Extract line below Findstr criteria in Batch file for cycle - variables

Question

I'm trying to extract from a set of txt files the line
placed 2 rows below the one matching search criteria
and redirect output to a csv file.
I managed to do that for a specific txt file in the set,
but I'm getting troubles in writing the For Cycle
to batch-scan each txt in a given folder.
Through this, I wrote the following code to scan
a specific file. It works fine:
setlocal EnableDelayedExpansion
cd "myFolder"
if exist myOutput.csv del myOutput.csv
for /F "delims=:" %%A in ('findstr /B /N /C:"myCriteria" "myFile.txt"') do (
set /A LineBelow=%%A+2
set "LineBelow=!LineBelow!: "
)
(for /F "tokens=1* delims=:" %%A in ('findstr /N "^" "myFile.txt" ^| findstr /B "%LineBelow%"') do ^
echo %%B>>myOutput.csv)
start myOutput.csv
ENDLOCAL
When I tried to generalize the code in a For Cycle to scan each txt in myFolder
I got an error in Findstr: !LineBelow! happens to be an empty variable...
Here's the flawed For Cycle:
setlocal EnableDelayedExpansion
cd "myFolder"
if exist myOutput.csv del myOutput.csv
for %%F IN ("*.txt") do (
(
for /F "delims=:" %%A in ('findstr /B /N /C:"myCriteria" "%%F"') do (
set /A LineBelow=%%A+2
set "LineBelow=!LineBelow!: "
))
(for /F "tokens=1* delims=:" %%A in ('findstr /N "^" "%%F" ^| findstr /B "!LineBelow!"') do ^
echo %%B>>myOutput.csv))
start myOutput.csv
ENDLOCAL
Could anybody help me in correcting this code?
Thanks

Answer 1

#echo off
setlocal enableextensions enabledelayedexpansion
cd "myFolder"
> myOutput.csv (
for /f "tokens=1,2 delims=:" %%a in ('
findstr /b /n /c:"myCriteria" *.txt
') do (
set /a "line=%%b+2"
for /f "tokens=1,* delims=:" %%c in ('
findstr /n "^" "%%a" ^| findstr /b /c:"!line!:" 2^>nul
') do echo(%%d
)
)
This uses findstr to directly enumerate all the lines matching the myCriteria and include in the output the name of the file (%%a) and the number of the line (%%b). This information is used to retrieve the final line (%%d) from the matching files.