path-install can help you adding a new PATH to .bash_profile and /etc/profile.d/ .
$ gem install path-install
(you may need to run as root or through sudo.)
$ path-install file or directory...
$ path-install /usr/local/ruby2.5.1/bin | tee -a ~/.bash_profile
export PATH=/usr/local/ruby2.5.1/bin:$PATH
$ path-install /usr/local/ruby2.5.1/bin/ruby | sudo tee -a /etc/profile.d/ruby.sh
test -x /usr/local/ruby2.5.1/bin/ruby && \
export PATH=/usr/local/ruby2.5.1/bin:$PATH
Bug reports and pull requests are welcome on GitHub at https://github.com/s3fxn/path-install.
The gem is available as open source under the terms of the MIT License.