how to install tmux locally without root access?

You will have to manually install it from source in your home directory and then add that to your path.

The process is straightforward enough and described in a few places, there is a script for V1.8 and a guide for V2.2. I would handrail off both but change everything to the latest version.

These scripts didn't work for me out the box, on step 6a, for version 6.0 nucrses I needed to use the command ./configure --prefix=$HOME/local CPPFLAGS="-P" instead of just ./configure --prefix=$HOME/local as per.

In summary, the process is:

1. Make a temporary folder to work in
2. Download the latest version of tmux. Follow the links to the dependencies and download those into your tempory directory.
3. Setup a local library folder ($HOME/local)
4. Setup a local binaries folder ($HOME/local/bin)
5. extract the files (tar xvzf)
6. Then for dependancies first and finnaly tmux:
   • configure (./configure --prefix=$HOME/local)
   • make
   • make install
7. preappend to path (add this to .bashrc export PATH=$HOME/local/bin:$PATH)

An alternative solution is to install miniconda (no sudo needed) via

$ wget https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh
$ bash Miniconda3-latest-Linux-x86_64.sh

and then install tmux

$ conda install -c conda-forge tmux

also get a bonus htop

$ conda install -c conda-forge htop