tmux.conf

bind p paste-buffer
bind C-p choose-buffer

# Version-specific commands [grumble, grumble]
# See: https://github.com/tmux/tmux/blob/master/CHANGES
run-shell "tmux setenv -g TMUX_VERSION $(tmux -V | cut -c 6-)"

if-shell -b '[ "$(echo "$TMUX_VERSION < 2.1" | bc)" = 1 ]' \
  "set -g mouse-select-pane on; set -g mode-mouse on; \
   set -g mouse-resize-pane on; set -g mouse-select-window on; \
   bind m \
    set -g mode-mouse on \\\; set -g mouse-resize-pane on \\\;\
    set -g mouse-select-pane on \\\; set -g mouse-select-window on \\\;\
    display 'Mouse: ON'; \
   bind M \
    set -g mode-mouse off \\\; set -g mouse-resize-pane off \\\;\
    set -g mouse-select-pane off \\\; set -g mouse-select-window off \\\;\
    display 'Mouse: OFF'"

# In version 2.1 "mouse" replaced the previous 4 mouse options
if-shell -b '[ "$(echo "$TMUX_VERSION >= 2.1" | bc)" = 1 ]' \
  "set -g mouse on; \
   bind M set -g mouse off \\\; display 'Mouse OFF'; \
   bind m set -g mouse on \\\; display 'Mouse ON'" 

# UTF8 is autodetected in 2.2 onwards, but errors if explicitly set
if-shell -b '[ "$(echo "$TMUX_VERSION < 2.2" | bc)" = 1 ]' \
  "set -g utf8 on; set -g status-utf8 on; set -g mouse-utf8 on"

# bind-key syntax changed in 2.4
if-shell -b '[ "$(echo "$TMUX_VERSION < 2.4" | bc)" = 1 ]' \
  "bind-key -t vi-copy v   begin-selection; \
   bind-key -t vi-copy V   select-line; \
   bind-key -t vi-copy C-v rectangle-toggle; \
   bind-key -t vi-copy y   copy-pipe 'xclip -selection clipboard -in'"

# Newer versions
if-shell -b '[ "$(echo "$TMUX_VERSION >= 2.4" | bc)" = 1 ]' \
  "bind-key -T copy-mode-vi v   send -X begin-selection; \
   bind-key -T copy-mode-vi V   send -X select-line; \
   bind-key -T copy-mode-vi C-v send -X rectangle-toggle; \
   bind-key -T copy-mode-vi y   send -X copy-pipe-and-cancel 'xclip -selection clipboard -in'"