Building Linux apps with Flutter

This page discusses considerations unique to building Linux apps with Flutter, including shell integration and preparation of apps for distribution.

Integrating with Linux

The Linux programming interface, comprising library functions and system calls, is designed around the C language and ABI. Fortunately, Dart provides dart:ffi, which is designed to enable Dart programs to efficiently call into C libraries. FFI provides Flutter apps with the ability to allocate native memory with malloc or calloc, support for pointers, structs and callbacks, and ABI types like long and size_t.

For more information about calling C libraries from Flutter, see C interop using dart:ffi.

Many apps will benefit from using a package that wraps the underlying library calls in a more convenient, idiomatic Dart API. Canonical has built a series of packages with a focus on enabling Dart and Flutter on Linux, including support for desktop notifications, dbus, network management, and Bluetooth.

More generally, many other packages support Linux, including common packages such as url_launcher, shared_preferences, file_selector, and path_provider.

Preparing Linux apps for distribution

The executable binary can be found in your project under build/linux/<build mode>/bundle/. Alongside your executable binary in the bundle directory there are two directories:

• lib contains the required .so library files
• data contains the application’s data assets, such as fonts or images

In addition to these files, your application also relies on various operating system libraries that it’s been compiled against. You can see the full list by running ldd against your application. For example, assuming you have a Flutter desktop application called linux_desktop_test, you could inspect the system libraries it depends upon as follows:

$ flutter build linux --release
$ ldd build/linux/release/bundle/linux_desktop_test

To wrap up this application for distribution you need to include everything in the bundle directory, and make sure the Linux system you are installing it on has all of the system libraries required. This may be as simple as:

$ sudo apt-get install libgtk-3-0 libblkid1 liblzma5

For information on publishing a Linux application to the Snap Store, see Build and release a Linux application to the Snap Store.