alias ls='ls --color=tty -F'            "linux下用--color=tty，mac下用-G来显示颜色  
alias ll='ls -l'  
alias l='ll'  
alias grep='grep --color'
alias egrep='egrep --color'
alias rm=trash                          "防止勿删"                                                                                                                                                                     
trash()  
{   
    if [ ! -d ~/.trash ]; then mkdir ~/.trash; fi"简单判断一下
    mv $@  ~/.trash/  
}    
cleartrash()  
{    
    read -p "clear sure?" confirm  
        [ $confirm == 'y' ] || [ $confirm == 'Y' ] && /bin/rm -rf ~/.trash/* 
}