将原先的bash_profile中的PATH环境变量中的$PATH删除了，然后执行source ~/.bash_profile之后就出现了错误，每次打开Terminal都显示：
-bash: grep: command not found
-bash: grep: command not found
env: bash: No such file or directory
env: bash: No such file or directory
env: bash: No such file or directory
env: bash: No such file or directory
env: bash: No such file or directory
-bash: grep: command not found
-bash: cat: command not found
-bash: grep: command not found
-bash: grep: command not found
-bash: grep: command not found
-bash: grep: command not found
所有的命令都不能正常执行了，类似：top、ifconfig
都会显示：-bash: top: command not found

还请大家帮忙看看怎样恢复？？？