start up engineering notes

<pre>最近在学习start-up engineering 的公开课,做了一些notes,保持更新</pre>

notes

---

ssh to amazon server

chmod 400 mykepair.pem
ssh -i mykeypair.com ec2-54....compute.amazonaws.com

• fast way

mkdir -p ~/.ssh
cp ~/downloads/skey.pem ~/.ssh/
chmod 400 ~/.ssh/skey.pem
chmod 700 ~/.ssh
nano ~/.ssh/config # edit the file as shown below
cat ~/.ssh/config
Host awshost1
HostName ec2-54-218-35-71.us-west-2.compute.amazonaws.com
 User ubuntu
 IdentityFile "~/.ssh/skey.pe

• connect

ssh awshost1
ssh awshost1 uptime

list all environmental variables

env

common commands

echo $PATH
alias ll='ls -alrth'
sudo apt-get install -y git-core
which git

copy files between remote machines

scp -i keypair.pem hello.txt amazonserver:~/
scp hello.txt awshost1:~/
scp hello.txt awshost1:~/foo.txt

remote sync

rsync -avp something.txt awshost4:~/
...
rsync -avp something.txt awshost4:~/
...

install node and npm

$ sudo apt-get update
# Install a special package
$ sudo apt-get install -y python-software-properties python g++ make
# Add a new repository for apt-get to search
$ sudo add-apt-repository ppa:chris-lea/node.js
# Update apt-get’s knowledge of which packages are where
$ sudo apt-get update
# Now install nodejs and npm
$ sudo apt-get install -y nodejs

Hello world

#!/usr/bin/env node
console.log("Hello World");

Hello world 2

#!/usr/bin/env node
var fs = require(’fs’);
var outfile = "hello.txt";
var out = "Modify this script to write out something different.\n";
fs.writeFileSync(outfile, out);
console.log("Script: " + __filename + "\nWrote: " + out + "To: " + outfile);

Fibonacci

#!/usr/bin/env node
// Fibonacci
// http://en.wikipedia.org/wiki/Fibonacci_number
var fibonacci = function(n) {
if(n < 1) { return 0;}
else if(n == 1 || n == 2) { return 1;}
else if(n > 2) { return fibonacci(n - 1) + fibonacci(n - 2);}
};

 // Fibonacci: closed form expression
 // http://en.wikipedia.org/wiki/Golden_ratio#Relationship_to_Fibonacci_sequence
 var fibonacci2 = function(n) {
 var phi = (1 + Math.sqrt(5))/2;
 return Math.round((Math.pow(phi, n) - Math.pow(1-phi, n))/Math.sqrt(5));
 };
 // Find first K Fibonacci numbers via basic for loop
var firstkfib = function(k) {
var i = 1;
var arr = [];
for(i = 1; i < k+1; i++) {
arr.push(fibonacci(i));
}
return arr;
};
 // Print to console
 var fmt = function(arr) {
 return arr.join(" ");
 };
 var k = 20;
 console.log("firstkfib(" + k + ")");
 console.log(fmt(firstkfib(k)));
 

heroku

• install git

sudo apt-get install -y git-core
which git

• install heroku

wget -qO- https://toolbelt.heroku.com/install-ubuntu.sh | sh
which heroku
 heroku login
ssh-keygen -t rsa
heroku keys:add

• deploy application to heroku

## Clone a sample repo and push to heroku
git clone https://github.com/heroku/node-js-sample.git
cd node-js-sample
heroku create
git push heroku master

The Cloud and IAAS/PAAS/SAAS

IAAS: (infrastructure as a service)AWS, Joyent, Rackspace Cloud
PAAS: (platform at a service)Heroku, DotCloud, Nodester, Google AppEngine
SAAS: (software as a service)Salesforce, Google Apps, Mint.com

dealing with links

wget -w 2 -r -np -k -p http://www.stanford.edu/class/cs106b
curl https://install.meteor.com | less #

split large files

split -d -l 1000 *ptt subset.ptt.
ll subset.ptt*

archive and compress file

mkdir genome
mv *ptt* genome/
tar -cvf genome.tar genome
gzip genome.tar
tar -xzvf genome.tar.gz

sed and awk

sed ’s/\r/\n/g’ windows-newline-file.csv
tail -n+4 *ptt | awk -F"\t" ’{print $2, $3, $3 + 5}’ | head

xargs and tee

find /etc -name ’*\.sh’ | xargs head -2
ls | tee list.txt

install screen

cd $HOME
wget raw.github.com/startup-class/dotfiles/master/.screenrc -O .screenrc
head .screenrc
screen

install emacs (wrapped in a setup.sh in startup class)

cd $HOME
sudo apt-get install -y git-core # if you haven’t already
git clone https://github.com/startup-class/setup.git
./setup/setup.sh
npm install -g jshint ## for javascript highlight

about git

sudo apt-get install -y git-core
mkdir myrepo
cd myrepo
git config --global user.name "John Smith"
git config --global user.email "example@stanford.edu"
git init
# Initialized empty Git repository in /home/ubuntu/myrepo/.git/
git status
echo -e ’line1\nline2’ > file.txt
git status
git add file.txt
git status
git commit -m "Added first file"
git log
echo -e "line3" >> file.txt
git status
git diff file.txt
git add file.txt
git commit -m "Added a new line to the file."
git log
git log -p
git log -p --color

• github

git clone github.com/somelinks....master.git
git add ...
git commit -m "commit message"
git push origin master
ssh-keygen -t rsa -C "foo@stanford.edu"
ssh -T git@github.com
git push -u origin master 

<pre>
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(to be continued)
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