One that runs when the user login
One that authenticate the user while logging in
One that user that belong to the same group
belong to the same group One that give no permission
IBM-compatible
Alpha
Macintosh
SPARC
Uname-r
Uname-n
Uname-t
Kernal
Windows
Linux
Mac
Dos
TCP port number 21
TCP port number 22
TCP port number 23
TCP port number 24