Useful Scripts

Useful shell scripts. Just a random assortment of utility scripts I use. Most made for Ubuntu/Debian systems.

cloudapp

A CloudApp upload utility written by Zach Holman / @holman.

cloudapp some-picture.png

colors

A script that defines a number of environment variables that contain ANSI color codes that can be used in scripts. Simply source it at the beginning of your script and then you can do:

echo -e I'm $Color_Red using colors $Color_Off.

disk-usage

Prints out information about disk usage. Basically it runs df -h for you and then spot-checks bunch of common directories where log and temp file accumulate, runs du -shBM on them and sorts the list for you.

Requires awk.

gallery

Takes a folder paht as an argument, and generates thumbnails for all the images inside of it. Then it dumps out a HTML formatted gallery you can use on your website. The HTML is tailored to Twitter Bootstrap 3.x convetnions.

gallery /some/folder >> gallery.html

Requires imagemagic.

markdown-preview

Converts a Markdown document to html using pandoc and then opens it in elinks.

mirror

Downloads a website to be viewed locally. Pretends to be Googlebot. Very impolite and brutish script.

mirror http://example.com

Requires wget.

mj-find

Search tool for Markdown Journal. Uses Silver Searcher ag if available, or grep to find specified keyword in your jounal files.

mj-find keyword

You can configure it by defining following variables:

• JOURNAL_DIR - path to your files. Default is ~/Dropbox/Apps/Markdown\ Journal
• JOURNAL_SEARCH - either ag or grep. If not defined, defaults to ag and falls back on grep if not available.

If figlet is installed, it will use it to print logo.

mj-view

Previews this months' journal page in a web browser. Uses pandoc to convert markdown to HTML.

You can configure it by defining following variables:

• JOURNAL_DIR - path to your files. Default is ~/Dropbox/Apps/Markdown\ Journal
• JOURNAL_BROWSER - the web browser to use. Defaults to links.
• JOURNAL_PANDOC_OPTS - additional options you want to pass to pandoc. Defaults to --section-divs --title-prefix=$(date +"%B-%Y")

Tested to work under Cygwin, using the Windwows version of pandoc.exe. The script detects if it's running in a real Unix environment or in Cygwin and then runs all the paths through cygpath if needed.

mvim

Shell script passes all its arguments to the binary inside the MacVim.app application bundle. If you make links to this script as view, gvim, etc., then it will peek at the name used to call it and set options appropriately.

Based on a script by Wout Mertens and suggestions from Laurent Bihanic. This version is the fault of Benji Fisher, 16 May 2005 (with modifications by Nico Weber and Bjorn Winckler, Aug 13 2007).

packages-by-size

Lists installed packages, sorted by their size on disk. Uses dpkg-query so obviously will only work on Debian, Ubuntu and derivatives.

pngcrushdir

Runs pngcrush -brute on all the png files in a specified directory.

pngcrushdir /some/folder

It creates temp files in the same directory as it works, then deletes them. You should probably use optipng instead of pngcrush anyway.

ppa-add-key

Lets you add a ppa source if and when your outbout SSH ports are blocked by the firewall. Forces use of HTTP on port 80 to fetch the PPA keys. Must use the hex key fingerprint instead of the PPA name.

ppa-add-key C7917812

Ubuntu only for obvious reasons.

rand-passcode

Generates a very week, pseudo random pin code. Don't use it for passwords. I made it to generate weaksauce, easy to remember codes for an internal app.

recursive-line-count

Given a file extension, counts lines of code in every file with that extension in the current directory. It recurses into subdirectories.

recursive-line-count rb

remove-old-kernel-images

Lists all the kernel images currently installed on the system and gives you and option to delete all the images that are not the current one.

Uses dpkg so Ubuntu and Debian derevatives only. Requires sed.

repeats

Counts how often do you repeat a word. Counts words from STDIN or from a file. The first argument is the word to be counted. The second one is the file which is optional. If file is not specified, it expects input from STDIN.

repeats actually blogpost.md

Uses awk.

tunnel-create

Opens an SSH tunnel to a remote server using another server in the middle. This is sometimes needed if you are behind a very restrictive firewall that blocks all outbound ports.

Here is a simple use case:

• You are behind firewall. All ports other than 80 and 443 are blocked.
• You want to ssh to DESTINATION which has SSH server running on port 22
• You don't own/control DESTINATION and can't set up SSH on other port
• You do own BOUNCE, a server at your house
• You set up SSH to listen on port 443 on BOUNCE
• You want to relay traffic to DESTINATION via BOUNCE

Now run:

tunnel-create BOUNCE DESTINATION 443

This is equivalent of:

ssh -p 443 -N -T BOUNCE -L 1234:DESTINATION:22

It saves you a lot of typing and you don't have to remember the difference between -R and -L ssh options.

Run without any arguments to see usage.

tunnel-ssh

Companion script to tunnel-create. Once the tunnel is established, you can simply use this script to ssh into the remote. It assumes your username is the same on the remote as on the local machine. If not, you can pass username on remote as the first argument. It also assumes the tunnel is running on port 1234. If it's not, you can pass port as second agument.

tunnel-ssh john

This is equivalent to:

ssh -q -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 1234 john@localhost

We don't save the keys to the hosts file because you can use this script to tunnel to many different hosts. So your hosts file would be full of fake entries for localhost.

The script will check if the tunnel is open before trying to connect and quit if it is not.

tunnel-scp

As above but for scp. Allows you to easily copy files over the remote tunnel.

tunnel-scp *.html ./public_html/ john

Is equivalent of:

scp -P 1234 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no *.html john@localhost:./public_html/

It assumes the tunnel port is 1234 and that the username is the same as on local machine. It checks if tunnel is open before copying anything, and quits if its not.

updateall

Pulls ~/.dotfiles, ~/.vim and ~/scripts from their respective repositories. This is fairly unique to my config so you shouldn't use it.

vim-session-wipe

Deletes all the files in ~/.vim/session. This is where I store my session files. This might be very different for you.