@echo off
set src=%1
if %src%#==# set src=a.txt
if not exist %src% goto _err
type %src% | find /i "x=" > tmp.txt
for /f "tokens=2,4,6 delims= " %%i in (tmp.txt) do echo %%i %%j %%k >>b.txt
if exist tmp.txt del /f /q tmp.txt
if exist b.txt type b.txt
goto _quit
:_err
echo Error: I cannot find %src%.
echo Usage: %0
pause:_quit
set src=
set src=%1
if %src%#==# set src=a.txt
if not exist %src% goto _err
type %src% | find /i "x=" > tmp.txt
for /f "tokens=2,4,6 delims= " %%i in (tmp.txt) do echo %%i %%j %%k >>b.txt
if exist tmp.txt del /f /q tmp.txt
if exist b.txt type b.txt
goto _quit
:_err
echo Error: I cannot find %src%.
echo Usage: %0
pause:_quit
set src=