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Pronounce an English word using Dictionary.com
This one uses dictionary.com

Rename files in batch

Write comments to your history.
A null operation with the name 'comment', allowing comments to be written to HISTFILE. Prepending '#' to a command will *not* write the command to the history file, although it will be available for the current session, thus '#' is not useful for keeping track of comments past the current session.

Watch several log files of different machines in a single multitail window on your own machine
this way you have the multitail with all its options running on your own machine with the tails of the two remote machines inside :)

Attempt an XSS exploit on commandlinefu.com
Mouse around the title of this item, and note that your cookies are being logged to the console. If I were evil, I could instead send everyone's cookies to my site, and then post up-votes on all my submissions using their cookies, and try to delete every other submission, until clfu was completely pwned by me, redirecting people to malware and porn sites, and so on. Update - now fixed.

A function to find the newest file of a set.
Usage example: $newest Desktop/* Replace "-nt" with "-ot" for oldest. Run $shopt -s dotglob first to include dotfiles.

Read and write to TCP or UDP sockets with common bash tools
Ever needed to test firewalls but didn't have netcat, telnet or even FTP? Enter /dev/tcp, your new best friend. /dev/tcp/(hostname)/(port) is a bash builtin that bash can use to open connections to TCP and UDP ports. This one-liner opens a connection on a port to a server and lets you read and write to it from the terminal. How it works: First, exec sets up a redirect for /dev/tcp/$server/$port to file descriptor 5. Then, as per some excellent feedback from @flatcap, we launch a redirect from file descriptor 5 to STDOUT and send that to the background (which is what causes the PID to be printed when the commands are run), and then redirect STDIN to file descriptor 5 with the second cat. Finally, when the second cat dies (the connection is closed), we clean up the file descriptor with 'exec 5>&-'. It can be used to test FTP, HTTP, NTP, or can connect to netcat listening on a port (makes for a simple chat client!) Replace /tcp/ with /udp/ to use UDP instead.

Sync the existing directory structure to destination, without transferring any files

Daily watch "question pour un champion" (French TV show)
kaffeine could be replaced by any player able to read mms stream

Install pip with Proxy
Installs pip packages defining a proxy


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