Change the path of the main shell after executing cd in a shell script.

Background#

Last night, I wanted to use fzf in conjunction with cd, which means passing the result of fzf to cd to execute, so I came up with this command:

cd $(fd --type d | fzf)

This command can indeed accomplish the task, but there are two problems:

If you exit directly, you will return to the home directory because the execution result of $(..) is empty.
It is cumbersome to enter so much every time.

Using alias#

Then I tried using an alias, so I added the following to .zshrc:

alias cdf="cd $(fd --type d | fzf)"

The result is that it cannot be executed directly because it directly recognizes the $(..) part and executes it, but the rest will not be executed.

Using a shell script#

Then I wrote this file:

#!/bin/sh
path=$(fd --type d --strip-cwd-prefix --hidden --follow --exclude .git --exclude node_modules | fzf)

if [ -z "$path" ]; then
    exit
fi

cd "$path" || exit

The result is also not working. I added a line echo "$PWD" at the bottom, and I saw that it was executed, but it became ineffective after the program exited.

Solution#

Finally, I found that I can use source xxx or . xxx to solve it. In the end, I used alias+shell script to complete this operation:

alias cdf="source /path/to/cdf"

At the same time, it also solves the two problems mentioned above.

Why can source solve it?#

The reason why running the shell script directly doesn't work is because it is not running in the current shell environment, but in a subshell, so the result cannot change the current file directory.

However, source or . represents executing in the current shell environment, so it can succeed.

Update#

2022/11/18#

Today I discovered an easier solution, which is to write a shell function:

function cd() {
    cd "$(fzf)"
}

Add it to .zshrc (I'm using zsh), and then enter cd in the command line.