Ant script -- split string and access via indexing - arrays

Question

I need to write an Ant script which would load a properties file, read a single property out of it. The value (multiline) is something like:
path/to/file1a;path/to/file1b,
path/to/file2a;path/to/file2b,
..
..
I need to iterate over every line, and execute a shell command which looks like:
myCommand -param1 path/to/file1a -param2 path/to/file1b #Command inside a single iteration
I have able to figure out how to loop:
<for list="${ValueFromPropertyFile}" param="a">
<sequential>
<exec executable="myCommand">
<arg value="-param1" />
<arg value="---- split(#{a}, ";")[0] ----" />
<arg value="-param2" />
<arg value="---- split(#{a}, ";")[1] ----" />
</exec>
</sequential>
</for>
This is quite a simple task in my opinion. I tried searching, but without any success.
I would appreciate if someone could help me out with this, or point me to a relevant document.
Many thanks,
Pratik

Answer 1

Couple of problems with your assumptions:
The format of your input file is not a standard Java properties file, so it can't be loaded using the standard loadproperties task in ANT.
ANT is not a programming language. The "for" task you've quoted is not part of core ANT (Requires the 3rd party ant-contrib.jar)
So I'd suggest using an embedded script to solve your problem.
Example
The project is self documenting:
$ ant -p
Buildfile: /home/mark/tmp/build.xml
This is a demo project answering the following stackoverflow question:
http://stackoverflow.com/questions/14625896
First install 3rd party dependencies and generate the test files
ant bootstrap generate-test-files
Then run the build
ant
Expect the following output
parse-data-file:
[exec] build/myCommand -param1 path/to/file1a -param2 path/to/file1b
[exec] build/myCommand -param1 path/to/file2a -param2 path/to/file2b
build.xml
<project name="demo" default="parse-data-file">
<description>
This is a demo project answering the following stackoverflow question:
http://stackoverflow.com/questions/14625896
First install 3rd party dependencies and generate the test files
ant bootstrap generate-test-files
Then run the build
ant
Expect the following output
parse-data-file:
[exec] build/myCommand -param1 path/to/file1a -param2 path/to/file1b
[exec] build/myCommand -param1 path/to/file2a -param2 path/to/file2b
</description>
<target name="bootstrap" description="Install 3rd party dependencies">
<mkdir dir="${user.home}/.ant/lib"/>
<get dest="${user.home}/.ant/lib/groovy-all.jar" src="http://search.maven.org/remotecontent?filepath=org/codehaus/groovy/groovy-all/2.1.0/groovy-all-2.1.0.jar"/>
</target>
<target name="generate-test-files" description="Generate the input data and sample script">
<echo file="build/input.txt">path/to/file1a;path/to/file1b,
path/to/file2a;path/to/file2b,</echo>
<echo file="build/myCommand"> #!/bin/bash
echo $0 $*</echo>
<chmod file="build/myCommand" perm="755"/>
</target>
<target name="parse-data-file" description="Parse data file">
<taskdef name="groovy" classname="org.codehaus.groovy.ant.Groovy"/>
<groovy>
new File("build/input.txt").eachLine { line ->
def fields = line.split(/[;,]/)
ant.exec(executable:"build/myCommand") {
arg(value:"-param1")
arg(value:fields[0])
arg(value:"-param2")
arg(value:fields[1])
}
}
</groovy>
</target>
<target name="clean" description="Cleanup build files">
<delete dir="build"/>
</target>
</project>