• Disk: df -h (freier/belegter Platz)
• Display resolution: xrandr -s <width in px>x<height in px> (may require restart of window manager, e.g. fvwm)
• HTTP Proxy: export http_proxy=http://<host>:<port>
• Keyboard layout: dpgk-reconfigure console-data (Konsole), setxkbmap -layout de -variant nodeadkeys (X), edit /etc/X11/xorg.conf (X)
• Locale: Set locale as non root user: edit ~/.bashrc. Add e.g. the following line: export LANG=de_DE.UTF-8 (German, UTF-8)
• Package: dpkg -L <package name> (Lists all installed files of a deb package)
• Users: List all currently logged in users: “users” or “who”
• Zeit und Datum stellen, zum Beispiel: date -s “1 SEP 2010 18:00:00”

• “?<string>”: Search backward
• “/<string>”: Search forward
• “n”: Find next of Search (backward/forward)

• “:%s/<find>/<replace>/g”: Globally replace <find> by <replace>

• “u”: Undo

• “v”: Enter visual mode (character)
• “V”: Enter visual mode (line)
• Change encoding: “:set encoding=<encoding_name>”, z.B. “:set encoding=latin1”, “:set encoding=utf-8”

• “1”: Toggle CPU display (single entry for each core/cpu)
• “k”: Select process to kill (signal 9 can not be caught by the application)

• Package conflickts: apt-get -f install and apt-get autoremove

Get information about a rpm package file: rpm -p <name>.rpm -q -filesbypkg –scripts

• Anmelden: connect sys/pw as sysdba
• Hochfahren: startup

• Insert Timestamp value: insert into table(timestamp_column) values(to_date('2010-07-08 14:30:56', 'YYYY-MM-DD HH24:MI:SS'));
• Alle aktiven Sessions anzeigen: SELECT SID, Serial#, UserName, Status, SchemaName, Logon_Time FROM V$Session WHERE Status='ACTIVE' AND UserName IS NOT NULL;
• Alle Sessions anzeigen, die andere blockieren: select blocking_session, sid, serial#, wait_class, seconds_in_wait from v$session where blocking_session is not NULL order by blocking_session;