Ant: How to strip the basedir from an absolute path to get a relative path?

Question

In the build.xml of my project I have a property defined:

<property name="somedir.dir" location="my_project/some_dir"/>

The value of "${somedir.dir}" will be an absolute path: "/home/myuser/my_project/some_dir". But what I need is just the relative path "./my_project/some_dir" without the ${basedir} value "/home/myuser". How can I achieve this in Ant?

So far I found a solution by converting the property to a path and then use "pathconvert", but I don't think this is a nice solution:

<path id="temp.path">
    <pathelement location="${somedir.dir}" />
</path>
<pathconvert property="relative.dir" refid="temp.path">
    <globmapper from="${basedir}/*" to="./*" />
</pathconvert>

Any other (more elegant) suggestions? Thanks!

Answer 1

location expands automatically the path using the project's basedir. So I think value option gives you a better control:

<property name="base.dir" value="/home/myuser"/>

and

<property name="somedir.dir" value="${base.dir}/some_dir"/>

Answer 2

You might be able to use the http://ant.apache.org/manual/CoreTasks/basename.html Basename task. If you have:

    <property name="somedir" value="/path/to/file/here" />
    <basename file="${somedir}" property="somebasedir" />
    <echo>${somebasedir}</echo>

The value that gets echoed is "here". It only seems to give you the final directory, which might not get enough of what you want.