brew/Library/Homebrew/cmd/shellenv.sh

#:  * `shellenv`
#:
#:  Prints export statements - run them in a shell and this installation of Homebrew will be included into your `PATH`, `MANPATH` and `INFOPATH`.
#:
#:  `HOMEBREW_PREFIX`, `HOMEBREW_CELLAR` and `HOMEBREW_REPOSITORY` are also exported to save multiple queries of those variables.
#:
#:  Consider adding evaluating the output in your dotfiles (e.g. `~/.profile`) with `eval $(brew shellenv)`

homebrew-shellenv() {
  echo "export HOMEBREW_PREFIX=\"$HOMEBREW_PREFIX\""
  echo "export HOMEBREW_CELLAR=\"$HOMEBREW_CELLAR\""
  echo "export HOMEBREW_REPOSITORY=\"$HOMEBREW_REPOSITORY\""
  echo "export PATH=\"$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:\$PATH\""
  echo "export MANPATH=\"$HOMEBREW_PREFIX/share/man:\$MANPATH\""
  echo "export INFOPATH=\"$HOMEBREW_PREFIX/share/info:\$INFOPATH\""
}