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Find usb device in realtime
Using this command you can track a moment when usb device was attached.

search for files or directories, then show a sorted list of just the unique directories where the matches occur
Ever use 'locate' to find a common phrase in a filename or directory name? Often you'll get a huge list of matches, many of which are redundant, and typically the results are not sorted. This command will 'locate' your search phrase, then show you a sorted list of just the relevant directories, with no duplications. So, for example, maybe you have installed several versions of the java jre and you want to track down every directory where files matching "java" might exist. Well, a 'locate java' is likely to return a huge list with many repeated directories since many files in one directory could contain the phrase "java". This command will whittle down the results to a minimal list of unique directory names where your search phrase finds a match.

Get a list of all your VirtualBox virtual machines by name and UUID from the shell
A similar command that lists only the currently running VMs is thus: $ VBoxManage list runningvms ...the above showing a list of VMs by name and UUID in the same format as the "$ VBoxManage list vms" command

Watch the progress of 'dd'
Running this code will execute dd in the background, and you'll grab the process ID with '$!' and assign it to the 'pid' variable. Now, you can watch the progress with the following: $ while true; do kill -USR1 $pid && sleep 1 && clear; done The important thing to grasp here isn't the filename or location of your input or output, or even the block size for that matter, but the fact that you can keep an eye on 'dd' as it's running to see where you are at during its execution.

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.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Mount a Windows share on the local network (Ubuntu) with user rights and use a specific samba user

Create a tar file with the current date in the name.
Same, but count of signs is little less :) .

ping a host until it responds, then play a sound, then exit
Audio acknowledgement for host availability. When running the command from a Linux systems, you can use "festival" or "espeak" instead of "say".

Convert IP octets to HEX with no dots.
Converts IP octets to hex using printf command. Useful for generating pxeboot aliases in the pxelinux.cfg folder.


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