Question

I have two text files which contain the below numbers

File1
00000
11111

File2
00000
11111
22222

I need a code which compares the contents of file2 to that of file1 and the numbers which are not matched , in this case ‘22222’ be the only content in file2.

In short i want to erase the content of file2 and put the non matched content in file2. Below is the code i have tried but it just erases the entire thing in the file2.

setlocal enabledelayedexpansion

for /f "tokens=1" %%a in (file1) do (type file2 | findstr /v %%a > file2)

pause

Bottom line i need to achieve the below results

File1
00000
11111

File2
22222

Help please !

Answer 1

This does the job. It hinges around using findstr /m option and errorlevels.

Also it writes to a temporary file during processing (and cleans it).

@echo off
setlocal enabledelayedexpansion
echo Stripping duplicates in file2 (%2) compared to lines in file1 (%1)

if not exist "%1" (
  echo That first file doesn't exist.
  exit /b 1
)

if not exist "%2" (
  echo That second file doesn't exist.
  exit /b 2
)

REM Create empty temporary file
echo. 2> %2.tmp

for /f "tokens=1" %%a in (%2) do (
  echo Processing %%a
  >nul call findstr /m "%%a" %1
  if errorlevel 1 (
    echo OK
    >> %2.tmp echo %%a
  ) else (
    echo Duplicate!
  )
)


echo Writing results to %2
xcopy /y /q %2.tmp %2
del /q %2.tmp