Hardly working hard

I am lazy. I don’t remember when it began, but to the great frustration of my mother, it has yet to end. Luckily though, there are many tools available for the lazy software engineer, some of which I’d like to share today in this post.

Too lazy to type?

I like saving key strokes. Why type when you can...not type? There are a couple of bash tricks I learned from Carlos and Jesse that I really like:

1. cd - cd to last visited directory. Everybody knows about cd ~, but this is at least as useful. Instead of taking you home, cd - takes you to the last directory you visited.

Example use case:

cd /path/to/logs

tail log1 | cut -f 3 | sort

tail log2 | cut -f 5 | sort

…

cd -

vim

2. ctrl + r: Reverse search bash history. Here at Adku, we run A LOT of map reduces. Most of the time, we’re calling the same few commands. ctrl + r lets us run, forget, and then run again later.

Example use case:

fab some_map_reduce_job:arg1=’ahhhh’,arg2=’wahhhhh’

cd ../

touch ‘asdf’

…

ctrl + r

fab

fab some_map_reduce_job:arg1=’ahhhh’,arg2=’wahhhhh’

3. !n:x-y Recall arguments x-y from the last nth command. This is another command that is a great help when running map reduces with complicated argument lists. Though, it is a lot more complicated than the other commands mentioned here, and worth reading about separately. True to the theme of this post, I redirect you to: http://www.catonmat.net/blog/the-definitive-guide-to-bash-command-line-history/ for a great resource on this, and will stick to giving a few simple examples.

Example use case(s):

>echo “foobar”

foobar

>echo “moocow”

moocow

>!-2

foobar

>!-2

moocow

--------

cat foo > impossible_to_remember_filename_akj3kj2437fvaj

nano !:3

--------

port install haskell-platform

##oh no, permission failure##

sudo !!

---------

>echo “hi” && echo “why”

hi

>!!:0-1

hi

>!-2:2-$

why

Too lazy to go to work?

Being too lazy to go to work is, of course, never a problem for me. But theoretically, I could see the following scenario occur.

1. While at work, start a ssh tunnel between your work computer and a gateway server. (For details on how we do this, checkout: http://blog.adku.com/2011/06/working-remotely.html)

2. Go home, relax.

3. Start a ssh session to your work server.

4. Start tmux

5. never go to work again.

With the exception of 4 (and 5?), this is probably a familiar process. But here’s the beauty of four:

connection closed by remote host.

Never again.

To quote the tmux man page:

Each session is persistent and will survive accidental disconnection (such as ssh(1) connection timeout) or intentional detaching (with the `C-b d' key strokes).

Aside from never losing your work due to connection problems, Tmux also makes it easy to start a job at work, go home, and continue monitoring that job remotely, or vice versa.

For example:

I start a tmux session at start tailing a random log at work:

To remember this session, I name it by typing

ctrl + b + : rename_session “foo”

Then I go home.

At home, I ssh into my work computer and type

and everything just works!

In addition to creating and naming sessions, tmux makes it easy to create and name panes within sessions. I often find myself running many jobs of the same type, which I like to organize into named panes within a single session.

The panes I have open are called “mo”, “meeny”, and “eeny”. In each screen I am running a different map reduce job. By naming the panes, I’ll remember exactly what I was running in each pane wherever I go.

Basic panel usage:

create	ctrl + b c
delete	ctrl + b x
rename	ctrl + b ,
navigate to previous panel	ctrl + b p
nagivate to next panel	ctrl + b n
navigate to panel #	ctrl + b #

Too lazy to...continue?