Index[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] Ubuntu Linux, network configuration tool UDP (User Datagram Protocol) 2nd system logging, security and UHCI (Universal Host Controller Interface) UID (user ID) 2nd ulimit command 2nd umask command umount command 2nd 3rd 4th uncompress program unexpand command uninstall mode, rpm uniq command Universal Host Controller Interface (UHCI) Unix BSD versus SysV printing Unix98, ps command options unprivileged ports until command until loops UPD (User Datagram Protocol) listing UDP-based connections update-modules command update-rc.d command updatedb command 2nd upgrade mode, rpm upstream clients (INN) USB devices configuring 2nd 3rd classes of USB devices controllers hotplug topology USB drivers finding assigned device file usbview command Usenet newsgroups 2nd archives contributing to user access mode user accounts 2nd environment, tuning password file and review questions and exercises setting home directory shadow passwords user ID (UID) 2nd user prompt ($) user variables in shell scripts useradd command 2nd userdel command 2nd usermod command 2nd username USERNAME environment variable users classes of, in access modes crontabs file access FTP acccess monitoring 2nd notifying of system issues quota limits security, setting up /usr filesystem 2nd 3rd 4th /doc /local dirctory /man /sbin/sendmail /share/doc /share/man /src/linux-kernel-version contents subdirectories /usr partition guidelines for size of |