Replace characters Using ANT

There is an inbuilt task given in ant library called 'replaceregexp'. This task is used to check about a specific pattern i.e. a regular expression and replace them with a different pattern in a single file or set of files.

Replace in a set of files

<replaceregexp match="test" replace="replacedTest" flags="gm" byline="false">
            <fileset dir="${sf.srcdir}" includes="*.txt" />
</replaceregexp>

The above task will look at all the files ending with extension 'txt' in the source directory given as 'sf.srcdir' in the properties file. In all those files, it tries to find the pattern 'test' and replaces with pattern 'replacedTest'

Fail an ANT build if a property is not set

Any number of properties can be used in ANT build.xml. They can be environment variables or variables set in a properties file.

There is an ability to check if required properties are set or not i.e. included or not in the properties file. Also we can match them to a regular expression to see of they are empty or matching as per the requirement. If they do not match the requirement, the build can be made to fail. There is a fail task provided by the ant library to fail the build. Add this as first task before adding any cutom tasks.

Including Properties File

You can include a properties file or environmental variables in build.xml in the below way
    <property file="build.properties"/>
    <property environment="env"/>