Determinant of a 2 × 2 matrices

$$\left| {\matrix{ a & b \cr c & d \cr } } \right| = ad - bc$$

隐藏文件

chflags hidden filename

显示文件

chflags nohidden filename

文件链接

ln -s /path/to/desired-folder ~/Dropbox/desired-folder

安装编译

Let's call this directory 'source_dir' (where this INSTALL file is). Before starting, create another directory which we will call 'build_dir'.

Do:

cd build_dir
cmake source_dir
make install

The "make install" step may require administrator privileges.

You can adjust the installation destination (the "prefix") by passing the -DCMAKE_INSTALL_PREFIX=myprefix option to cmake, as is explained in the message that cmake prints at the end.

删除

If you have a manifest file which lists all the files that were installed with make install you can run this command which I have from another answer:

cat install_manifest.txt | xargs echo rm | sh

If you have sudo make install you will need to add a sudo to your uninstall:

cat install_manifest.txt | xargs echo sudo rm | sh

基础库

sudo apt-get install git-core
sudo apt-get install g++
sudo apt-get install cURL

安装Node.js

hexo官方推荐的安装方法是使用nvm，这里我们也使用nvm进行安装，当然你也可以使用直接安装，不过貌似nvm安装之后会直接在个人目录下产生.nvm目录并且通过.bashrc或者.bash_profile进行开机加载，然后其他的nvm操作都会保存在>.nvm目录，这样方便以后升级或者重装系统，相当于绿色软件了。

wget -qO- https://raw.github.com/creationix/nvm/master/install.sh | sh
reboot
nvm install 4
nvm ls

会输出：

v4.2.6
node -> stable (-> v4.2.6) (default)
stable -> 4.2 (-> v4.2.6) (default)
iojs -> N/A (default)

然后：

nvm use 4.2.6
nvm alias default 4.2.6

为了避免重启后找不到hexo指令的错误，在/etc/rc.local中添加：

nvm use 4.2.6

安装，配置Hexo

npm install -g hexo-cli

#在home新建一个文件夹,用于本地存放博客
$mkdir Blogs
$cd Blogs

#用hexo命令在Blogs目录中初始化环境
$hexo init
$npm install

#本地服务开启
hexo server
INFO  Hexo is running at http://0.0.0.0:4000/. Press Ctrl+C to stop.

可以通过ip:4000查看到默认页面。

安装Dropbox

32-Bit:

wget -O - "https://www.dropbox.com/download?plat=lnx.x86" | tar xzf -

64-Bit:

wget -O - "https://www.dropbox.com/download?plat=lnx.x86_64" | tar xzf -

接着，从新建的 .dropbox-dist 文件夹运行 Dropbox 守护程序。

~/.dropbox-dist/dropboxd

Next we will download the command line management script. This script requires Python, so make sure you have it installed. You can see if Python is installed with python -V

wget https://www.dropbox.com/download?dl=packages/dropbox.py -O dropbox_manager.py

chmod +x dropbox_manager.py

./dropbox_manager.py

如果想要不同步某些文件夹，就可以：

./dropbox_manager.py exclude add ~/Dropbox/Photos/

Running Dropbox on system startup

Here's a sample init.d script for Debian/Ubuntu and the event.d sample.

sudo nano /etc/init.d/dropbox

输入:

#!/bin/bash
# dropbox service
DAEMON=.dropbox-dist/dropboxd

start() {
    echo "Starting dropbox..."
    if [ -x /root/$DAEMON ]; then
       HOME="/root" start-stop-daemon -b -o -c root -S -u root -x /root/$DAEMON
    fi
}
 
stop() {
    echo "Stopping dropbox..."
    if [ -x /root/$DAEMON ]; then
        start-stop-daemon -o -c root -K -u root -x /root/$DAEMON
    fi
}
 
status() {
    dbpid=`pgrep -u root dropbox`
    if [ -z $dbpid ]; then
        echo "dropboxd not running."
    else
        echo "dropboxd running (pid $dbpid)"
    fi
}
 
 
case "$1" in
  start)
    start
    ;;
 
  stop)
    stop
    ;;
 
  restart|reload|force-reload)
    stop
    start
    ;;
 
  status)
    status
    ;;
 
  *)
    echo "Usage: /etc/init.d/dropbox {start|stop|reload|force-reload|restart|status}"
    exit 1
 
esac
 
exit 0

Set it to start automatically on system boot:

sudo chmod +x /etc/init.d/dropbox
sudo update-rc.d dropbox defaults

To start the service, run

sudo /etc/init.d/dropbox start

To stop it, run

sudo /etc/init.d/dropbox stop

To restart it, run

sudo /etc/init.d/dropbox restart

You can also check running status in the Ubuntu/Debian and Gentoo versions with:

sudo /etc/init.d/dropbox status

部署Nginx

sudo apt-get install nginx

sudo vim /etc/nginx/conf.d/blog.conf

写入：

server {
    listen 80;
    server_name example.com;  # 自己的域名

    root /home/xxx/public;  # 刚才说的路径
    access_log  /var/log/nginx/blog_access.log;
    error_log   /var/log/nginx/blog_error.log;
    
    # 这里是针对静态资源文件做个缓存
    location ~* \.(?:ico|css|js|gif|jpe?g|png)$ {
        expires 1d;
        add_header Pragma public;
        add_header Cache-Control "public";
    }

    #  这里就是把请求转给我们的静态文件了
    location / {
        try_files $uri $uri/ /index.html;
    }
}

如果使用了hexo-pdf插件，并且将文件放到服务器上，则还需添加：

location ~* \.(pdf)$ {
    add_header "Access-Control-Allow-Origin" "http://nagland.github.io";
}

由于nginx的运行用户没有权限访问网站所在的目录，检查^[1]：

/etc/nginx/nginx.conf

可以将user的值改为当前用户名。

重启：

service nginx restart