Store output of Windows command in batch file

Provided a simple batch file test.cmd with the contents:

echo jscott

You can set the output into a variable with the following command line:

FOR /F "tokens=*" %a in ('test.cmd') do SET OUTPUT=%a

Used on the command line like this:

Environment variable OUTPUT not defined
C:\>FOR /F "tokens=*" %a in ('test.cmd') do SET OUTPUT=%a

Should you want to use the FOR within a batch file, rather than command line, you need to change %a to %%a.

This is how I do this:

vol c: > result.txt
set /p DATA=<result.txt
echo %DATA%
del result.txt

If result.txt has more than 1 line, only the top line of the file is used for %DATA%. You could also make result.txt into a variable itself, such as %OUTPUT%.