A MacOS Trick to Develop Multiple Projects from a Single Command

Introduction

The terminal is one of the most important tools in every developer’s arsenal, but I often find myself typing out the same commands multiple times every day. In particular, I typically spend a minute or two every day setting up development processes for the same four-or-so projects.

This is unnecessary, since it could be automated!

After a bit of research, I realised that — without too much effort — I could create a shortcut to help me spawn multiple terminals, each running a separate development process, from a single keyword. In this article, I’ll share how.

The “open” command

On MacOS, the best way I found was to use the open command. Using the -a flag, we can open a specific app — like the Terminal or iTerm — and pass it a Bash (or Zsh) file to open, which will run immediately. It’s possible to do something similar using AppleScript, but I found the open method simpler.

Creating a shell file for each project

First, we need to create a shell file containing the code we want to run for each of our projects or processes. We can create a new file and with the extension “.sh”, and in it we can put the repetitive shell code we want to automate for a single task.

For me, since I work with Node.js, I will typically navigate to a project, run nvm use to ensure I am running the correct Node version for the project, and then yarn develop.

My files look something like this, and I’ll have one for every project I want to run locally in my standard development process:

#!/bin/zsh

cd ~/work/my-nodejs-project
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
nvm use
yarn develop

At the top of the file, we have a shebang !# followed by code that tells the interpreter how the script to run. This could be Bash, though in this case I’m using Zsh. Next, we cd into my project direction.

The following line is used to tell Zsh to load nvm, which we then run to select the project’s Node.js version. Finally, we run the development command for the project.

I’ll have one of these files for each project, typically with some minor differences based on the steps needed to run the project in development.

Running the shell files in parallel

Now we have created our shell files, we simply need to run them. Using a single ampersand &, we can set these processes off in parallel:

#!/bin/zsh

code ~/work/my-workspace.code-workspace \
& open -a iTerm ~/scripts/develop-my-first-project.sh \
& open -a iTerm ~/scripts/develop-my-second-project.sh \
& open -a iTerm ~/scripts/develop-my-third-project.sh

I use iTerm but any terminal application should work. As part of this command, I also open up a VSCode workspace using the code command. (To set that up, see the official docs). I named the above file develop-projects.sh.

Adding an alias

Finally, we can create an alias to run the above script quickly. The exact way to do this will depend on the shell you use, but for Zsh, go to the .zshrc config file and add something like this:

alias develop="bash ~/scripts/develop-projects.sh"

I hope you found this trick useful. If you’re looking for a similar trick but you’re not using a Mac, I suggest checking out the start command on Windows and the gnome-terminal or xterm commands on Linux.