Command Line Magic

ionice -c 3 cp vm1.img vm1-clone.img # Copy a file using "ionice -c 3" to give it idle priority to reduce load on the system.

fdupes -r dir > dupes.txt # Find file duplicates in 'dir' recursively based on size and mdsum and log to dupes.txt.

awk -F: {'print $1 ":" $2'} messages |uniq -c # Count syslog hits per minute in your messages log file. Useful for doing quick stats.

One of the best fonts I've seen for use in a terminal: http://levien.com/type/myfonts/inconsolata.html …

date -d @728737200 # Turn a Unix epoch time back into a human readable date. This is a not widely known feature of the GNU date command.

rename 's/^unwanted//' *.jpg # Remove the prefix 'unwanted' from the beginning of each filename with .jpg suffix in CWD.

ssh -D 8989 you@remotehost # Create a dynamic SOCKS5 proxy on port 8989 using an SSH connection. Some apps can be configured to use this.

Option Mnemonics: tar xzvf = Xtract Ze Vucking Files [said in thick German accent]

http://bit.ly/13mBzf0  # Useful python command line one liners.

comm -3 <(ls -1 dir1) <(ls -1 dir2) # Compare the contents of 2 dirs. Show only 2 columns, each for files unique to the directory.

sleep 15m; notify-send "Go pick up the pizza" # Remember to go get the food. In X, this will send a notification to the screen.

qalc "145Gibyte / 1.35(Mibyte/second) to day" # How many days will it take to transfer 145GiB at 1.35MiB/sec? Use qalc!

lsof -Pan -i tcp -i udp # show all listening TCP/UDP ports

pv bigdump.sql.gz | gunzip | mysql # restore a #mysql dump with progressbar and ETA.

cat longdomainlist.txt | rev | sort | rev # group subdomains by domain. Good use of rev..

diff <(grep = config.txt) <(grep = config.txt-new) # Compare just the assignment lines of two config files that use = for value assignment.

ps aux | awk '{if ($8=="Z") { print $2 }}' # On Linux, print out a list of the process IDs that are in the zombie state.

exec -a vim nethack # Now if your boss runs ps aux on your system, they will think you're working, not playing a game.

HISTIGNORE="clear:bg:fg:cd:cd -:exit:date:w:* --help" # Colon seperated list of exact commands to ignore for storing in history in BASH.