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.

What I need is just the relative path ./my_project/some_dir without the ${basedir} value /home/myuser. How can I achieve this using 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?

Answer 1

Since Ant 1.8.0 you can use the relative attribute of the Ant property task for this.

For example:

<property name="somedir.dir" location="my_project/some_dir"/>
<echo message="${somedir.dir}" />

<property name="somedir.rel" value="${somedir.dir}" relative="yes" />
<echo message="${somedir.rel}" />

Leads to:

 [echo] /home/.../stack_overflow/ant/my_project/some_dir
 [echo] my_project/some_dir

Answer 2

A slightly less verbose solution would be specifying somepath inside <pathconvert>:

<pathconvert property="relative.dir">
  <path location="${somepath}"/>
  <globmapper from="${basedir}/*" to="./*" />
</pathconvert>

Answer 3

You might be able to use the Ant 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.

Answer 4

This was the approach that worked well for me in Windows, adapted from @Garns answer:

<path id="uploadFilePath">
    <fileset dir="${wcm.folderName}">
        <include name="*" />
        <exclude name="*.attr" />
    </fileset>
</path>

<pathconvert property="relFilelist">
    <path refid="uploadFilePath" />
    <mapper>
        <globmapper from="${wcm.folderName}/*" to="*" handledirsep="true" />
    </mapper>
</pathconvert>

I think that handledirsep="true" is pretty important in globmapper, it didn't work for me otherwise no matter how much I fiddled with forward/backslashes. (I do all my slashes as forward in my ant scripts just so I can run them on unixy systems.) My version of Ant is 1.8.1.

Answer 5

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"/>