You can set use the input task to make Ant ask for parameters on the command line at runtime.

<target
    name    = "test1"
    description    = "testing the input task"
    >
    <input
        message    = "Press [Enter] to continue"
        />
</target>
This will display a message and wait.

<target
    name    = "test1"
    description    = "testing the input task"
    >
    <input
        message    = "Type a number"
        addproperty    = "myNumber"
        defaultvalue    = "-1"
        />
    <echo
        message    = "You have typed: ${myNumber}" />
</target>

This will
• display a message
• wait for the user to type in something and / or press return;
• either assign what the user to typed in to the property myNumber, or the default value of “-1″
• display the property in a message.


<target
    name    = "test3"
    description    = "testing the input task"
    >
    <input
        message    = "Type in a number between 0 and 9999"
        addproperty    = "myNumber"
        defaultvalue    = "0"
        />
    <condition property="is_number">
        <matches pattern="^[1-9]{1,4}$" string="${myNumber}"/>
    </condition>
    <fail message="Incorrect input (${myNumber}) "
        unless="is_number"/>
    <echo
        message    = "You have typed: ${myNumber}" />
</target>


This will
• display a message
• wait for the user to type in something and / or press return;
• either assign what the user to typed in to the property myNumber, or the default value of “-1″
• run the condition task with the matches regular expression to validate the property myNumber, and put the result of the validation into the is_number property (there is also a regular expression element for more complex validation).
• look at the is_number property and abort the task if it set to false, displaying an error message
• If validation had passed, it displays a message containing the myNumber property