China DOS Union

I have a requirement: read the contents of a.txt three lines at a time, read one line from b.txt, then loop and write them into c.txt. How can this be done?

Assuming the line count ratio of files a and b is 3:1, and not considering special symbols:

@echo off

set p=-1

(for /f "delims=" %%i in (a.txt) do (

echo;%%i&set/a n+=1,m=n%%3

set/a test=1/m 2>nul||call :out

))>c.txt

exit



:out

set/a p+=1

if %p% equ 0 (for /f "delims=" %%j in (b.txt) do (echo;%%j&goto eof)) else (

for /f "skip=%p% delims=" %%j in (b.txt) do (echo;%%j&goto eof))

:eof

Thanks, it already meets the functional requirement