为Crontab指定编辑器 | Baeldung中文网

1. Overview

Cron expressions are a useful tool for automating tasks using cron expressions. In this tutorial, we’ll learn how to change the default editor for maintaining our crontab.

2. Environment Variables

There are two environment variables we can use to change the editor opened by crontab -e.

Note that the examples below will change the editor for the current terminal session only. We can make this change persistent by using environment variables.

2.1. EDITOR

First, we can use EDITOR. Let’s change our editor to nano:

$ export EDITOR=/usr/bin/nano

Depending on our configuration, this might not actually work because there is another variable that takes precedence.

2.2. VISUAL

The VISUAL environment variable takes precedence to EDITOR. Let’s see if we can override the EDITOR variable we set before by setting VISUAL to joe:

$ export VISUAL=/usr/bin/joe

Now, every time we issue crontab -e, it should open our crontab in joe instead of nano.

3. select-editor

Some Linux distributions (like Ubuntu) provide us with a command select-editor. Running select-editor gives us a list of editors to choose from:

$ select-editor

Select an editor.  To change later, run 'select-editor'.
  1. /bin/nano        <---- easiest
  2. /usr/bin/vim.basic
  3. /usr/bin/vim.tiny
  4. /bin/ed

Choose 1-4 [1]:

The selection is stored in our home directory in ~/.selected-editor and therefore persistent across terminal sessions.

Note that the environment variables EDITOR and VISUAL take precedence over select-editor, so we’ve got to make sure these variables aren’t set.

4. Conclusion

In this article, we’ve learned how to make crontab -e use our favorite editor. The recommended way is by setting the VISUAL environment variable.

Depending on our Linux distribution, we might also use the select-editor utility.

Persistence

REST