Check that firefox is accessible

except.xml

 <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-enforcer-plugin</artifactId>
                <version>1.3.1</version>
                <executions>
                    <execution>
                        <id>enforce-beanshell</id>
                        <goals>
                            <goal>enforce</goal>
                        </goals>
                        <configuration>
                            <rules>
                                <evaluateBeanshell>
                                    <!-- Check whether firefox is accessible -->
                                    <message>Cannot find 'firefox' in your System PATH.</message>
                                    <condition>
                                        //MacOS X case
                                        mac = new File("/Applications/Firefox.app/Contents/MacOS/firefox");
                                        if (mac.isFile()) { return true;}

                                        // Linux and Windows
                                        candidates = new String[] { "firefox", "firefox.exe"};
                                        systemPath = System.getenv("PATH");
                                        if (systemPath == null) {
                                            return false;
                                        }
                                        pathDirs = systemPath.split(java.io.File.pathSeparator);

                                        for (pathDir : pathDirs) {
                                            for (candidate : candidates) {
                                                file = new java.io.File(pathDir, candidate);
                                                if (file.isFile()) {
                                                    return true;
                                                }
                                            }
                                        }
                                        System.out.println("Cannot find 'firefox' in your System Path");
                                        return false;
                                    </condition>
                                </evaluateBeanshell>
                            </rules>
                            <fail>true</fail>
                        </configuration>
                    </execution>
                </executions>
            </plugin>