0 切换目录 cd

1 查看当前目录 pwd

2 生成目录 mkdir

3 搜索文件

4 查看当前的文件 ls

5 删除文件但保留特定类型 rm !(*)
例如： rm !(.tex|.eps)其中，.tex, .eps格式的文件会被保留下来。

6 打开pdf文档

gnome-open xxx.pdf (用系统默认的软件打开pdf，在我的电脑上就是Foxit reader)
evince xxx.pdf (用evince打开pdf, 这个是linux系统默认自带的工具，不能对pdf做任何注释和修改，但优点是快速稳定)
content

7 equivalent bash command
to rename a bash variable/command

alias fire='firefox'
fire

similar way is to set environment variable

export fire=firefox

however when you wish to use this variable, you need call it with a '$'

$fire

8 find files or directory

• find

# find file by filename
find /etc/path -name filename.type
# find file by size bigger than 1M
find /etc/path -size +1M

• grep

### grep 'texts' d*

9 view file content
you can use 'more' command to view a file, you can also use 'vim' to view a file, under vi mode you can modify a file, under more modle you can make any modification to your file. eg:

vi ~/.bashrc
more ~/.bashrc

10 bash variable

• read bash variable
  To know the content of a bash variable name, you can use the above command.

echo variablename

11 environment path setting

• non interective environment file: /etc/profile; ~/.bash_profile
  this environment setting will be loaded every time you run a bash command.
• interective environment file: /etc/bashrc; ~/.bashrc
  this environment setting will be loaded only once when you first log in as a user.
  The bash environment files under /etc/ are configured by root for all users, normal user can only view them without any modification.
  When you have made any change to bash environment setting file, you need to make them available by executing the above command.

source ~/.bashrc ~/.bash_profile

12 give file access permission

chmod 777

13 SFTP远程文件访问
通过sftp可以远程访问服务器的文件，并且可以通过get命令将文件复制到本地

sftp username@serverIP
cd proper/location
get -r foldername
get filename.type
exit

参考：
[1]https://askubuntu.com/questions/43264/how-to-open-a-pdf-file-from-terminal