in reply to Re^2: Invoking the Windows command line for selected directories
in thread Invoking the Windows command line for selected directories

Um. Off the top of my head, I don't know where it actually documented. It's one of those things that I picked up by osmosis through reading PM. Probably from tye. He's the source of most of the useful stuff regarding Perl and Win32 around here.

As for how it works, that's fairly easily explainable. It is a Win32-only special case coded into the sources. If the first argument to system is (exactly) '1', then the code adds the CREATE_NEW_PROCESS_GROUP flag to the creation flags parameter passed to CreateProcess(), which has the required effect of 'detaching' the process created from it's parent.

See also Re: How does system(1,"foo") work on Windows?.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.