Ant: How to use apply task with identical source and target file

Question

I am trying to run an apply task with the following command:

  jpegtran.exe -copy none -optimize -perfect ./images/file.jpg ./images/file.jpg

I would like to apply it recursively for all images. I have tried the following ant code but jpegtran says invalid arguments.

<target name="optimize.images.jpg">
    <apply executable="jpegtran.exe" dir="${SRC_DIR}/public/assets/" parallel="false" verbose="true" resolveexecutable="true" force="true" vmlauncher="true">
        <arg value="-copy none"/>
        <arg value="-optimize"/>
        <arg value="-perfect"/>
        <srcfile/>
        <targetfile/>
        <fileset dir="${SRC_DIR}/public/assets/images" casesensitive="yes">
            <include name="**/*.jpg"/>
        </fileset>
        <mapper type="identity"/>
    </apply>
</target>

What could be wrong with my ant code?

Answer 1

One item that needs to be changed is the nested <arg> element for -copy none. Since there is a space in the argument, use the line attribute instead of value. See Apache Ant command line arguments.

<target name="optimize.images.jpg">
  <apply executable="jpegtran.exe" dir="${SRC_DIR}/public/assets/" 
    parallel="false" verbose="true" resolveexecutable="true" force="true" 
    vmlauncher="true">

    <arg line="-copy none"/>
    <arg value="-optimize"/>
    <arg value="-perfect"/>
    <srcfile/>
    <targetfile/>
    <fileset dir="${SRC_DIR}/public/assets/images" casesensitive="yes">
      <include name="**/*.jpg"/>
    </fileset>
    <mapper type="identity"/>
  </apply>
</target>