Reset PATH in ~/.bash_profile such that PATH variable follows user-defined order of paths.

reset_path_variable_bash.sh

## add following to the end of ~/.bash_profile assuming ~/.bash_profile takes the precedence over ~/.profile (if present), ~/.bash_profile, or other bash configs.
## for zsh or other shells, you may need to tweak following code.
## Be careful "resetting" PATH variable and know the implications of PATH variable being either empty or missing critical system paths!

################################### SET PATH ###################################
## User specific environment and startup programs
## Rewriting PATH ##
## We want user and anaconda paths to precede system paths, esp. this string:
## /usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin which contains
## most of system default libs,
## i.e., incompatible versions of gcc, g++, and other devtools.
## Make sure to append PATH variable in case sysadmin adds more tools in
## /etc/bashrc. This will duplicate most of path but it doesn't matter as we
## set precedence for user configs in PATH string and include all of PATH
## locations.
## Also note ${PATH:+:$PATH} before system paths. This will force system paths to
## append at the end but module paths to precede system paths.

export deprecPATH=$PATH

## Set PATH based on HPC ##
## Sumner is CPU based and Winter is GPU based HPC at JAX.
if [[ "$(hostname)" == *"sumner"* ]]; then
        PATH="${HOME}/bin:${SUM7ENV}/bin:${HOME}/anaconda3/bin:${HOME}/anaconda3/condabin:${HOME}/.local/bin:${SUM7ENV}/opt/bin:${SUM7ENV}/local/bin:/cm/shared/apps/slurm/current/sbin:/cm/shared/apps/slurm/current/bin${PATH:+:$PATH}:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin"
        MYENV="SUMNER7"
elif [[ "$(hostname)" == *"winter"* ]]; then
        PATH="${HOME}/bin:${SUM7ENV}/bin:${HOME}/anaconda3/envs/tf-gpu/bin:${HOME}/anaconda3/condabin:${HOME}/.local/bin:${HOME}/anaconda3/bin:${SUM7ENV}/opt/bin:${SUM7ENV}/local/bin:/cm/shared/apps/slurm/current/sbin:/cm/shared/apps/slurm/current/bin:${SUM7ENV}/opt/gpu/tensorRT/TensorRT-6.0.1.5/bin${PATH:+:$PATH}:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin"
        MYENV="WINTER7"
else
        PATH="${HOME}/bin:${SUM7ENV}/bin:${HOME}/anaconda3/bin:${HOME}/anaconda3/condabin:${HOME}/.local/bin:${SUM7ENV}/opt/bin:${SUM7ENV}/local/bin:/cm/shared/apps/slurm/current/sbin:/cm/shared/apps/slurm/current/bin${PATH:+:$PATH}:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin"
        MYENV="UNKNOWN"
fi

#### remove duplicate PATH entries BUT preserve order of entries ###
## prefer bash solution
## bash: https://unix.stackexchange.com/a/40973/28675
## perl: https://unix.stackexchange.com/a/50169/28675

if [ -n "$PATH" ]; then
        ## THIS UNSETS PATH - CAREFUL ON CHOICE OF COMMANDS YOU HAVE NOW!
          old_PATH=$PATH:; PATH=
          while [ -n "$old_PATH" ]; do
            x=${old_PATH%%:*}       # the first remaining entry
            case $PATH: in
              *:"$x":*) ;;          # already there
              *) PATH=$PATH:$x;;    # not there yet
            esac
            old_PATH=${old_PATH#*:}
          done
          PATH=${PATH#:}
          unset old_PATH x
fi

export PATH MYENV