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print text in colors green, cyan, blue or red (see sample output for usage)

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"

Check a server is up. If it isn't mail me.
Alternative to the ping check if your firewall blocks ping. Uses curl to get the landing page silently, or fail with an error code. You can probably do this with wget as well.

Watch Al Jazeera Livestream directly in mplayer #jan25
One cannot call the high quality livestream directly, but command this gives you a session ID and the high quality stream. #egypt #jan25

Make changes in .bashrc immediately available
Any changes to BASH shell made in .bashrc will be active in the current terminal window from the moment you execute this command, ie. aliases, prompt settings etc. No need to restart terminal. (In BASH 'source' simile to 'eval' lets you generally execute any bunch of commands stacked in a text file).

Define an alias with a correct completion
In Bash, when defining an alias, one usually loses the completion related to the function used in that alias (that completion is usually defined in /etc/bash_completion using the complete builtin). It's easy to reuse the work done for that completion in order to have smart completion for our alias. That's what is done by this command line (that's only an example but it may be very easy to reuse). Note 1 : You can use given command line in a loop "for old in apt-get apt-cache" if you want to define aliases like that for many commands. Note 2 : You can put the output of the command directly in your .bashrc file (after the ". /etc/bash_completion") to always have the alias and its completion

Backup with versioning
Apart from an exact copy of your recent contents, also keep all earlier versions of files and folders that were modified or deleted. Inspired by EVACopy http://evacopy.sourceforge.net

Remove leading zeros in multiple columns with sed
Leading zeros might help correct sorting and they can be removed by sed after sorting

Gathering all MAC's in your local network
replace eth0 with your ethernet or wireless network interface.

convert single digit to double digits
each number in a file name gets expanded to the number of digets provided as arg_1 of the arguments in rjust_file_nums. Put the funciton in the .bashrc file. Be sure to $ source ~/.bashrc so that the function will be accessible from bash.


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