramfiltruotas.txt
  FOR /F "tokens=4" %%B IN (C:\Users\Diana\Desktop\cpu.txt) DO echo %%B &gt;&gt; C:\Users\Diana\Desktop\cpufiltruotas.txt
  FOR /F "tokens=4" %%B IN (C:\Users\Diana\Desktop\ramvid.txt) DO echo %%B &gt;&gt; C:\Users\Diana\Desktop\ramvidfiltruotas.txt
  
  for /F %%a in (C:\Users\Diana\Desktop\ramvidfiltruotas.txt) do set /a c+=%%a echo %c% &gt;&gt; C:\Users\Diana\Desktop\naujas.txt
  </code></pre>
  
  <p>I am trying to calculate the sum of numbers that are in file <code>ramvidfiltruotas.txt</code>, but when I start the script it shows me a lot of this: </p>
  
  <pre><code>C:\Users\Diana&gt;set /a c+=3472 echo   1&gt;&gt;C:\Users\Diana\Desktop\naujas.txt
  Missing operator.
  
  C:\Users\Diana&gt;set /a c+=2616 echo   1&gt;&gt;C:\Users\Diana\Desktop\naujas.txt
  Missing operator.
  </code></pre>
  
  <p>Maybe someone could help me to find the problem here?</p>
  
  <p>By the way, this script works on other computer.</p>