# vi ~/.bash_history

 清空里面的记录，并退出当前shell

# exit（一定要退出当前shell）
# history
    1  vi ~/.bash_history 
    2  history |grep mysql
    3  clear
    4  vi ~/.bash_history 
    5  echo "" > ~/.bash_history 
    6  vi ~/.bash_history 
    7  history
    8  exit
    9  history
#之前的内容被清空！！！

[root@localhost ~]# history
    1  history
    2  echo "" > ~/.bash_history 
    3  history
[root@localhost ~]# history -c #也可以清空历史命令
[root@localhost ~]# history
    1  history

 history不记录历史命令：

#vi /etc/profile
#HISTSIZE=1000
HISTSIZE=6 #记录历史命令的条数；HISTSIZE=0为不记录

 记得重新载入：

# source /etc/profile