Lazy load nvm for faster shell start

NVM is a version manager for node that makes using specific versions of Node a breeze. I prefer to use it on my development machine instead of system wide node as it gives much more control with almost no added complexity.

Once you install it, it adds the following snippet to your .bashrc:

export NVM_DIR="/Users/zaro/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"  # This loads nvm

and everything just works :)

Except that on my laptop this adds 1-2 seconds of start up time to each new shell I open. It's a bit of annoyance and I don't need it in every terminal session I start, so I thought maybe there will be a way to load it on demand.

After fiddling a bit with it I replaced the NVM snippet with the following:

nvm() {
    unset -f nvm
    export NVM_DIR=~/.nvm
    [ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"  # This loads nvm
    nvm "$@"
}
 
node() {
    unset -f node
    export NVM_DIR=~/.nvm
    [ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"  # This loads nvm
    node "$@"
}
 
npm() {
    unset -f npm
    export NVM_DIR=~/.nvm
    [ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"  # This loads nvm
    npm "$@"
}

Now nvm, node and npm are loaded on their first invocation, posing no start up time penalty for the shells that aren't going to use them at all.

Edit: Thanks to jonknapp's suggestion, now the snippet is more copy paste friendly.

Edit: fl0w_io made a standalone script out of it to include in .bashrc

Edit: sscotth made a version that will register all your globally installed modules

July 18, 2016