Commands by wires (15)

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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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 the excellent EVACopy

extract email adresses from some file (or any other pattern)
find all email addresses in a file, printing each match. Addresses do not have to be alone on a line etc. For example you can grab them from HTML-formatted emails or CSV files, etc. Use a combination of $...|sort|uniq$ to filter them.

ANSI Terminal Color Test using python
Pre-packaged python script that comes with Debian/Ubuntu.

Create QR codes from a URL.
QR codes are those funny square 2d bar codes that everyone seems to be pointing their smart phones at. Try the following... $ qrurl Then open qr.*.png in your favorite image viewer. Point your the bar code reader on your smart phone at the code, and you'll shortly be reading xkcd on your phone. URLs are not the only thing that can be encoded by QR codes... short texts (to around 2K) can be encoded this way, although this function doesn't do any URL encoding, so unless you want to do that by hand it won't be useful for that.

Unrar multiple directories into current working directory
Grabs all rar files in any current subdirectories and feeds it to unrar. Doesn't work well with things packaged like file.part01.rar. Works best with File.rar. You can recurse into other directories by adding more /*'s

Sort files in folders alphabetically
Creates one letter folders in the current directory and moves files with corresponding initial in the folder.

Binary Clock
Binary clock with separate H:M:S.

Batch resize all images in the current directory that are bigger than 800px, height or weight.
You need to install imagemagick. On Debian type: # apt-get install imagemagick

Generates a TV noise alike output in the terminal
Generates a TV noise alike output in the terminal. Can be combined with

Grab an interface's IP from ifconfig without screen clutter
Sometimes, you don't really care about all the other information that ifconfig spits at you (however useful it may otherwise be). You just want an IP. This strips out all the crap and gives you exactly what you want.

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