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Set gnome wallpaper to a random jpg from the specified directory
Every time this is run it will change your background picture. For added fun Add some DBUS magic: . $HOME/.dbus/session-bus/`cat /var/lib/dbus/machine-id`-0 export DBUS_SESSION_BUS_ADDRESS and a crontab entry: */5 * * * * above_command_in_script.sh >/dev/null 2>/dev/null now wallpaper changes every 5 mins

Display a block of text with AWK
I find this terribly useful for grepping through a file, looking for just a block of text. There's "grep -A # pattern file.txt" to see a specific number of lines following your pattern, but what if you want to see the whole block? Say, the output of "dmidecode" (as root): $ dmidecode | awk '/Battery/,/^$/' Will show me everything following the battery block up to the next block of text. Again, I find this extremely useful when I want to see whole blocks of text based on a pattern, and I don't care to see the rest of the data in output. This could be used against the '/etc/securetty/user' file on Unix to find the block of a specific user. It could be used against VirtualHosts or Directories on Apache to find specific definitions. The scenarios go on for any text formatted in a block fashion. Very handy.

Configure second monitor to sit to the right of laptop
You'll need to make sure your xorg.conf permits a virtual screen size this big. If it doesn't then xrandr should return a suitable error message that tells you the required size.

Bypass with hexencoding, dump /etc/passwd

Use mplayer to save video streams to a file
I use this command to save RTSP video streams over night from one of our national TV stations, so I won't have to squeeze the data through my slow internet connection when I want to watch it the next day. For ease of use, you might want to put this in a file: #!/bin/bash FILE="`basename \"$1\"`" mplayer -dumpstream -dumpfile "$FILE" -playlist "$1"

Gzip files older than 10 days matching *
Useful for a cron job that runs nightly, gzipping or alternatively deleting files from a specific directory that are older than 10 days (in this case)

Migrate Server with rsync
Copies the complete root-dir of a linux server to another one, where the new harddisks formated and mountet. Very useful to migrate a root-server to another one.

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Command to rename multiple file in one go
An entirely shell-based solution (should work on any bourne-style shell), more portable on relying on the rename command, the exact nature of which varies from distro to distro.

Swap the two last arguments of the current command line
Say you just typed a long command like this: $ rsync -navupogz --delete /long/path/to/dir_a /very/long/path/to/dir_b but you really want to sync dir_b to dir_a. Instead of rewriting all the command line, just type followed by , and your command line will read $ rsync -navupogz --delete /very/long/path/to/dir_b /long/path/to/dir_a


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