Call shell script from Apache Ant build on Mac OS X

Guys, you might come across some situations where you need to invoke shell and execute a bash script while building a project using Apache Ant. In today's example let's see how to run a shell script from within an Ant build.

For illustration, lets create a simple bash script to list the disk usage of our system. Let's name this file as "DiskUsage.sh"

#!/bin/bash

# Sample shell script to be invoked from an Ant build

echo "Disk usage is as follows : \n"

echo "=========================== \n"

df -h

Now let's create a simple build-test.xml using the exec command to invoke the shell as follows :

<?xml version="1.0" encoding="UTF-8"?>

<project name="AntBuildTest" default="call-shell" basedir=".">

<target name="call-shell">

<exec executable="/bin/bash">

<arg value="DiskUsage.sh"/>

</exec>

</target>

</project>

Run the ant build from command line as ant -f build-test.xml. Note that the shell script and build.xml happen to be at the same location/hierarchy within the project. If your shell script lies elsewhere, you may perhaps want to refer to its path in the build.properties instead.

You could also invoke the "expect" scripting prompt in a similar fashion to execute an expect script that we discussed in our earlier post.

More information on the exec can be read at the official Ant manual.

Ant - Build.xml Updates - 28 Feb

Guys, in my earlier posts we learnt how to write a simple basic build.xml and also learnt about the build.properties. Today we'll modify, update our build.xml to include some more functionality.

Let's add the following 2 features :

• add a MANIFEST.MF file to the jar package which will contain the packaging information
• create documentation using javadoc.

Check out the updated build.xml with the tasks for the same below :

<?xml version="1.0" encoding="UTF-8"?>

<project name="AntBuildTest" default="generate-docs" basedir=".">

<property name="build.home" value="${basedir}" />

<property file="build.properties"/>

<tstamp>

<format property="timestamp" pattern="dd-MM-yyyy"/>

</tstamp>

<target name="clean">

<delete dir="${build.home}/src" />

<delete dir="${build.home}/bin" />

<delete dir="${build.home}/lib" />

<delete dir="${build.home}/test" />

<delete dir="${build.home}/dist" />

<delete dir="${build.home}/docs" />

<delete dir="${build.home}/logs" />

</target>

<target name="createdir" depends="clean">

<mkdir dir="${build.home}/src" />

<mkdir dir="${build.home}/bin" />

<mkdir dir="${build.home}/lib" />

<mkdir dir="${build.home}/test" />

<mkdir dir="${build.home}/dist" />

<mkdir dir="${build.home}/docs" />

<mkdir dir="${build.home}/logs" />

</target>

<path id="classpath">

<pathelement location="${build.home}/bin"></pathelement>

<fileset dir="${lib.dir}" includes="**/*.jar"/>

</path>

<target name="copydir" depends="createdir">

<copydir src="${workspace.src}"

dest="${build.home}/src"></copydir>

</target>

<target name="compile" depends="copydir, clean">

<javac classpathref="classpath" includeantruntime="false"

srcdir="${build.home}/src"

destdir="${build.home}/bin"

includes="**/*.java"></javac>

</target>

<target name="create-jar" depends="compile">

<jar basedir="${build.home}/bin" destfile="${build.home}/dist/${timestamp}-TestJar-${versionnum}.jar"

includes="**/*.class">

<manifest>

<attribute name="Main-class" value="com.ironcladzone.FileSize"/>

</manifest>

</jar>

</target>

<target name="generate-docs" depends="create-jar">

<javadoc sourcepath="${build.home}/${src.dir}" destdir="docs"/>

</target>

</project>

Notice the "create-jar" target where we have added the <manifest></manifest> tags in which we have mentioned the main class for instance. This will create a MANIFEST.MF file within the jar. I'll write a new post on the Manifest file soon.

Also for the javadoc, we have a new target named "create-documentation". If you check the folder structure, you'll find the index.html within the docs folder. Try looking into the index.html, you'll see the class and package details in a sample webpage decorated with the default javadoc css stylesheet.

Recover and restore deleted files from Eclipse Navigator

Have you come across a situation where you accidentally deleted source code from the Eclipse Navigator. Just don't panic in such a case. There's a way to recover and restore these deleted files.

Simply right click the project from the Navigator pane and choose the following option :

In the next screen, you'll see the list of all files that you deleted and wish to restore back. Just choose the necessary files, click Restore and relax!

View Jar contents without opening on Mac OS X

Hello readers, today's topic is a fairly basic interview question wherein you are asked to view the jar package contents without exploding/opening it.

In order to do so, type the following in terminal for example :

unzip -l 28-02-2016-TestJar-1.8.jar 

Output : 

Archive:  28-02-2016-TestJar-1.8.jar

  Length     Date   Time    Name

 --------    ----   ----    ----

        0  02-28-16 13:34   META-INF/

      142  02-28-16 13:33   META-INF/MANIFEST.MF

        0  02-28-16 13:33   com/

        0  02-28-16 13:33   com/ironcladzone/

      571  02-28-16 13:33   com/ironcladzone/Create_Directory.class

      755  02-28-16 13:33   com/ironcladzone/FileSize.class

      367  02-28-16 13:33   com/ironcladzone/HelloICZ.class

      463  02-28-16 13:33   com/ironcladzone/String_mani1.class

      534  02-28-16 13:33   com/ironcladzone/String_manip2.class

      601  02-28-16 13:33   com/ironcladzone/String_manip3.class

      407  02-28-16 13:33   com/ironcladzone/String_manip4.class

      474  02-28-16 13:33   com/ironcladzone/String_manip5.class

      935  02-28-16 13:33   com/ironcladzone/User_Input.class

      201  02-28-16 13:33   com/ironcladzone/callMacApp.class

      909  02-28-16 13:33   com/ironcladzone/operator1.class

 --------                   -------

     6359                   15 files

Note the -l switch is for listing the jar contents. You can use the same technique for any kind of package - jar / war / tar / ear etc.

Automate tasks using Expect scripts on Mac OS X

Expect is one of the hidden gems and quite esoteric scripting language for automating tasks on Mac OS X and on most unix flavors.

The idea behind expect is you can program the response to a programmed request string. It's much like a pre-programmed auto-complete feature, in which you have already told the system what the response should be, if it comes across a specific expected request.

Let's try out a basic simple script. In terminal create a new script file : vi expect_test.exp
Note the .exp extension, similar to .sh of bash scripts.

#!/usr/bin/expect

expect "hello"

send "Welcome to IroncladZone \n"

Now if you execute the script ./expect_test.exp and type the string "hello", it will automatically send the response "Welcome to IroncladZone".

Ant - Delete only files from directories

For an Ant build, if you just want to delete files without deleting the directory, consider the following. For illustration, we'll take the folder structure as mentioned in our earlier post.

Let's say I want to only clear the class files generated in the bin/com/ironcladzone directory.

<?xml version="1.0" encoding="UTF-8"?>

<project name="AntBuildTest" default="clean-class-files" basedir=".">

<property name="build.home" value="${basedir}" />

<property file="build.properties"/>

<target name="clean-class-files">

<delete>

<fileset dir="${bin.dir}">

<include name="**/*"/>

</fileset>

</delete>

</target>

</project>

Note : by using **/*, it will recursively delete all the files from the bin/ subdirectories. Using the <fileset> tag, we mention the directory tree, on which the delete operation needs to be performed.

List only target names from build.xml in Apache Ant

In Apache Ant, for listing only the target names defined in the build.xml, all we have to do is type the following from command line :

Eg :

ant -p build.xml

Output :

Buildfile: /Users/ironcladzone/Documents/workspace/AntBuildTest/build/build.xml

Main targets:

Other targets:

 clean

 compile

 copydir

 create-jar

 createdir

Default target: create-jar