�ݺ�ߣ

L ve the Terminal
Because life is better when you can
work on the command line

Mike West
Yahoo! Frontend Summit, Dec. 2007
�ݺ�ߣs:
http://mikewest.org/?le_download/12

The command line is complex, and
quite impossible to cover fully.

So let��s begin by limiting our scope.

Foundations
Unix-style systems all behave according to
similar rules; understanding those
underlying ideas and processes is critical.

Connectivity
My computer is a paperweight without a
network; I need to get secure access to
many remote machines, and do things there.

Scripting
Don��t type the same things over and over;
save your sanity with just a little
understanding of Bash aliases and functions.

Foundations

http://?ickr.com/photos/johnseb/458716114/

Foundations

Unix-style systems are built
primarily on small, single-purpose
utilities that can be chained
together for larger effect.


Foundations

Each of these tools operates in one
way or another on streams.


Foundations

STDOUT

$> ls
file-1.txt file-2.txt
$>


Foundations

STDIN

$> perl
$x = ��Hello, world!��;
print quot;n$xnquot;;
^D
Hello, world!
$>


Foundations

STDERROR

$> perl
$x = 1/0; print quot;n$xnquot;;
Illegal division by zero at - line 1.
$>


Foundations

Stream Redirection


Foundations

Input Redirection: `<`

mikewest:~/some_dir westm$ validator < ./tmp.html

mikewest:~/some_dir westm$


Foundations

Output Redirection: `>` and `>>`

mikewest:~/some_dir westm$ ls > ./tmp



Foundations

Error Redirection: `2>`

mikewest:~/some_dir westm$ errorful 2> ./dev/null

mikewest:~/some_dir westm$ errorful > ./dev/null 2>&1



Foundations

Chaining Streams


Foundations

Small Utilities, Working Together: `|`

$> ls -la | sort -r -k 5 | head -3
-rw-r--r-- 1 westm westm 34749 Oct 19 12:11
SiteAssistant.js
-rw-r--r-- 1 westm westm 12292 Oct 18 22:51 .DS_Store
-rw-r--r-- 1 westm westm 8161 Oct 19 11:35
SiteAssistant.css

Lists the 3 (`head`) largest (`sort`) ?les in the current directory (`ls`)


Foundations

Permissions System


Foundations

Each ?le has an ��owner��, a ��group��,
as well as 3 sets of execute, read,
and write permission bits.


Foundations

$> ls -lah
-rw-r--r-- 1 westm westm 2K Aug 2 2001 xmalloc.c
$> chmod 777 xmalloc.c
$> ls -lah
-rwxrwxrwx 1 westm westm 2K Aug 2 2001 xmalloc.c

1 --x execute
2 -w- write
3 -wx write and execute
4 r-- read
5 r-x read and execute
6 rw- read and write
7 rwx read, write and execute


Foundations

Process Control


Foundations

You can start processes in the
background with `&`, pause
processes with Crtl-Z, and deal
with paused processes using `fg`
and `bg`.


Foundations

Demo go herquot;


Foundations

Editing Files


Foundations

Avoid holy wars; just use VIM.


Connectivity

http://www.?ickr.com/photos/hi-phi/36854889/

Connectivity

Whatever your connectivity needs,
SSH is almost certainly the answer.


Connectivity

Passwords are annoying

L
mikewest:~ westm$ ssh mikewest@mikewest.org

I
Password:
Last login: Thu Nov 29 11:45:59 2007 from 193.93.196.161
_____________________________________

A
________| |_________
| girard.joyent.us | /
| | /

F
| quot;Mrs. Robinson, you're trying | /
| to seduce me. Aren't you?quot; | /
/ |_____________________________________|
/___________) (___________

[girard:~] mikewest$


Connectivity

SSH Keys are much better


Connectivity

SSH Keys are much friendlier and
are trivial to create and use.


Connectivity

Just run `ssh-keygen`
mikewest:~ westm$ ssh-keygen -t rsa -b 2048
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/westm/.ssh/
id_rsa): /Users/westm/.ssh/test_rsa
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /Users/westm/.ssh/
test_rsa.
Your public key has been saved in /Users/westm/.ssh/
test_rsa.pub.
The key fingerprint is:
8f:0b:e7:ea:17:61:69:6a:11:06:f5:56:ac:70:c4:69
westm@mikewest.munich.corp.yahoo.com

Connectivity

Upload to the server, and append to
~/.ssh/authorized_keys

mikewest:~ westm$ scp /Users/westm/.ssh/test_rsa.pub
mikewest@mikewest.org:~/.ssh/authorized_keys


Connectivity

Of course, you will create
passphrased keys, because
anything else is idiocy.


Connectivity

SSH Agent


Connectivity

SSH Agent is Easy

mikewest:~ westm$ eval `ssh-agent`
Agent pid 80094
mikewest:~ westm$ ssh-add
Enter passphrase for /Users/westm/.ssh/id_rsa:
Identity added: /Users/westm/.ssh/id_rsa (/Users/
westm/.ssh/id_rsa)
mikewest:~ westm$


Connectivity

SSH Agent + Screen


Connectivity

Demo go herquot;


Scripting

http://www.?ickr.com/photos/mortimer/221051561/

Scripting

Elimination of mindless repetition
from your daily life is essential to
your continued sanity.


Scripting

Uploading SSH Keys, for instance.
#!/bin/bash

KEY=quot;$HOME/.ssh/id_rsa.pubquot;

if [ -z $1 ];then
echo quot;Usage: `upload_keys username@host`quot;
else
echo quot;Putting your key on $1... quot;
ssh -q $1 - HEREDOC
umask 0077;
mkdir -p ~/.ssh;
echo quot;`cat $KEY`quot; ~/.ssh/authorized_keys
echo quot;done!quot;
HEREDOC
fi

Scripting

Aliases

mikewest:~ westm$ ll
-/bin/bash: ll: command not found
mikewest:~ westm$ alias ll=��ls -lah��
mikewest:~ westm$ ll
magically insert result of `ls -lah` here
mikewest:~ westm$


Scripting

Functions

mikewest:~ westm$ httpload() {
echo quot;http://$1quot; /var/tmp/$1.http_load_temp_file
http_load -parallel $2 -seconds $3 /var/tmp/
$1.http_load_temp_file
rm -f /var/tmp/$1.http_load_temp_file
}
mikewest:~ westm$ httpload mikewest.org 1000 1000000
magically insert my crashing, burning website here
mikewest:~ westm$


Scripting

You can put frequently used
functions or aliases into
`~/.bash_login` so they��re available
immediately.


Questions?
Mike West
mike@mikewest.org
http://mikewest.org/

�ݺ�ߣ

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