1. Interactive mode

Interactive mode 

Use tab completion 

By default, sbt’s interactive mode is started when no commands are provided on the command line or when the shell command is invoked.

As the name suggests, tab completion is invoked by hitting the tab key. Suggestions are provided that can complete the text entered to the left of the current cursor position. Any part of the suggestion that is unambiguous is automatically appended to the current text. Commands typically support tab completion for most of their syntax.

As an example, entering tes and hitting tab:

> tes<TAB>

results in sbt appending a t:

> test

To get further completions, hit tab again:

> test<TAB>
testFrameworks   testListeners    testLoader       testOnly         testOptions      test:

Now, there is more than one possibility for the next character, so sbt prints the available options. We will select testOnly and get more suggestions by entering the rest of the command and hitting tab twice:

> testOnly<TAB><TAB>
--                      sbt.DagSpecification    sbt.EmptyRelationTest   sbt.KeyTest             sbt.RelationTest        sbt.SettingsTest

The first tab inserts an unambiguous space and the second suggests names of tests to run. The suggestion of -- is for the separator between test names and options provided to the test framework. The other suggestions are names of test classes for one of sbt’s modules. Test name suggestions require tests to be compiled first. If tests have been added, renamed, or removed since the last test compilation, the completions will be out of date until another successful compile.

Show more tab completion suggestions 

Some commands have different levels of completion. Hitting tab multiple times increases the verbosity of completions. (Presently, this feature is only used by the set command.)

Modify the default JLine keybindings 

JLine, used by both Scala and sbt, uses a configuration file for many of its keybindings. The location of this file can be changed with the system property jline.keybindings. The default keybindings file is included in the sbt launcher and may be used as a starting point for customization.

Configure the prompt string 

By default, sbt only displays > to prompt for a command. This can be changed through the shellPrompt setting, which has type State => String. State contains all state for sbt and thus provides access to all build information for use in the prompt string.

Examples:

// set the prompt (for this build) to include the project id.
ThisBuild / shellPrompt := { state => Project.extract(state).currentRef.project + "> " }

// set the prompt (for the current project) to include the username
shellPrompt := { state => System.getProperty("user.name") + "> " }

Use history 

See sbt shell history.

Change the location of the interactive history file 

By default, interactive history is stored in the target/ directory for the current project (but is not removed by a clean). History is thus separate for each subproject. The location can be changed with the historyPath setting, which has type Option[File]. For example, history can be stored in the root directory for the project instead of the output directory:

historyPath := Some(baseDirectory.value / ".history")

The history path needs to be set for each project, since sbt will use the value of historyPath for the current project (as selected by the project command).

Use the same history for all projects 

The previous section describes how to configure the location of the history file. This setting can be used to share the interactive history among all projects in a build instead of using a different history for each project. The way this is done is to set historyPath to be the same file, such as a file in the root project’s target/ directory:

historyPath :=
  Some( (target in LocalRootProject).value / ".history")

The in LocalRootProject part means to get the output directory for the root project for the build.

Disable interactive history 

If, for whatever reason, you want to disable history, set historyPath to None in each project it should be disabled in:

> historyPath := None

Run commands before entering interactive mode 

Interactive mode is implemented by the shell command. By default, the shell command is run if no commands are provided to sbt on the command line. To run commands before entering interactive mode, specify them on the command line followed by shell. For example,

$ sbt clean compile shell

This runs clean and then compile before entering the interactive prompt. If either clean or compile fails, sbt will exit without going to the prompt. To enter the prompt whether or not these initial commands succeed, prepend "onFailure shell", which means to run shell if any command fails. For example,

$ sbt "onFailure shell" clean compile shell