I need to determine whether the user is on linux OS or windows OS. For this I use the condition statement. I gave it a value and an else value. My only question now is: How can I obtain the condition value regardless and use it? I need the obtained value to concatenate it to a part of my string so I can retrieve the correct JAR files.

My code looks like this:

<project name="myproj" default="dist">
    <property file="build.properties"/>
    <property file="${user.home}/build.properties"/>

    <path id="run.classpath">
        <fileset dir="${dist.dir}">
            <include name="${project.name}.jar"/>
        </fileset>
    </path>

    <condition property="platformDetected" value="win" else="linux">
        <os family="windows" />
    </condition>

    <target name="compile">
        <mkdir dir="${bin.dir}"/>
        <javac srcdir="${src.dir}"
               destdir="${bin.dir}"
               debug="${compile.debug}"
               deprecation="${compile.deprecation}"
               optimize="${compile.optimize}"
               includeantruntime="false">
                <classpath>
                    <fileset dir="${lib.dir}/javafx-sdk-18-${platformDetected}/lib">
                        <include name="**/*.jar" />
                    </fileset>
                </classpath>
                <classpath>
                    <fileset dir="${lib.dir}/postgresql">
                        <include name="**/*.jar" />
                    </fileset>
                </classpath>
                <classpath>
                    <fileset dir="${lib.dir}/csvreader">
                        <include name="**/*.jar" />
                    </fileset>
                </classpath>
                <compilerarg line="--module-path ${lib.dir}/javafx-sdk-18-${platformDetected}/lib/"/>
                <compilerarg line="--add-modules javafx.controls"/>
        </javac>
    </target>

    <target name="dist" depends="compile">
        <mkdir dir="${dist.dir}"/>
        <jar jarfile="${dist.dir}/${project.name}.jar"
             basedir="${bin.dir}"
             manifest="${src.dir}/Manifest.mf">
             <zipgroupfileset dir="${lib.dir}/javafx-sdk-18-${platformDetected}/lib" includes="**/*.jar"/>
             <zipgroupfileset dir="${lib.dir}/postgresql" includes="**/*.jar"/>
             <zipgroupfileset dir="${lib.dir}/csvreader" includes="**/*.jar"/>
        </jar>
    </target>

    <target name="build" depends="dist">
        <java jar="${dist.dir}/${project.name}.jar" fork="true">
            <jvmarg line="--module-path ${lib.dir}/javafx-sdk-18-${platformDetected}/lib/"/>
            <jvmarg line="--add-modules javafx.controls"/>
        </java>
    </target>

    <target name="clean">
        <delete dir="${bin.dir}"/>
        <delete dir="${dist.dir}"/>
    </target>
</project>

How can I call this:

    <condition property="platformDetected" value="win" else="linux">
        <os family="windows" />
    </condition>

and pass it to this line (for example):

<jvmarg line="--module-path ${lib.dir}/javafx-sdk-18-${platformDetected}/lib/"/>

Edit: Aparently I am already doing it right(?), but I end up having an error.

The error which is produced when I run ant build is:

     [java] Graphics Device initialization failed for :  d3d, sw
 [java] Error initializing QuantumRenderer: no suitable pipeline found
 [java] java.lang.RuntimeException: java.lang.RuntimeException: Error initializing QuantumRenderer: no suitable pipeline found
 [java]     at javafx.graphics@18/com.sun.javafx.tk.quantum.QuantumRenderer.getInstance(QuantumRenderer.java:283)
 [java]     at javafx.graphics@18/com.sun.javafx.tk.quantum.QuantumToolkit.init(QuantumToolkit.java:253)
 [java]     at javafx.graphics@18/com.sun.javafx.tk.Toolkit.getToolkit(Toolkit.java:266)
 [java]     at javafx.graphics@18/com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:291)
 [java]     at javafx.graphics@18/com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:163)
 [java]     at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.startToolkit(LauncherImpl.java:659)
 [java]     at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:410)
 [java]     at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:364)
 [java]     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 [java]     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
 [java]     at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 [java]     at java.base/java.lang.reflect.Method.invoke(Method.java:567)
 [java]     at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1071)
 [java] Caused by: java.lang.RuntimeException: Error initializing QuantumRenderer: no suitable pipeline found
 [java]     at javafx.graphics@18/com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.init(QuantumRenderer.java:95)
 [java]     at javafx.graphics@18/com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:125)
 [java]     at java.base/java.lang.Thread.run(Thread.java:831)
 [java] Exception in thread "main" java.lang.reflect.InvocationTargetException
 [java]     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 [java]     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
 [java]     at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 [java]     at java.base/java.lang.reflect.Method.invoke(Method.java:567)
 [java]     at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1071)
 [java] Caused by: java.lang.RuntimeException: No toolkit found
 [java]     at javafx.graphics@18/com.sun.javafx.tk.Toolkit.getToolkit(Toolkit.java:278)
 [java]     at javafx.graphics@18/com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:291)
 [java]     at javafx.graphics@18/com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:163)
 [java]     at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.startToolkit(LauncherImpl.java:659)
 [java]     at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:410)
 [java]     at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:364)
 [java]     ... 5 more
 [java] Java Result: 1