CODEWITHSUNDEEP
ant
Magnus
Magnus

Reputation: 1271

Conditionally redirecting output in ant exec task

Is there a way of conditionally redirecting the output to property or the stdout stream as the non-working example below?

<macrodef name="mytask">
  <attribute name="output" default="STDOUT"/>
  <sequential>
      <exec executable="my.exe" outputproperty="@{output}"/>
  </sequential>
</macrodef>

The above example redirects the output by default to a property STDOUT. Instead I would like it to be directed to the stdout stream.

I could create mytask_with_stdout as a copy of the above macro and remove the exec outputproperty, but that would violate the DRY principle.

Is there some nice way of doing this?

Upvotes: 2

Views: 2688

Answers (1)

Chad Nouis
Chad Nouis

Reputation: 7051

There are two Ant features you can combine to get what you want.

First, a <macrodef> can be passed whatever <element> you want.

Second, a <redirector> can be used to capture the output of an <exec> command in a property.

I ran the following Ant script on a Windows machine so I could use cmd.exe's echo command. Replace the cmd.exe with your my.exe:

<project name="exec-redirector-example" default="run">
    <macrodef name="mytask">
        <attribute name="message"/>
        <element name="myredirector" optional="true"/>
        <sequential>
            <exec executable="cmd.exe">
                <arg value="/c"/>
                <arg value="echo"/>
                <arg value="@{message}"/>
                <myredirector/>
            </exec>
        </sequential>
    </macrodef>

    <target name="run">
        <!-- exec outputs to STDOUT by default -->
        <mytask message="To STDOUT">
        </mytask>

        <!-- exec outputs to a property in this example -->
        <mytask message="To property">
            <myredirector>
                <redirector outputproperty="my.property"/>
            </myredirector>
        </mytask>

        <echo>${my.property}</echo>
    </target>
</project>

Upvotes: 2

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