Question

I’d like to update my ANT's build.xml file to:

1. Read a value from the file and
2. Change link on the system to reflect what it read in file

Assume the file to have content in the following format:

Environment = dev

Further assume directory to have the following files/link:

current_env_image -> qa_image.jpg
prod_image.jpg
qa_image.jpg
dev_image.jpg

.. where current_env_image is a link to whatever the current image should be presented at.

I’d like for an ANT script to:

1. Read the value assigned to Environment (from the file) and
2. Execute a command creating a link to point to the right image:

unlink current_env_image

ln -s ${environment}_image.jpg current_env_image

Answer 1

Reading the file can be easily done with the Property task:

  <property file="foo.properties"/>

reads a set of properties from a file called "foo.properties".

Afterwards your variable Environment will be set to that value.

The second question could be achieved by the exec task

  <exec executable="ln">
    <arg value="-s ${environment}_image.jpg image"/>
  </exec>