Copy / paste user sid using command line?

Question

Is it possible to copy the user's SID from the registry (or something else) and paste into the txt file only using the command line (Windows 7)?

Answer 1

Via WMIC

wmic useraccount where name='%username%' get sid | findstr /b /C:"S-1" > file.txt

Via WHOAMI (duplicate percent signs, if used in a batch file)

for /F "tokens=2 delims=," %f in ('whoami /user /FO CSV /NH') do echo %~f > file.txt