http://www.perlmonks.org?node_id=913233


in reply to Re^3: exec vs. system
in thread exec vs. system

I never heard of system(1,...) being sensible syntax, so probably this is an extension in your windows perl dialect.
It would be sensible syntax if there were a command named "1" that ran its arguments on processor 1 in the background. I have to hope this is what's going on. Tampering with perl syntax would be too ugly to contemplate.