How do I access the alternate file register?

Explanation

The # register contains the name of the alternate file — the previously edited file in the current window. You can use it in commands and paste it.

How it works

• "# stores the alternate filename
• "#p pastes the alternate filename
• <C-r># inserts it in insert/command mode
• <C-^> switches to the alternate file

Example

While editing main.go after previously editing utils.go, "#p inserts utils.go.

Tips

• :e # opens the alternate file
• :ls shows # next to the alternate buffer
• Useful in scripts and mappings that reference the previous file
• <C-^> is the fastest way to toggle between two files
• The alternate file is set when you switch buffers