A character vector with fields
sysnameThe operating system name.
releaseThe OS release.
versionThe OS version.
nodenameA name by which the machine is known on the network (if
any).
machineA concise description of the hardware, often the CPU type.
loginThe user's login name, or "unknown"
if it cannot be
ascertained.
userThe name of the real user ID, or "unknown"
if it
cannot be ascertained.
effective_userThe name of the effective user ID, or
"unknown"
if it
cannot be ascertained. This may differ from the real user in
‘set-user-ID’ processes.
The first five fields come from the uname(2) system call. The
login name comes from getlogin(2), and the user names from
getpwuid(getuid()) and getpwuid(geteuid())
The last three fields give the same value on Windows.