行末：$
行首：^
空格：\s
行末空格：\s+$
行首空格：^\s+
删除行尾多个空格 : %s/\s+$//g
删除行首多个空格 : %s/^ +//g
删除空行：:g/^$/d
set fenc=utf-8
set fencs=utf-8,usc-bom,euc-jp,gb18030,gbk,gb2312,cp936
set nocompatible
set history=50
set tabstop=4
set number
syntax on
set showmatch
set matchtime=5
set expandtab