windows-ansi

windows-ansi is a small Java library to setup / interact with a Windows terminal. It allows to

• query the terminal size, and
• change the console mode so that it accepts ANSI escape codes.

It relies on internals of the jansi library to do so, and also works from GraalVM native images.

Compared to using jline, windows-ansi only and solely calls the right kernel32.dll system calls (like SetConsoleMode or GetConsoleScreenBufferInfo), lowering the odds of something going wrong when generating or using a GraalVM native image for example.

Usage

Add to your build.sbt

libraryDependencies += "io.github.alexarchambault.windows-ansi" % "windows-ansi" % "0.0.1"

The latest version is .

The WindowsAnsi methods should only be called from Windows. You can check that the current application is running on Windows with:

boolean isWindows = System.getProperty("os.name")
        .toLowerCase(java.util.Locale.ROOT)
        .contains("windows");

Alternatively, when using Graal native image, the following should work too, and has the benefit of simply discarding one of the if branches at image generation time:

// requires the org.graalvm.nativeimage:svm dependency,
// which can usually be marked as "provided"
if (com.oracle.svm.core.os.IsDefined.WIN32()) {
    // call io.github.alexarchambault.windowsansi.WindowsAnsi methods
} else {
    // not on Windows, handle things like you would on Unixes
}

Change terminal mode

Change the terminal mode so that it accepts ANSI escape codes with

import io.github.alexarchambault.windowsansi.WindowsAnsi;

boolean success = WindowsAnsi.setup();

A returned value of false means ANSI escape codes aren't supported by the Windows version you're running on. These are supposed to be supported by Windows 10 build 10586 (Nov. 2015) onwards.

Get terminal size

import io.github.alexarchambault.windowsansi.WindowsAnsi;

WindowsAnsi.Size size = WindowsAnsi.terminalSize();
int width = size.getWidth();
int height = size.getHeight();

License

All files in this repository, except NativeImageFeature.java, can be used either under the Apache 2.0 license, or the GNU GPL version 2 license, at your convenience.

The NativeImageFeature.java file, originally based on a GNU GPL version 2 only file, is licensed only under the GNU GPL version 2 license.