对的：

The Unix C shell hashes your search path directories to help it find executables faster. But it develops blind spots if you add new executables to those directories after it's already done its hash. The solution is to use the rehash command to tell it to rebuild its hash. Alternately, you can turn off the path hash entirely (taking a slight performance hit) using the unhash command.

【 在 freesand (freesand) 的大作中提到: 】
: zsh需要输个rehash，csh大概也是吧
--
FROM 116.233.73.*