This assumes you have installed Sails. The sails new command can be used to install an app into your present working directory. In this example, an app named foo-app will be installed.

sails new foo-app

When prompted to choose a template, it usually makes sense to select Web App.

Choose a template for your new Sails app:
 1. Web App  ·  Extensible project with auth, login, & password recovery
 2. Empty    ·  An empty Sails app, yours to configure
 (type "?" for help, or <CTRL+C> to cancel)
?

Or, if you do not want an interactive prompt, echo 1 can be used to create a Web App.

echo 1 | sails new foo-app

Or echo 1 can be used to create an Empty app.

echo 2 | sails new foo-app

If the app was successfully created, something like this should be returned.

info: Created a new Sails app `foo-app`!

And there should be a directory for the app that contains files and directories.

~]# ls -l foo-app/
drwxr-xr-x.   8 root root    100 Jul 21 22:58 api
-rw-r--r--.   1 root root   1841 Jul 21 22:58 app.js
drwxr-xr-x.   8 root root    130 Jul 21 22:58 assets
drwxr-xr-x.   4 root root   4096 Jul 21 22:58 config
-rw-r--r--.   1 root root    669 Jul 21 22:58 Gruntfile.js
drwxr-xr-x. 512 root root  16384 Jul 21 22:58 node_modules
-rw-r--r--.   1 root root   6133 Jul 21 22:58 package.json
-rw-r--r--.   1 root root 369612 Jul 21 22:58 package-lock.json
-rw-r--r--.   1 root root   1720 Jul 21 22:58 README.md
drwxr-xr-x.   2 root root     34 Jul 21 22:58 scripts
drwxr-xr-x.   4 root root     55 Jul 21 22:58 tasks
drwxr-xr-x.   5 root root    110 Jul 21 22:58 views

The --no-frontend flag can be used to create an app without a front end.

sails new bar-app --no-frontend

Likewise, the --minimal flag can be used to create a minimal app.

sails new bar-app --minimal

In these scenarioa, the bar-app directory should contain the following files and directories.

~]# ls -l bar-app/
drwxr-xr-x.   8 root root    100 Jul 21 22:58 api
-rw-r--r--.   1 root root   1841 Jul 21 22:58 app.js
drwxr-xr-x.   4 root root   4096 Jul 21 22:58 config
drwxr-xr-x. 512 root root  16384 Jul 21 22:58 node_modules
-rw-r--r--.   1 root root   6133 Jul 21 22:58 package.json
-rw-r--r--.   1 root root 369612 Jul 21 22:58 package-lock.json
-rw-r--r--.   1 root root   1720 Jul 21 22:58 README.md