Errorlevel in a For loop (Windows batch)

Question

I have the following windows batch code:

for %%i in (iidbms iigcc iigcd dmfacp dmfrcp rmcmd qwerty) do (
  tasklist | findstr /i %%i
  echo %errorlevel%
  if %errorlevel% == 0 (echo %%i ok process found %errorlevel%)
  if %errorlevel% == 1 (echo %%i no process found %errorlevel%)
)

But it doesn't work as I expect.

All the name processes iidbms, iigcc, iigcd, dmfacp, dmfrcp, rmcmd are real, and they are found, instead qwerty is an invented one and should not find it, so should print " no process found 1", but it doesn't, it always prints 0.

But what I have noted is that if I run the tasklist | findstr /i qwerty from the dos prompt, just after there is that the %errorlevel% = 1.

What sort of answer could be or better is?

Answer 1

Add

setlocal EnableDelayedExpansion

to the start of your script, then use !errorlevel! instead of %errorlevel%

Delayed Expansion will cause variables to be expanded at execution time rather than at parse time

~ http://ss64.com/nt/delayedexpansion.html

The answer to another question that pointed me in the right direction:
Errorlevel of command executed by batch for loop

Answer 2

IF ERRORLEVEL returns TRUE if the return code was equal to or higher than the specified errorlevel. In your example, since 0 is lower than 1, the first errorlevel statement will always be true if the actual error code is 0 or above. What you want is to test for errorlevel 1 first.

E.g.:

for %%i in (iidbms iigcc iigcd dmfacp dmfrcp rmcmd qwerty) do (
    tasklist | findstr /i %%i
    if errorlevel 0 if not errorlevel 1 echo process
    if errorlevel 1 if not errorlevel 2 echo process not found
)

Another issue is if you want to echo the actual errorlevel from within the for loop. Since variables are resolved before the start of the loop, echoing %errorlevel% will always echo 0. If you want to echo the value at the execution time, you need to modify the snippet like so:

setlocal enabledelayedexpansion
for %%i in (iidbms iigcc iigcd dmfacp dmfrcp rmcmd qwerty) do (
    tasklist | findstr /i %%i
    if errorlevel 0 if not errorlevel 1 echo %%i ok process found !errorlevel!
    if errorlevel 1 if not errorlevel 2 echo %%i no process found !errorlevel!
)