nix

TagList也是很好用vim的plugin，功能太多啦，有點懶，就是寫些最基本的介紹了。

TagList的網頁是：

• SED is a stream editor. A stream editor is used to perform basic text transformations on an input stream (a file or input from a pipeline).

• General Syntax of sed:
  sed -option 'general expression' [data-file]
  

• General Syntax of awk: awk -f {awk program file} filename

• The format of awk program looks like:

[pattern] {
Action 1

大部分的純文字編輯器都有多視窗編輯的功能，非常的方便，其實vim也有，在www.vim.org可以找到這個好用的plugin，完整的網址如下：

http://www.vim.org/scripts/script.php?script_id=1338

使用起來也很方便，把下載的tabbar.vim放在Linux環境下的$HOME/.vim/plugin或Windows環境下的C:\Program Files\Vim\vimfiles\plugin就可以啦。

• /dev/null - Use to send unwanted output of program
  Syntax: command > /dev/null
  $ls > /dev/null
• Normally all our variables are local. Local variable can be used in same shell, if you load another copy of shell (by typing the /bin/bash at the $ prompt) then new shell ignored all old shell's variable.
• Conditional execution
  

• if condition
  Syntax:
  if condition
  

• Shell Script is series of command written in plain text file.
• To find all available shells in your system type following command:
  $cat /etc/shells
• To find your current shell type following command
  $ echo $SHELL
• Example: