run `nvm use` automatically every time there's a .nvmrc file on the directory

If you use zsh (z shell):

Calling 'nvm use' automatically in a directory with a .nvmrc file

Put this into your $HOME/.zshrc to call nvm use automatically whenever you enter a directory that contains an .nvmrc file with a string telling nvm which node to use:

# place this after nvm initialization!autoload -U add-zsh-hookload-nvmrc() {  local node_version="$(nvm version)"  local nvmrc_path="$(nvm_find_nvmrc)"  if [ -n "$nvmrc_path" ]; then    local nvmrc_node_version=$(nvm version "$(cat "${nvmrc_path}")")    if [ "$nvmrc_node_version" = "N/A" ]; then      nvm install    elif [ "$nvmrc_node_version" != "$node_version" ]; then      nvm use    fi  elif [ "$node_version" != "$(nvm version default)" ]; then    echo "Reverting to nvm default version"    nvm use default  fi}add-zsh-hook chpwd load-nvmrcload-nvmrc

More info: https://github.com/creationix/nvm#zsh

If you use bash you can add this to your ~/.bashrc file:

enter_directory() {  if [[ $PWD == $PREV_PWD ]]; then    return  fi  PREV_PWD=$PWD  [[ -f ".nvmrc" ]] && nvm use}export PROMPT_COMMAND=enter_directory

Excellent answer from @devius.

I just extended it so it can revert to the default version when leaving a directory with .nvmrc to another without it.

~/.bashrc:

## Run 'nvm use' automatically every time there's # a .nvmrc file in the directory. Also, revert to default # version when entering a directory without .nvmrc#enter_directory() {if [[ $PWD == $PREV_PWD ]]; then    returnfiPREV_PWD=$PWDif [[ -f ".nvmrc" ]]; then    nvm use    NVM_DIRTY=trueelif [[ $NVM_DIRTY = true ]]; then    nvm use default    NVM_DIRTY=falsefi}export PROMPT_COMMAND=enter_directory

Following @doug-barbieri's suggestion, the script below will not change node back to the default version if there's no .nvmrc file in the current directory but there is one in the parent sub-directory.

~/.bashrc:

enter_directory() {  if [[ $PWD == $PREV_PWD ]]; then    return  fi  if [[ "$PWD" =~ "$PREV_PWD" && ! -f ".nvmrc" ]]; then    return  fi  PREV_PWD=$PWD  if [[ -f ".nvmrc" ]]; then    nvm use    NVM_DIRTY=true  elif [[ $NVM_DIRTY = true ]]; then    nvm use default    NVM_DIRTY=false  fi}

The trick is here:

if [[ "$PWD" =~ "$PREV_PWD" && ! -f ".nvmrc" ]]; then  returnfi

It checks if the PWD contains PREV_PWD. For example, if /home/user1/a/b contains /home/user1/a.