ZSH:从使用相同名称的 zsh 函数调用内置函数 [英] ZSH: Call in-built function from zsh function that uses the same name

问题描述

我使用 zsh 并希望稍微扩展内置的 cd 功能.我希望当我调用cd时，它直接改变，然后列出目录的内容.

I use zsh and would like to slightly extend the in-built cd function. I'd like that when I call cd, it changes directly and then lists the content of the directory.

function cd() {
    cd $1
    ls .
}

我原以为这段代码可以工作，但事实证明，对 cd 的调用引用了函数定义，从而导致了无限循环.

I'd have expected this code to work, but as it turns out, the call to cd refers to the function definition, resulting in an infinite loop.

除了为我的函数选择不同的名称外，是否有解决此问题的方法?

Is there a work-around to solve this problem, apart from choosing a different name for my function?

更新

奇怪的是，这奏效了

function cd() {
    `echo $1`
    ls .
}

不知道为什么.

推荐答案

为了在同名函数内或其他任何地方使用内置命令，您可以使用 builtin前置命令修饰符:

In order to use builtin commands from within functions of the same name, or anywhere else for that matter, you can use the builtin precommand modifier:

function cd() {
    builtin cd $1
    ls .
}

builtin COMMAND 告诉 zsh 使用名称为 COMMAND 的内置命令，而不是同名的别名、函数或外部命令.如果这样的内置函数不存在，则会打印一条错误消息.

builtin COMMAND tells zsh to use the builtin with the name COMMAND instead of a alias, function or external command of the same name. If such a builtin does not exist an error message will be printed.

对于要使用外部命令而不是别名、内置命令或同名函数的情况，可以使用 command 前置命令修饰符.例如:

For cases where you want to use an external command instead of an alias, builtin or function of the same name, you can use the command precommand modifier. For example:

command echo foobar

这将使用二进制 echo(很可能是 /bin/echo)而不是 zsh 的 内置 echo.

This will use the binary echo (most likely /bin/echo) instead of zsh's builtin echo.

与函数不同，builtin 和 command 通常不需要别名来防止递归.虽然可以在别名定义中使用别名

Unlike with functions builtin and command are usually not necessary with aliases to prevent recursions. While it is possible to use an alias in an alias definition

% alias xx="echo x:"
% alias yy="xx y:"
% yy foobar
y: x: foobar

每个别名只会扩展一次.第二次出现时，别名不会被扩展，而是会使用函数、内置或外部命令.

each alias name will only expanded once. On the second occurence the alias will not be expanded and a function, builtin or external command will be used.

% alias echo="echo echo:"
% echo foobar
echo: foobar
% alias xx="yy x:"
% alias yy="xx y:"
% xx foobar
zsh: command not found: xx

当然，如果你想阻止使用另一个别名，或者你想使用一个内置或具体的外部命令.例如:

Of course, you can still use builtin or command in aliases, if you want to prevent the use of another alias, or if you want to use a builtin or external command specifically. For example:

alias echo="command echo"

有了这个，二进制 echo 将被用来代替内置的.

With this the binary echo will be used instead of the builtin.

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