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Console Tips&Tricks

Two dozen (un)useful one-

liners

Me, Myself and I.

❖ Ex (win) sysadmin, ex (lousy) php dev

❖ Rails developer @dlabs, still a bit lousy, getting better

❖ @miha_mencin, radiokills@github

Its all about history

$ history

…

7550 git commit -a -m 'renaming pg to postgresql in database.yml template'

7551 git push origin master

7552 git push origin postgres

7553 rake update web web1 testing

7554 bundle


7556 bundle update


…

$ cat ~/.zsh_history

…

: 1378713558:0;diff

: 1378713783:0;git commit -a -m 'duplicated_payment_details'

: 1378713798:0;git push origin duplicated_payment_details:

: 1378713805:0;git push origin duplicated_payment_details

: 1378716721:0;git checkout -b alter_service_center_payment

: 1378716812:0;rails g migration add_bank_details_to_service_center bank_account bank_sorting_code

: 1378719452:0;git commit -a -m 'migration, validation, form, DIP-257'

: 1378720670:0;git merge diplicated_payment_detail

…

Controll your history

$ echo $HISTSIZE

1000

$ echo $HISTFILESIZE

2000

$ echo $HISTFILE/home/miha/.zsh_history

$ vi ~/.zshrc

…

export HISTSIZE=10000

export HISTFILESIZE=2000

export HISTIGNORE=cd:cat:dir

…

Command line pr0n mode? Yes we can!

$ <space>vi love-letter-to-my-mistress.txt

Use your history

[CTRL] + r = (fuzzy) search through history

$ vi ~/.ssh/known_hosts

bc-i-search: vi

$ history

…

7550 git commit -a -m 'renaming pg to postgresql in database.yml template'

7551 git push origin master

7552 git push origin postgres


7554 bundle


7556 bundle update


…

$ !7556

Fetching gem metadata from https://rubygems.org/...

➜ !7556

➜ bundle update

Fetching gem metadata from https://rubygems.org/...

https://rubygems.org/

https://rubygems.org/

Re-run last command

$ ls -lahdrwxrwxr-x 3 miha miha 4.0K Jul 26 18:52 apps

-rw------- 1 miha miha 649 Jul 26 21:58 .bash_history

-rw-r--r-- 1 miha miha 220 Jul 26 12:26 .bash_logout

-rw-rw-r-- 1 miha miha 200 Jul 26 12:53 .bash_profile

-rw-r--r-- 1 miha miha 3.7K Jul 26 12:53 .bashrc

drwx------ 2 miha miha 4.0K Jul 26 12:31 .cache

drwxrwxr-x 3 miha miha 4.0K Jul 26 15:05 .gem

-rw------- 1 miha miha 41 Oct 18 09:55 .mysql_history

drwxrwxr-x 10 miha miha 4.0K Jul 26 22:03 .oh-my-zsh

…

$ fc -ln -1

ls -lah…

$ $(fc -ln -1)drwxrwxr-x 3 miha miha 4.0K Jul 26 18:52 apps

-rw------- 1 miha miha 649 Jul 26 21:58 .bash_history

-rw-r--r-- 1 miha miha 220 Jul 26 12:26 .bash_logout

-rw-rw-r-- 1 miha miha 200 Jul 26 12:53 .bash_profile

-rw-r--r-- 1 miha miha 3.7K Jul 26 12:53 .bashrc

sudo Re-run last command

(via xkcd.com)

http://xkcd.com

sudo Re-run last command

$ nginx -s reloadnginx: [alert] could not open error log file: open() "/var/log/nginx/error.log" failed (13: Permission denied)

2014/10/19 12:09:52 [warn] 1800#0: the "user" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:1

2014/10/19 12:09:52 [notice] 1800#0: signal process started

2014/10/19 12:09:52 [alert] 1800#0: kill(1007, 1) failed (1: Operation not permitted)

…

$ sudo nginx -s reload

$ sudo $(fc -ln -1)

$ sudo !!

“!!” is called ‘expansion’. !22124 is also expansion.

More about expansions

$ !!

Repeats last command

$ !2123

Repeats command 2123 from history

$ !$

Expands to last argument. For example:

$ mkdir -p /home/miha/awesome_folder/awesome_subfolder/data

$ cd !$

$ pwd

/home/miha/awesome_folder/awesome_subfolder/data

$

(Similar thing can be achieved by pressing [Esc] and then [.]

$ cd ~

We all know it

Even more expansions$ A=ruby

$ echo $A

ruby

$ A=ruby

$ echo ${#A}

4

$ A=ruby

$ echo ${A/r/ch}

chuby

$ echo ${A^}

Ruby

$ echo ${A^^}

RUBY

//use ${A,,} for downcast

Brace expansions$ echo {1,2,3}

1 2 3

$ echo file-{a,b,c}

file-a file-b file-c

$ echo {1..5}

1 2 3 4 5

$ echo {2..-3}

2 1 0 -1 -2 -3

$ echo {a..e}

a b c d e // does not work in zsh

➜ setopt BRACE_CCL

➜ echo {a-e}

a b c d e

Brace expansions

$ rm !(*.rb|*.py)

$ lsfilea1.py filea2.rb filea4.py fileb1.rb ……..

$ mv fileb1.{py,cpp}

$ cp fileb2.{py,bak}

$ touch file{a..d}{1..4}.{rb,py,css,js}

$ ls

filea1.css filea2.py filea4.css fileb1.py fileb3.css fileb4.py filec2.css filec3.py filed1.css filed2.py filed4.css

filea1.js filea2.rb filea4.js fileb1.rb fileb3.js fileb4.rb filec2.js filec3.rb filed1.js filed2.rb filed4.js

filea1.py filea3.css filea4.py fileb2.css fileb3.py filec1.css filec2.py filec4.css filed1.py filed3.css filed4.py

filea1.rb filea3.js filea4.rb fileb2.js fileb3.rb filec1.js filec2.rb filec4.js filed1.rb filed3.js filed4.rb

filea2.css filea3.py fileb1.css fileb2.py fileb4.css filec1.py filec3.css filec4.py filed2.css filed3.py

filea2.js filea3.rb fileb1.js fileb2.rb fileb4.js filec1.rb filec3.js filec4.rb filed2.js filed3.rb

file.1.rb file.2.rb file.3.rb file.4.rb filea1.rb filea2.rb filea3.rb filea4.rb filed1.rb filed2.rb filed3.rb filed4.rb

About pipes

$ ls -l | grep filea1-rw-r--r-- 1 miha staff 0 Oct 21 22:19 filea1.py

-rw-r--r-- 1 miha staff 0 Oct 21 22:19 filea1.rb

$ ls -l | grep filea1 > myfiles.txt

$ cat mayflies.txt-rw-r--r-- 1 miha staff 0 Oct 21 22:19 filea1.py

-rw-r--r-- 1 miha staff 0 Oct 21 22:19 filea1.rb

Pipes let you use the output of a program as the input of another one

Redirection makes it possible to control where the output of a command goes to,

and where the input of a command comes from. (via bash-hackers.org)

http://bash-hackers.org

Useful piping

local1$ ssh our-db-serv.net

dbserv$ mysqldump my_remote_db > my_remote_db.sql

local1$ scp our-db-serv.net:/path/to/my_remote_db.sql .

local1$ mysql my_local_db < my_remote_db.sql

$ ssh our-db-serv.net 'mysqldump my_remote_db' > my_remote_db.sql

$ mysql my_local_db < my_remote_db.sql

Task: Copy a mysql database over the ssh

But… It is so much work… And I need coffee

Still… can we do better? Yes we can!

$ ssh our-db-serv.net 'mysqldump my_remote_db' | mysql my_local_db

Not everyone’s happy

Umm, yeah…. If you’d just make it - let’s say - twice as fast…

That’d be great

Yes we can!!

Piping through ruby

$ echo "My String" | ruby -e "puts gets.downcase”

> my string

# upcase.rb

ARGF.each do |line|

puts line.upcase

end

$ ls | ruby upcase.rbFILE1.TXT

FILE2.TXT

FILE3.TXT

FILE4.TXT

UPCASE.RB

Aliases

$ alias

…

l='ls -lah'

la='ls -lAh'

ll='ls -lh'

ls='ls -G'

lsa='ls -lah'

md='mkdir -p

…

A Bash alias is essentially nothing more than a keyboard shortcut, an abbreviation,

a means of avoiding typing a long command sequence

Alias scopes

$ sudo ll

sudo: ll: command not found

$ alias sudo=‘sudo ‘

$ sudo ll-rw-r--r-- 1 miha staff 0B Oct 22 00:30 file1.txt

-rw-r--r-- 1 miha staff 0B Oct 22 00:30 file2.txt

-rw-r--r-- 1 miha staff 0B Oct 22 00:30 file3.txt

zsh specific aliases

Zsh specific aliases

-s (suffix aliases)

$ alias -s rb=subl

$ somefile.rb

# will open somefile.rb in sublime text

# we can set multiple filetypes also

$ alias -s {mkv,avi}=vlc

-g (gloabal aliases)

$ alias -g G=“| grep -i”

$ ls G filefile1.txt

file2.txt

file3.txt

file4.txt

Let’s have some fun





$ alias please='$(fc -ln -1)'

$ nginx -s reload

#error msg..

$ sudo please

$ #yeey

But… also…

$ alias bitch=‘sudo ‘

Let’s have some fun





More of zsh awesomeness

Tab completion I

Tab completion II

$ cd /u/l/b # +[TAB] =

$ cd /usr/local/bin

$ git # +[TAB] =add -- add file contents to index

am -- apply patches from a mailbox

apply -- apply patch to files and/or to index

archimport -- import an Arch repository into git

archive -- create archive of files from named tree

bisect -- find, by binary search, change that introduced a bug

blame -- show what revision and author last modified each line of a file

branch -- list, create, or delete branches

bundle -- move objects and refs by archive

cat-file -- provide content or type information for repository objects

Tab completion III


cd between subfolders

$ cd /home/miha/projects/dipstix/app/assets/javascripts

# Upsie, wrong project

$ cd dipstix playon

$ pwd

/home/miha/projects/playon/app/assets/javascripts

$ spec

zsh: correct 'spec' to 'rspec' [nyae]?

$ unsetoption correct_all

Autocorrection - can be annoying

Recursive listing

$ ls **/action_card*-rw-r--r-- 1 miha staff 530B Jul 31 14:48 app/admin/action_card_priorities.rb

-rw-r--r-- 1 miha staff 1.8K Sep 30 12:07 app/admin/action_cards.rb

-rw-r--r-- 1 miha staff 1.5K Aug 13 10:00 app/controllers/api/v1/action_cards_controller.rb

-rw-r--r-- 1 miha staff 1.2K Aug 20 15:01 app/models/action_card.rb


Edit your variables

$ vared PATH

/Users/miha/.rvm/gems/ruby-2.1.1@firely-api/bin:/Users/miha/.rvm/gems/ruby-2.1.1@global/bin:/Users/miha/.rvm/rubies/ruby-

2.1.1/bin:/Users/miha/.rvm/bin:/usr/local/heroku/bin:/usr/local/texlive/2014basic/bin/x86_64-

darwin:/usr/local/bin:/usr/local/sbin:/Users/miha/.bin:/Applications/Postgres.app/Contents/Versions/9.3/bin:/usr/local/bin:/usr/local/sbin:/

usr/bin:/bin:/usr/sbin:/sbin:/Applications/Postgres.app/Contents/Versions/9.3/bin:/bin

oh-my-zsh

oh-my-zsh is an open source, community-driven framework

for managing your Zsh configuration.

It comes bundled with a ton of helpful functions,

helpers, plugins, themes, and a few things that make you shout…

$ curl -L http://install.ohmyz.sh | sh

oh-my-useful-aliases

..='cd ..'

...='cd ../..'

1='cd -'

2='cd -2’

…

d='dirs -v | head -10’

$ d0 ~/www_rails/playon/lib/tasks

1 ~/www_rails/playon/lib

2 ~/www_rails/playon

3 ~/www_rails

4 ~/www_rails/dipstix/app

5 ~/www_rails/dipstix/app/controllers

6 ~/www_rails/dipstix/app/controllers/custom_devise

7 ~/www_rails/dipstix

8 ~/www_rails/dipstix/lib

9 ~

$ 3

~/www_rails

To sum up…

$ history | awk '{print $2}' | sort | uniq -c | sort -nr | head

2807 git

920 cd

454 ssh

382 ls

375 rails

348 ll

343 l

341 rake

291 sudo

165 rm

thnx and…

to work with us

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