Environment Variables

An environment variable is a persistent variable (i.e., key=value pair) in your terminal which becomes available to all commands you execute at the prompt. This facility allows the behavior of commands to be altered based on which environment they are running in. For example, you may use an environment variable in a continuous integration (CI) or publishing environment to enable a behavior which may not be enabled by default.

You can output the current value of an environment variable using the echo command. In a Linux or macOS terminal, type:

In the Windows command prompt, type:

And in Windows Powershell, type:

Environment variables are not required for using Antora. You can configure these variables using the corresponding command line options or in your playbook with the matching keys.

Environment variables take precedence over keys defined in the playbook file. However, the CLI option for a key takes precedence over the environment variable for that key.

If an environment variable (such as URL or https_proxy) is already set in your environment, and you wish to unset it temporarily when you run the antora command (i.e., a single invocation), you can do so using the env command:

Another option is to run the antora command in a subshell. Inside a subshell, you can unset an environment variable without it affecting the environment of your main shell or operating system.

Remember that environment variables take precedence over keys defined in your playbook file. So if you’re getting results you don’t expect, always check your environment variables to find out if they are the culprit.

The following table summarizes the environment variables you can use to control the operation of Antora.