Linux - How to work with complex commands

It can frustrate to work on complex commands in the terminal. I’ll present you some tips on how to manage them. If you have another tip, I’d appreciate a quick message.

Use backslash\ to add a line break

This is fairly simple. Having one or multiple long lines with no structure can be messy and confusing. By adding \ for a line break adds more structure. A really simple example:

podman run -d --restart=always -p 127.0.0.1:3001:3001 -v /path/data:/app/data --name status.brrl.net docker.io/louislam/uptime-kuma:latest

With line breaks:

podman run -d \
  --restart=always \
  -p 127.0.0.1:3001:3001 \
  -v /path/data:/app/data \
  --name status.brrl.net \
  docker.io/louislam/uptime-kuma:latest

It is easier to read and work with, at least in my opinion.

Work on complex commands in your favorite $EDITOR

I’lll show you now, how you can edit complex commands in your favorite CLI editor.

Enter command fc, or keep CTRL pressed and enter x and e as keyboard shortcut. This will open your default CLI editor. After finishing working on the command you want to run, simply ‘save and close’, and the command will run right after. I am going to show you how yo set your default editor at the end of the post.

The fc command is normally used to show the command history or re-edit already entered commands, but we can use it to work on complex commands. fc --help to find out more.

Set default editor in the CLI

There are various ways to set the default editors, so you might have to look it up for your setup.

In general, it works to set the $EDITOR environment variable with the editor of choice. On most distros it should be ‘nano’, but you might prefer something else.

If we want to change our default editor to ‘vim’ temporarily, we can enter this command:

export EDITOR="/bin/vim"

You can double-check with:

echo $EDITOR or env | grep EDITOR

and

$EDITOR test.txt

Important: To change the default editor permanently, add export EDITOR="/bin/vim" to your .bashrc or whatever config file you use.

From now on, whenever you want to edit a command with fc, your favorite editor will open.