How do I detect whether a macro is currently being recorded or executed in Vimscript?

Explanation

Vim exposes two built-in functions for querying the current macro state: reg_recording() and reg_executing(). Both return the register letter currently in use, or an empty string when no macro is active. These unlock a class of context-aware behavior — from real-time statusline indicators to mappings that change behavior mid-recording.

How it works

• reg_recording() — returns the register letter while q{reg} is active (recording); returns '' otherwise
• reg_executing() — returns the register letter while @{reg} is running (executing); returns '' otherwise
• Both can be combined: reg_recording() . reg_executing() gives the union of active macro state

Example

Add a recording indicator to your statusline so you always know when you're mid-macro:

set statusline+=%{reg_recording()!=''?'[REC @'.reg_recording().']':''}

With this, the statusline shows [REC @q] the moment you press qq, and clears automatically when you press q to stop.

For a mapping that skips an action during macro execution:

nnoremap <expr> <F5> reg_executing() == '' ? ':make<CR>' : ''

This prevents :make from firing if <F5> is embedded in a macro being replayed.

Tips

• Neovim users can also hook into RecordingEnter / RecordingLeave autocmd events (Neovim 0.8+) for event-driven alternatives
• mode(1) returns 'R' during Ex recording but does not distinguish which register; reg_recording() is more precise
• These functions work inside statusline, tabline, and <expr> mappings — anywhere an expression is evaluated