An alternative solution to direnv dropping aliases and functions

Sun, 12 Oct 2025 00:00:00 +0000

Direnv’s inability to export shell-specific aliases and functions, due to its shell-agnostic design, can be addressed in Nix by using pkgs.writeScriptBin to create executable scripts instead.

Manipulating Directories - Shell Builtins cd pushd and popd

Thu, 04 Sep 2025 00:00:00 +0000

大多数现代 shell 有一系列 shell builtins（例：zsh ），其中一些可以用来操作目录。

为了操作目录，在内存中维护了一个目录栈结构。在 bash 中也可以通过 $DIRSTACK shell variable 访问到。bash 的目录栈介绍页，zsh 的目录栈介绍页

通过 pushd 和 popd，可以进入一系列目录并且按反序退出。

[1:cuso4d@nightcord-laborari:~]
$ pwd
/home/cuso4d
[1:cuso4d@nightcord-laborari:~]
$ pushd ~/source/zsh
~/source/zsh ~
[1:cuso4d@nightcord-laborari:~/source/zsh on master]
$ pushd ~/.ssh
~/.ssh ~/source/zsh ~
[1:cuso4d@nightcord-laborari:~/.ssh]
$ popd
~/source/zsh ~
[1:cuso4d@nightcord-laborari:~/source/zsh on master]
$ popd
~
[1:cuso4d@nightcord-laborari:~]
$ pwd
/home/cuso4d

以 zsh 为例子，目录栈是使用链表实现的。位置在 Src/Bulitin.c。

static struct builtin builtins[] =
{
	// ...
	BUILTIN("cd", BINF_SKIPINVALID | BINF_SKIPDASH | BINF_DASHDASHVALID, bin_cd, 0, 2, BIN_CD, "qsPL", NULL),
 BUILTIN("popd", BINF_SKIPINVALID | BINF_SKIPDASH | BINF_DASHDASHVALID, bin_cd, 0, 1, BIN_POPD, "q", NULL),
 BUILTIN("pushd", BINF_SKIPINVALID | BINF_SKIPDASH | BINF_DASHDASHVALID, bin_cd, 0, 2, BIN_PUSHD, "qsPL", NULL),
 // ...
}

BUILTIN 宏的阅读方法

Shell on CuSO4_Deposit

An alternative solution to direnv dropping aliases and functions

Manipulating Directories - Shell Builtins cd pushd and popd