su命令后输入密码就显示: command not found

aoloverhua

FC6系统突然间每次su命令后输入密码就显示
[root@Aolover ~]# su
: command not found
: command not found
': not a valid identifier
: command not found
: command not found
: command not found
: command not found
在root下同样
输入echo $PATH显示
:/usr/bin:/usr/sbin:/bin:/sbin:/usr/X11R6/binb/jre1.5.0_10
请问如何解决？

yongjian

get rid of the first ":" in your PATH

寂寞烈火

try:
su -

Iambitious

能给解释一下为什么这样吗？