Windows Batch For Loop: having trouble with the following code - for-loop

Question

set checker=0
for %%a in (%namelist%) do (
:startLoop
findstr "completed" %%a_Logs.txt
IF ERRORLEVEL 1 (
IF %checker%==120 (
set checker=0
goto endLoop
)
set /a checker=%checker%+1
#ping 127.0.0.1 -n 1 -w 1000 > nul
findstr "ERROR" %%a_Logs.txt
IF ERRORLEVEL 1 (
echo Waiting 1 second before rechecking (Max 2 mins)
echo time elapsed %checker% seconds
echo.
goto startLoop
)
findstr "ERROR" %%a_Logs.txt
IF NOT ERRORLEVEL 1 (
echo ERROR: %%a Error found
goto endLoop
)
)
findstr "completed" %%a_Logs.txt
IF NOT ERRORLEVEL 1 (
echo %%a completed
)
:endLoop
)
The above piece of code is to do the following:
Parse the variable namelist(where the contents are separated by spaces)
Check if "completed" is present in the %%a_Logs.txt file
If it is present, then iteration over, If it is not, then check for the string "ERROR" in same file
If ERROR is present, then output ERROR MSG and end iteration
If ERROR is not found, keep rechecking for the next 120 seconds before ending iteration
I keep getting the following output
FINDSTR: Cannot open %a_Logs.txt

Answer 1

You are attempting to GOTO a label within a FOR loop - that simply doesn't work. The moment a FOR loop executes GOTO, the loop is terminated, and the FOR context is lost. So your %%a FOR variable is no longer defined. A similar issue happens with IF statements, as described at (Windows batch) Goto within if block behaves very strangely.
You also have a problem when you attempt to expand %checker% within the same parenthesized code block that sets the value. That expansion occurs at parse time, and the entire block is parsed at once. So the value you see will always be the value that existed before the block was entered. The solution is to enable delayed expansion and use !checker! instead of %checker%.
Personally, I would probably make significant changes to your code. But I believe the following minimal changes can make your code work, assuming there are no other bugs:
enable delayed expansion
Move your DO loop code to a routine outside of the loop, and then have the loop CALL that routine with %%a as a parameter. CALL does not break the loop.
Substitute %1 for %%a in the routine
Substitute exit /b for goto endLoop. Also put exit /b at end of the routine
Make sure the code does not fall into the routine when the FOR loop finishes. I used a GOTO after the FOR loop
Substitute !checker! for %checker%
EDIT -The ) in the ECHO statement must be escaped
Here is the modified code (untested)
setlocal enableDelayedExpansion
set checker=0
for %%a in (%namelist%) do call :startLoop %%a
goto continue
:startLoop
findstr "completed" %1_Logs.txt
IF ERRORLEVEL 1 (
IF !checker!==120 (
set checker=0
exit /b
)
set /a checker=checker+1
#ping 127.0.0.1 -n 1 -w 1000 > nul
findstr "ERROR" %1_Logs.txt
IF ERRORLEVEL 1 (
echo Waiting 1 second before rechecking (Max 2 mins^)
echo time elapsed !checker! seconds
echo.
goto startLoop
)
findstr "ERROR" %1_Logs.txt
IF NOT ERRORLEVEL 1 (
echo ERROR: %1 Error found
exit /b
)
)
findstr "completed" %1_Logs.txt
IF NOT ERRORLEVEL 1 (
echo %1 completed
)
exit /b
:continue

Answer 2

I think the labels inside your for loop are messing it up. I just tried it moving the contents of the loop into a separate "subroutine" and that gets rid of the error you mention.
Try this:
set checker=0
for %%a in (foo bar baz) do (
call :loop %%a
)
goto :eof
:loop
set basename=%1
:startLoop
findstr "completed" %basename%_Logs.txt
IF ERRORLEVEL 1 (
IF %checker%==120 (
set checker=0
goto endLoop
)
set /a checker=%checker%+1
#ping 127.0.0.1 -n 1 -w 1000 > nul
findstr "ERROR" %basename%_Logs.txt
IF ERRORLEVEL 1 (
echo Waiting 1 second before rechecking (Max 2 mins)
echo time elapsed %checker% seconds
echo.
goto startLoop
)
findstr "ERROR" %basename%_Logs.txt
IF NOT ERRORLEVEL 1 (
echo ERROR: %basename% Error found
goto endLoop
)
)
findstr "completed" %basename%_Logs.txt
IF NOT ERRORLEVEL 1 (
echo %basename% completed
)
:endLoop
goto :eof