Sys.getpid: Get the Process ID of the R Session
Description
Get the process ID of the R Session. It is guaranteed by the
operating system that two R sessions running simultaneously will
have different IDs, but it is possible that R sessions running at
different times will have the same ID.
Value
An integer, often between 1 and 32767 under Unix-alikes (but for
example FreeBSD and Mac OS >= 10.5 uses IDs up to 99999) and a
positive integer up to 32767) under Windows.