Ranger file manager as the singleton instance on shell startup

Question

Problem:
I use zsh and added to its config file a line of launching ranger on startup.

.zshrc

# A few other settings and commands.
ZSH_TMUX_AUTOSTART="true"
plugins=(tmux ...)

source ranger

Due to it every newly opened(mostly in tmux) zsh runs ranger.

Expectation:
Lauch a ranger process only if there is no running one.

Something like looks as follow:

if [[ ! -v RANGER_RUNNIG ]]; then
   export RANGER_RUNNING="true"
   source ranger
fi

Answer 1

Basically, the solution through modifying what zsh does on every new shell sounds a bit complicated. Instead, simply start your tmux with the program that you want to show in the first pane:

tmux new-session ranger

When you manually add further panes, they will just start the default shell.

You can also prepare a whole bunch of panes. For example, to start with a layout of

┌────────────┬───────────┐
│            │    zsh    │
│            │           │
│  ranger    ├───────────┤
│            │    zsh    │
│            │           │
└────────────┴───────────┘

you could just

#!/bin/sh
# e.g. /usr/local/bin/my_tmux
# or just ~/bin/mt, to make your typing easier 
# (assuming /home/r45i/bin is part of $PATH)
#

# check we're not running within tmux
if [ -z "$TMUX" ]
then
  # start a detached session
  tmux new-session -d ranger
  # split the window horizontally
  tmux split-window -h
  # split the freshly created vertically
  tmux split-window -v
  # attach to the session
  tmux attach-session -d
fi