How to check if directory exists before deleting it, using ANT?

Question

Using ANT, how can i make sure that directory exists before attempting to remove it?

As part of my current clean task, i

<target name="clean" description="clean">
    <delete dir="${build}" />
    <delete dir="${bin}" />
    <delete dir="${dist}/myrunner.${version}.jar" />
    <delete dir="${doc}" />
    <delete dir="${report}" />
</target>

This works well, however (obviously) remove happens when there is something to remove.

Using ANT, how can i check if directory exist?

Is there a reason you need to check if the directory exists before deleting it? — Richard Steele, Sep 08 '11 at 23:06

ekangas · Answer 1 · 2012-10-22T17:04:12.010

43

For this specific case, I'm not going to answer the question "how to find if a directory exists", because that's already been answered, but I'm just going to point out that in your clean task you can use failonerror="false" to keep the ant task from exiting. This should be suitable in a clean task because if there's nothing to clean, it should not be a problem.

    <target name="clean" description="clean">
        <delete dir="${build}" failonerror="false"/>
        ....
        <delete dir="${report}" failonerror="false"/>
    </target>

This is useful if you don't want to install ant-contrib or can't for some reason.

edited Oct 22 '12 at 17:04

answered Oct 22 '12 at 16:56

ekangas

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What if there's something to clean but it fails on some other error, for example someone has locked a file in the directory for editing? You'd want those errors to be reported. – Carlos Aug 27 '14 at 07:39
Simple. Clean. Nice answer. – james.garriss Feb 10 '15 at 19:17
5

I agree with Carlos. You will miss real errors with failonerror="false". To ignore all kinds of error just to avoid failing, if everything is already clean seams to be a bad idea. – niks Mar 02 '16 at 10:54
Certainly, this is the right way to do it. In the "clean" goal, and adding the "failonerror" flag. – marcello Mar 12 '20 at 19:30
I also agree with @Carlos. In the case of a missing directory, I set quiet="true" in the delete task to emulate the Unix 'rm -f' command, which accepts a missing directory as a non-fatal event. This still allows other IO errors to be enforced. – Steven Darnell Feb 16 '22 at 19:37

score 18 · Answer 2 · edited May 23 '17 at 12:17

18

with vanilla ant you would use something like =

 <target name="check">
  <condition property="deldir">
    <available file="${somedir}" type="dir"/>
  </condition>
 </target>

 <target name="deldir" depends="check" if="deldir">
 <delete dir="${somedir}"/>
    <!-- .. -->
 </target>

else see = Ant check existence for a set of files
for a similar question

edited May 23 '17 at 12:17

Community

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answered Jun 13 '11 at 19:39

Rebse

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James Raitsev · Accepted Answer · 2011-09-03T23:55:45.797

Nice and clean solution below: Using ant-contribs.jar

When using this solution, be sure to put the following line on top

<!-- For <if> statements -->
<taskdef resource="net/sf/antcontrib/antlib.xml" />


<!-- Remove distribution directories and their content for a clean build -->
    <target name="clean" description="clean">

        <if>
            <available file="${build}" type="dir" />
            <then>
                <delete dir="${build}" />
            </then>
        </if>
    </target>

score 3 · Answer 4 · edited May 23 '17 at 11:54

3

Check out the available task.

Here's a similar question.

Do I have a way to check the existence of a directory in Ant (not a file)?

edited May 23 '17 at 11:54

Community

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answered Jun 13 '11 at 19:06

pjeong

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score 1 · Answer 5 · edited Oct 21 '14 at 10:53

1

Here is the answer :

    <target name="delete.target.directory">  
        <delete includeemptydirs="true" verbose="false" if="${(directory::exists(directory))}">
            <fileset basedir="${directory}">  
                <include name="**/*.*" />  
            </fileset> 
        </delete>
    </target>

edited Oct 21 '14 at 10:53

Soner Gönül

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answered Oct 21 '14 at 10:37

TuciBeyin

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What version of ANT is this? Version 1.9.6 fails with 'delete doesn't support the "if" attribute'. – Flávio Etrusco Apr 11 '18 at 14:27

score 0 · Answer 6 · answered May 16 '14 at 14:41

You can do it by ordering to delete a list of files with names equal to the name you need. It is much easier and direct than to create a special target. And you needn't any additional tools, just pure Ant.

    <delete>
        <fileset includes="name or names of file or files you need to delete"/>
    </delete>

http://ant.apache.org/manual/Types/fileset.html

score 0 · Answer 7 · answered Nov 25 '20 at 13:18

You can use this brute force technique as pure ant, which is specially useful in maven where the additional conditionals aren't available.
The mkdir will do nothing if the directory already exists, and the delete will fail if the folder cannot be deleted for some reason. The condition of the file not being there is common in a build script where one of the build steps fail but the initial clean was performed.

<target name="clean">
    <mkdir dir="${project.basedir}/dist" />
    <delete dir="${project.basedir}/dist" />
</target>

How to check if directory exists before deleting it, using ANT?

7 Answers7

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