Installation

To use jbang Java 8 is the minimum required version, however Java 11 or higher is recommended.

Note: jbang will download and install java from Adopt OpenJDK if no java is available.

There are multiple ways to install jbang. See below for all available options.

Once you have jbang installed, it is recommended you run jbang app setup. This script will make the following changes to your system:

  1. Modify PATH environment variable to include jbang app scripts

  2. For supported shells, add j! as an alias for jbang. Try running j! version to verify.

By default jbang uses ~/.jbang for configurations and build cache. This can be changed using the environment variable JBANG_DIR.

Using JBang

The simplest way to install jbang is using JBang itself. This method has no other requirements (besides curl on Linux/OSX/AIX).

Linux/OSX/Windows/AIX Bash:

curl -Ls https://sh.jbang.dev | bash -s - app setup

Windows Powershell:

iex "& { $(iwr -useb https://ps.jbang.dev) } app setup"

SDKMan /

Although if you want to have easy updates or install multiple JBang versions we recommend sdkman to install both java and jbang on Linux and OSX.

curl -s "https://get.sdkman.io" | bash (1)
source ~/.bash_profile (2)

sdk install java (3)

Once Java is installed and ready, you install jbang with

sdk install jbang

To test your installation run:

jbang --help

This should print out usage information.

To update run:

sdk upgrade jbang

Chocolatey

On Windows you can install both java and jbang with Chocolatey.

From a command prompt with enough rights to install with choco:

choco install jdk11

Once Java in installed run:

choco install jbang

To upgrade to latest version:

choco upgrade jbang

The latest package will be published to jbang choco package page, it might be a bit delayed as the review is still manual. In case the default version is not the latest you can see the version list and install specific version using:

choco install jbang --version=<version number>

Scoop

On Windows you can also install jbang with Scoop.

scoop bucket add jbangdev https://github.com/jbangdev/scoop-bucket
scoop install jbang

To upgrade to latest version:

scoop update jbang

Homebrew

On OSX you can install 'java' and jbang with Homebrew using custom taps.

To install Java 11:

brew tap AdoptOpenJDK/openjdk
brew install adoptopenjdk11 --cask

Once Java is installed you can use brew with jbangdev/tap to get jbang:

brew install jbangdev/tap/jbang

To upgrade to latest version:

brew upgrade jbangdev/tap/jbang

(Experimental) Linux packages

These builds are not fully automated yet thus might be slightly behind.

You can install rpm packages from Fedora Copr by doing the following:

dnf copr enable @jbangdev/jbang
dnf install jbang

The COPR currently includes builds from various versions of CentOS, Fedora, Mageia and OpenSuse.

Docker / GitHub Action

You can run jbang via Docker:

docker run -v `pwd`:/ws --workdir=/ws -ti jbangdev/jbang-action helloworld.java

or if you prefer using Quay.io:

docker run -v `pwd`:/ws --workdir=/ws -ti quay.io/jbangdev/jbang-action helloworld.java

The same container images can be used with GitHub Actions, see jbang-action for details.

Remember to remove -ti from the commands above when using on a GitHub Actions flow.

Maven Plugin

The JBang Maven plugin allows JBang scripts to be executed during a Maven build.

Example in your pom.xml:

      <plugin>
        <groupId>dev.jbang</groupId>
        <artifactId>jbang-maven-plugin</artifactId>
        <version>0.0.7</version>
        <executions>
          <execution>
            <id>run</id>
            <phase>process-resources</phase>
            <goals>
              <goal>run</goal>
            </goals>
            <configuration>
                <script>hello.java</script>
            </configuration>
          </execution>
        </executions>
      </plugin>

The plugin documentation and more examples are available here: https://github.com/jbangdev/jbang-maven-plugin

Gradle Plugin

The JBang Gradle plugin allows JBang scripts to be executed during a Gradle build.

In your build.gradle file, add:

plugins {
    id 'dev.jbang' version '0.2.0'
}

That will allow you to execute JBang scripts with:

$ gradle jbang --jbang-script hello.jsh --jbang-args="Hello world"

The plugin documentation and more examples are available here: https://github.com/jbangdev/jbang-gradle-plugin

Manual install

Unzip the latest binary release, add the jbang-<version>/bin folder to your $PATH and you are set.

Wrapper install

If you would like to have jbang available in a local directory and committed into a source code repository (akin to Maven and Gradle wrappers) you can use the jbang wrapper command.

If you have jbang already installed you call jbang wrapper install in a folder to install a local jbang that will run out of that directory using ./jbang.

The ./.jbang directory which jbang wrapper install creates is just a cache which you typically would not commit to a source code repository, so you can e.g. echo .jbang/ >>.gitignore.

"Zero" Install

If you want to try out jbang without a package manager or similar you can run the following to download jbang in ~/.jbang and if necessary java.

Linux/OSX/Windows/AIX Bash:

curl -Ls https://sh.jbang.dev | bash -s - <arguments>

For example curl -Ls https://sh.jbang.dev | bash -s - properties@jbangdev

Windows Powershell:

iex "& { $(iwr -useb https://ps.jbang.dev) } <arguments>"

For example iex "& { $(iwr -useb https://ps.jbang.dev) } properties@jbangdev"

Version check

jbang will check once a day if a new version is available. If a new version is available a message will be printed with information on how to install.

The check happens in the background and will only be done every 24hrs on the same installation.

The version check is done via a HTTP request to fetch a version.txt from https://jbang.dev. The request includes a user-agent that contains the current jbang, java and operating system version with no person identifiable information which we use purely to aggregate statistics to know update/usage frequency.

jbang will not do its automatic check for version when you run in --offline mode nor if you set JBANG_NO_VERSION_CHECK environment variable.

Example:

jbang test.java ## if more than 24hrs last check version will be checked
export JBANG_NO_VERSION_CHECK
jbang test.java ## no version check made as JBANG_NO_VERSION_CHECK is set