tmux copy does not work

Question

I'm trying to become more proficient with tmux, but I ran into ( what seems to me ), a weird issue. Here's my tmux.conf:

  1 TERM=screen-256color                                                                                                                                                                                                               
  2 set-option -g default-terminal $TERM                                                                                                                                                                                               
  3                                                                                                                                                                                                                                    
  4 TMUX_COLOUR_BORDER="colour237"                                                                                                                                                                                                     
  5 TMUX_COLOUR_ACTIVE="colour231"                                                                                                                                                                                                     
  6 TMUX_COLOUR_INACTIVE="colour16"                                                                                                                                                                                                    
  7                                                                                                                                                                                                                                    
  8 set-window-option -g window-status-activity-bg $TMUX_COLOUR_BORDER                                                                                                                                                                 
  9 set-window-option -g window-status-activity-fg $TMUX_COLOUR_ACTIVE                                                                                                                                                                 
 10 set-window-option -g window-status-current-format "#[fg=$TMUX_COLOUR_ACTIVE]#I:#W#F"                                                                                                                                               
 11 set-window-option -g window-status-format "#[fg=$TMUX_COLOUR_INACTIVE]#I:#W#F"                                                                                                                                                     
 12                                                                                                                                                                                                                                    
 13                                                                                                                                                                                                                                    
 14 set -g prefix C-a                                                                                                                                                                                                                  
 15                                                                                                                                                                                                                                    
 16 bind-key o split-window -v                                                                                                                                                                                                         
 17 bind-key e split-window -h                                                                                                                                                                                                         
 18                                                                                                                                                                                                                                    
 19 bind-key w kill-pane    

I'm trying to copy paste between two panes. So, I hit Ctrl-a-[ , and then Ctrl-space. The thing is, I don't see a visual selection of the block, and alt-w also does not work ( since I guess it's not even entering copy mode ). Is there an obvious error in my tmux.conf? Can you spot what I'm doing wrong?

Answer 1

tmux has an option, mode-keys, you can find it in man page.

default is emacs, but if your $EDITOR is vim/vi, tmux will use vi.

So the key binding will be in vi mode.

E.g. your Alt-w won't work, it is emacs binding. you can see a table of key-binds in tmux man page.

some related to your question:

Function                     vi              emacs
Copy selection               Enter           M-w
Start selection              Space           C-Space

so you should go with the vi-mode keys.

I used vim mode too, and did a little customization (to make it same as vim) in my tmux.conf, maybe you could give it a try:

bind-key -t vi-copy 'v' begin-selection     # Begin selection in copy mode.
bind-key -t vi-copy 'C-v' rectangle-toggle  # Begin selection in copy mode.
bind-key -t vi-copy 'y' copy-selection      # Yank selection in copy mode.

Answer 2

In case it helps, I had a correct tmux configuration (with vi like settings for selection & copy/paste) but needed to set these two environment variables in my .zshrc file (using Zsh & Neovim):

export EDITOR='nvim'
export VISUAL='nvim'