| getpid {base} | R Documentation |
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.
Sys.getpid()
An integer, usually a small integer between 0 and 32767 under Unix-alikes and a much small integer under Windows.
Sys.getpid()