CODEWITHSUNDEEP
javaant
digiarnie
digiarnie

Reputation: 23345

Check if environment variable has been set in Ant script

What is the most efficient way of checking if an environment variable has been set prior to executing the rest of an Ant script?

Let's say my Ant script requires the environment variable "FOO" to be set. I got the following to work, but I was wondering whether there was a less convulated way of achieving the same result:

<property environment="env"/>
<property name="env.FOO" value=""/>

<target name="my-target">
    <condition property="foo.found">
        <not>
            <equals arg1="${env.FOO}" arg2=""/>
        </not>
    </condition>
    <fail unless="foo.found" message="FOO not set."/>
    <!-- do stuff here that uses the FOO environment variable -->
</target>

Upvotes: 14

Views: 22235

Answers (6)

eric manley
eric manley

Reputation: 99

Here is what I came up with, using the isset property to check for a enviro variable that is only present on Unix. set.properties is the first target to kick this off.

<property environment="env" />        

<target name="init" depends="set.properties" />

    <!--  Do init stuff....  -->
    </target>

    <!-- Other target stuff.....  -->

<!--
        Target: set.properties
--> 
<target name="set.properties"       
 description="Initializes Build Script, checks displays properties"
     depends="cond.hostname.exist,cond.hostname.not.exist">
</target>

<!--
        Target: check.cond HostName is Present
-->     
<target name="cond.check">
    <condition property="cond-is-true">
            <isset property="env.HOSTNAME"/>
    </condition>
</target>   

<!--
        Target: cond.hostname.exist
-->         
<target name="cond.hostname.exist" depends="cond.check" if="cond-is-true">
    <property name="targetboxname"  value="${env.HOSTNAME}" />
</target>   

<!--
        Target: cond.hostname.not.exist
-->             
<target name="cond.hostname.not.exist" depends="cond.check" unless="cond-is-true">
    <property name="targetboxname"  value="${env.COMPUTERNAME}" />
</target>   

    <!-- Then later on....  -->
    <echo>ComputerName/HostName:  ${targetboxname}  </echo>

Upvotes: -1

David Harkness
David Harkness

Reputation: 36532

You can shorten it a bit by using an embedded <condition> inside <fail>.

<property environment="env"/>
<fail message="FOO not set.">
    <condition>
        <isset property="${env.FOO}"/>
    </condition>
</fail>

Upvotes: 0

David W.
David W.

Reputation: 107040

Close:

<fail message="FOO not set.">
    <condition>
        <isset property="env.FOO"/>
    </condition>
</fail>

This won't fail if $FOO was set, but is null.

Upvotes: 1

matt
matt

Reputation: 79723

Isn't this as simple as:

<property environment="env"/>
<fail unless="env.FOO" message="FOO not set."/>

Upvotes: 26

Op De Cirkel
Op De Cirkel

Reputation: 29473

and the other thing you can do (additional to David's) is use 

<isset property="env.Foo"/> instead of <equals />

Upvotes: 9

Saurabh Gokhale
Saurabh Gokhale

Reputation: 46395

<property name="test.home.0" value="${env.TEST_HOME}"/>
<condition property="test.home" value="TO_BE_REPLACED">
  <equals arg1="${test.home.0}" arg2="\${env.TEST_HOME}"/>
</condition>
<property name="test.home" value="${env.TEST_HOME}"/>

<target name="test">
  <echo>TEST_HOME: ${test.home}</echo>
</target>

Upvotes: 0

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