Dynamically build PATH variable with a function that can also be used to append to the PATH

set_env_path

# A function to update the PATH variable
# shellcheck disable=SC2120
set_env_path() {
  local path dir newPath
  
  # If we have any args, feed them into ~/.pathrc
  if (( "${#}" > 0 )); then
    # shellcheck disable=SC2048
    for path in ${*}; do
      if [[ -d "${path}" ]]; then
        if ! grep -q "${path}" "${HOME}"/.pathrc; then
          printf -- '%s\n' "${path}" >> "${HOME}"/.pathrc
        fi
      fi
    done
  fi

  # Open an array of potential PATH members, including Solaris bin/sbin paths
  pathArray=(
    /usr/gnu/bin /usr/xpg6/bin /usr/xpg4/bin /usr/kerberos/bin \
    /usr/kerberos/sbin /bin /sbin /usr/bin /usr/sbin /usr/local/bin \
    /usr/local/sbin /usr/local/opt/texinfo/bin /usr/local/opt/libxml2/bin \
    /usr/X11/bin /opt/csw/bin /opt/csw/sbin /opt/sfw/bin /opt/sfw/sbin \
    /opt/X11/bin /usr/sfw/bin /usr/sfw/sbin /usr/games /usr/local/games \
    /snap/bin "${HOME}"/bin "${HOME}"/go/bin /usr/local/go/bin \
    "${HOME}"/.cargo /Library/TeX/texbin "${HOME}"/.fzf/bin \
    /usr/local/opt/fzf/bin
  )
 
  # If Android Home exists, add more dirs
  if [[ -d "${HOME}"/Library/Android/sdk ]]; then
    export ANDROID_HOME="${HOME}"/Library/Android/sdk
    pathArray+=( "${ANDROID_HOME}"/tools )
    pathArray+=( "${ANDROID_HOME}"/tools/bin )
    pathArray+=( "${ANDROID_HOME}"/emulator )
    pathArray+=( "${ANDROID_HOME}"/platform-tools )
  fi    
  
  # Add anything from .pathrc, /etc/paths and /etc/paths.d/*
  # i.e. OSX, because path_helper can be slow...
  while read -r; do
    pathArray+=( "${REPLY}" )
  done < <(cat "$(find "${HOME}"/.pathrc /etc/paths /etc/paths.d -type f 2>/dev/null)" 2>/dev/null)

  # Iterate through the array and build the newPath variable using found paths
  newPath=
  for dir in "${pathArray[@]}"; do
    # If it's already in newPath, skip on to the next dir
    case "${newPath}" in 
      (*:${dir}:*|*:${dir}$) continue ;; 
    esac
    [[ -d "${dir}" ]] && newPath="${newPath}:${dir}"
  done

  # Now assign our freshly built newPath variable, removing any leading colon
  PATH="${newPath#:}"

  # Finally, export the PATH
  export PATH
}

# Run the function to straighten out PATH
# shellcheck disable=SC2119
set_env_path