Creating a binary package using Cargo

As with any other script, Cargo works (by default) on the current working directory. (For example, while writing this chapter, my working directory for the example code is ~/Developer/Rust/chapter0 on the Mac and Linux boxes, and J:\Developer\Rust\Chapter0 on the Windows 10 machine.)

In its simplest form, Cargo can generate the correct file structure like this:

cargo new demo_app_name -bin 

The preceding command tells Cargo to create a new structure called demo_app_name, and that it is to be a binary. If you remove -bin, it creates a structure called, which is going to be a library (or more accurately, something other than a binary).

If you don't wish to use the root (say you want to create a library within your binary framework), then instead of demo_app_name, you append the structure before the name relating to your working directory.

In the small example I gave earlier, if I wanted to create a library within my binary structure, I would use the following:

cargo new app_name/mylib  

That will create a structure like this:

The Cargo.toml file requires no editing (at this stage), as it contains the information we had to enter manually when we created the project by hand.

Cargo has a number of directory separator translators. This means that the preceding example can be used on OS X, Linux, and Windows without an issue; Cargo has converted the / to \ for Windows.