RAT audits software distributions, with a special interest in headers. If this isn't quite what you're looking for then take a look at the other products developed by Apache Creadur™, including Apache Whisker™ which audits and generates legal (for example LICENSE) documents for complex software distributions.

There are several things to keep in mind when running RAT

RAT highlights possible issues.
RAT reports require interpretation.
RAT often requires some tuning before it runs well against a project.
RAT relies on heuristics: it may miss issues

Apache RAT Ant Task Library

The RAT Ant Task Library provides a single Ant task and supporting Ant types and properties to run RAT from inside Apache Ant.

Using Ant's resource abstraction the task can be used to check files on disk as well as tarballs or even URLs directly.

Requirements

The RAT Ant Task Library requires Apache Ant 1.7.1 or higher (it works well with 1.8.x), Apache RAT core and transitively all dependencies of Apache RAT core.

In order to use the tasks Java 5 is required as of RAT 0.9 - RAT 0.8 and earlier require Java 1.4.

Java 8 is required for RAT 0.14 and above.

Installation

There are several ways to use the Antlib:

The traditional way:
```
<taskdef
    resource="org/apache/rat/anttasks/antlib.xml">
    <classpath>
        <pathelement location="YOUR-PATH-TO/apache-rat-0.17.jar"/>
    </classpath>
</taskdef>
```
With this you can use the report task like plain Ant tasks, they'll live in the default namespace. For example if you can run exec without any namespace prefix, you can do so for report as well.

Similar, but assigning a namespace URI

<taskdef
    uri="antlib:org.apache.rat.anttasks"
    resource="org/apache/rat/anttasks/antlib.xml">
    <classpath>
        <pathelement location="YOUR-PATH-TO/apache-rat-0.17.jar"/>
    </classpath>
</taskdef>

This puts your task into a separate namespace than Ant's namespace. You would use the tasks like

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report>
        <fileset dir="src"/>
    </rat:report>
    ...
</project>

or a variation thereof.

Using Ant's autodiscovery. Place apache-rat-tasks.jar and all dependencies into a directory and use ant -lib DIR-CONTAINING-THE-JAR or copy it into ANT_HOME/lib - and then in your build file, simply declare the namespace on the project tag:
```
<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
```
and all tasks of this library will automatically be available in the rat namespace without any taskdef.

Adding license headers

RAT can be used to automatically add Apache-2.0 license headers to files that do not currently have them. Only files that are not excluded by the RAT configurations will be affected.

To add license headers use a command such as:

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report editLicense="y" editCopyright="Copyright 2008 Foo" editOverwrite="Y">
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>

This command will add the license header directly to the source files along with the copyright notice. If you prefer to see which files will be changed and how, then remove the "editOverwrite " attribute.

Excluding files from consideration

By default RAT Ant task includes all the files listed in an enclosed fileset. To exclude specific files within the set use one or more of the exclusion options. RAT uses a modified glob exclusion similar to Ant or Git.

RAT supports exclusion and inclusion. By default all files are processed. Using the exclude command files can be excluded from processing. In addition a file may be explicitly included. Files that are explicitly included can not be excluded.

Exclusion by glob pattern

The following command will exclude all files with a "foo" extension as well as all files in the junk folder at the root of the project.

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report>
        <inputExclude>
            <expr>**/*.foo</expr>
            <expr>junk/**</expr>
        </inputExclude>
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>

Exclusion by glob pattern file

It is often more efficient to place the exclusion patterns in a file and read that from disk. The following is an example of how to do that.

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report>
        <inputExcludeFile>
            <file file="/tmp/junit-5065932240072873529/excludeFile.xml" />
        </inputExclude>
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>

Using standard exclusions

RAT defines a number of standard collections that can be used to exclude files based on a standard pattern. For example to exclude all the files associated with the Git SCM

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report>
        <inputExcludeStd>
            <std>GIT</std>
        </inputExcludeStd>
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>

To exclude the files specified in the .gitignore files the inputExcludeParsedScm element is used.

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report>
        <inputExcludeStd>
            <std>GIT</std>
        </inputExcludeStd>
        <inputExcludeParsedScm>
            <std>GIT</std>
        </inputExcludeParsedScm>
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>

RAT will by default include all the files in hidden directories. To exclude the hidden files and directories and the git excluded resources the following command could be used:

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report>
        <inputExcludeStd>
            <std>GIT</std>
            <std>HIDDEN_FILE</std>
            <std>HIDDEN_DIR</std>
        </inputExcludeStd>
        <inputExcludeParsedScm>
            <std>GIT</std>
        </inputExcludeParsedScm>
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>

Excluding files by size

RAT will exclude files below a specified size if desired. This is done with the inputExcludeSize attribute. This attribute takes the the file size in bytes as an argument. The following will exclude files of 10 bytes or less.

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report inputExcludeSize="10">
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>

Including excluded files

The inputExclude, inputExcludeFile and inputExcludeStd> have include counterparts <<<inputInclude, inputIncludeFile>, inputIncludeStd. The include options will add files back to the processing list. For example, taking the earlier "inputExclude" example, if there was a file named "master/kung.foo" that should not be excluded the following command will ensure that it is processed.

<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report>
        <inputExclude>
            <expr>**/*.foo</expr>
            <expr>junk/**</expr>
        </inputExclude>
        <inputInclude>
            <expr>master/kung.foo</expr>
        </inputInclude>
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>

The order of the arguments is not important, the inputInclude> could have come before the inputExclude.

Styling output

RAT allows you to style the output as you see fit. Several stylesheets are included in the RAT package.

missing-headers - Produces a report of files that are missing headers.
plain-rat - The default style.
unapproved-licenses - Produces a report of the files with unapproved licenses.
xml - Produces output in pretty-printed XML.
These stylesheets can be specified using the outputStyle attribute. The following example creates a pretty printed xml report output.
```
<project
    xmlns:rat="antlib:org.apache.rat.anttasks"
    xmlns="antlib:org.apache.tools.ant">
    ...
    <rat:report outputStyle="xml">
        <fileset dir="path/to/source"/>
    </rat:report>
    ...
</project>
```
To develop your own stylesheets see the RAT Output section of the menu on the left.