批处理-将命令输出存储到变量（多行）

Question

I know a way of doing this which is a bit like cheating but the code below creates a temporary file and then deletes it. I don't want that happen. So is there a proper or better way of doing it?

command 2>> "temp"
set /p OUTPUT=<"temp"
del "temp"
echo %OUTPUT%

I know there is a solution which uses for loop but that doesn't work for commands which return more than one line of result. I want to store all of them into my variable. (I tried this code btw)

Answer 1

You can put it into a single variable with including linefeeds.

setlocal EnableDelayedExpansion
set LF=^


REM The two empty lines are required here
set "output="
for /F "delims=" %%f in ('dir /b') do (
    if defined output set "output=!output!!LF!"
    set "output=!output!%%f"
)
echo !output!

But it can be a bit tricky to handle the data later, because of the embedded linefeeds.
And there is still a limit of 8190 characters per variable.

Often it's easier to use an array.

setlocal EnableDelayedExpansion
set "output_cnt=0"
for /F "delims=" %%f in ('dir /b') do (
    set /a output_cnt+=1
    set "output[!output_cnt!]=%%f"
)
for /L %%n in (1 1 !output_cnt!) DO echo !output[%%n]!

Answer 2

looks a bit ugly:

for /f "delims=" %%i in ('dir notexistent.xxx  2^>^&1 1^>nul ') do echo %%i

in-depth-explanation here