用别名覆盖内置命令 [英] Override a builtin command with an alias

问题描述

我正在尝试创建一个覆盖cd命令的别名.这将在真实" cd之前和之后执行脚本.

I am trying to make an alias that overrides the cd command. This is going to execute a script before and after the "real" cd.

这是我到目前为止所拥有的:

Here is what I have so far:

alias cd="echo before; cd $1; echo after"

这会执行echo before和echo after command，但它会始终更改目录~

This executes the echo before and echo after command however it always changes directory ~

我该如何解决?

我也尝试过cd(){ echo before; cd $1; echo after; }，但是它反复地重复"before".

I also tried cd(){ echo before; cd $1; echo after; } however it repetedly echos "before".

推荐答案

我也尝试过cd(){ echo before; cd $1; echo after; }，但是它反复地重复"before".

I also tried cd(){ echo before; cd $1; echo after; } however it repetedly echos "before".

因为它递归调用您定义的cd.要解决此问题，请使用builtin关键字，例如:

because it calls recursively the cd defined by you. To fix, use the builtin keyword like:

cd(){ pwd; builtin cd "$@"; pwd; }

Ps:无论如何，恕我直言，重新定义shell内置程序不是最好的主意.

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