Learn you some shell for your own good

$ Learn you some shell for your own good (A
shell introduction* for Ember developers) * absolutely non exhaustive ** some concepts might be simplified

@ghedamat @unspace

Let’s talk about ember

Let’s talk about the shell #!/bin/bash sh — shell, the
standard command language interpreter (source $man shell)

What is it and why should I care? * Main
interface to the OS * It’s everywhere * You use it every day * Not just a task runner

There’s not only one * sh - the beginning *
bash (Bourne Again SHell) * zsh - it’s good * commands (like cd, ls, cp…)are separate * some commands can differ between Linux/OSX/bsd

Part 1 - Commands Do one thing and do it
well

$ man displays manual pages for commands (yes you can
do $ man man)

$ cd change (working) directory (if no directory given go
to $HOME) ($HOME is your usually /home/user) ($HOME is aliased to ~)

$ cd - go to previous directory every `cd` sets
$OLDPWD to the last visited directory

$ pwd print working directory in case you’re lost

$ ls list directory contents * -lh (list nicely and
human readable sizes) * -a (shows hidden files) * -t (sort by most recent)

$ cp copy files (cp -r mydir destdir/) * -r
recursive * copies mydir into destdir * beware OSX (cp mydir/ destdir/ copies content of mydir)

$ mv move files * no need for -r

$ which shows the path of a command * which
ls /bin/ls

$ watch executes a command periodically * useful to “watch”
for operations * watch ls -lh filename

$ cat concatenate files and print * get the content
of a file immediately * useful for scripting * `dog` is a valid alternative (no kidding)

$ less quickly read through a file * scroll around
with keyboard * vim keys * less - opposite of more (from the man)

$ tail output last part of a file * -n
lines from end of file * -f keep waiting for updates * --pid=ID stops watching when pid dies

$ touch change file timestamp (or create it)

$ df $ du monitor space usage of disk or
directory * -h is your friend

$ find find files * find PATH -name PATTERN

$ grep print lines matching a pattern * -r grep
in files recursively * -i case insensitive (slow)

$ ack $ ag grep for code * much better

use <TAB> tab completion is awesome * configure it properly
* completion for command’s options

$ pushd/popd - dirs change directory by using a stack
* pushd `cd` and pushes it onto the stack * popd pops the first one and `cd` to i * dirs shows the current stack * cd +N -N

There are MANY more rm, cut, tail, head, dd, echo...

1: Learn some commands just pick one and try to
use it

Part 2 - Navigation Don’t use the arrows (mostly emacs
navigation)

ctrl-f ctrl-b move to next/previous char on the line $
alt-a | alt-e moves by word

ctrl-a ctrl-e beginning/end of line

ctrl-s ctrl-r search forward/backward * you always have a command
history * $ cat ~/.bash_history

ctrl-p ctrl-n previous/next command in the history

2: Don’t use the arrows shortcuts are faster * tip:
remap CAPS to CTRL

Part 3 - Editing change the line

ctrl-u kill line * kill means delete

kill until end of line ctrl-k

* kill prev word * kill prev char * kill
next char ctrl-w ctrl-h ctrl-d

enter current line ctrl-o

clear screen * same as `clear` ctrl-l

switch chars * useful for typos * sl -> ls
ctrl-t

edit current line in $EDITOR * you can set a
default editor for the terminal * great for complex commands ctrl-x ctrl-e

3: Edit the line it’s ok to make mistakes *
psss: there’s a vim mode too...

Part 4 - Processes to kill or to sleep (ask
me about signals later)

kills current process * easy way out * sends SIGINT
* (it’s actually way more complicated than that) ctrl-c

suspend current process * returns you to the shell *
process is “on-hold” * sends SIGTSTP ctrl-z

sends <command> to the background * you can also suspend
and then call ‘bg’ $ <command> &

jobs: list jobs and their statuses fg [N]: resumes a
job $ jobs $ fg

$ ps $ top know your processes * ps aux
| print list of processes * top | interactive interface * htop | fancier top

4: Multitask you can do a lot in one shell

Summary 1: Learn some commands 2: Don’t use the arrows
3: Edit the line 4: Multitask

That’s it?

Not at all...

..but I’ll stop...

...for now :)

Thanks! @ghedamat (Unspace)

Extras:

Part 5 - Redirects & Pipes in and out

> redirect output to file * >> redirects and appends
to file * cat filename >> otherfile

< redirect input from file * sets the stdin for
a command * cat < filename

| “pipe” the output of a program into the input
of another $ ls -l | grep -i name

Part 6 - Replace change is good

$ cp file{.txt,.meow} bash string manipulation * can do MUCH
more than this

$ sed transform text * sed -i -r ‘s/wow/meow/g’ *
good for scripts

Part 7 - Tools add good stuff

get a shortcut opening a terminal should be FAST *
alt+x is my favorite

$ autojump $ fast remember where you cd gets you
there fast * j fuzzymatchagainstpath

$ screen $ tmux multiplex your terminal * great for
servers * even better for development * tiling is good

$ tmuxinator predefined tmux configurations * quickly boot a project
(webserver, test runner, logs, editor)

$ tmate tmux based pairing env * insanely good *
(you need to use a terminal editor)

Ok, Enough...

...but feel free to ask more!

Thanks!! @ghedamat (Unspace)

Learn you some shell for your own good

Learn you some shell for your own good

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