How to Run Executable & Native Programs in an Ant Script

Apache Ant allows you to run executable files (.exe) and native programs using the <exec> task. This guide explains how to:
✅ Execute an external program or script
✅ Pass arguments to the program
✅ Handle output and errors
✅ Run Windows executables (.exe) and Unix shell scripts (.sh)

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1. Running an Executable (.exe) in Ant Script

If you have a Windows executable (e.g., myprogram.exe) and want to run it using Ant, use the <exec> task.

Example: Run an EXE File

<project name="RunExeExample" default="runExe" basedir=".">
    <target name="runExe">
        <exec executable="C:\path\to\myprogram.exe">
            <arg value="--option1"/>
            <arg value="value1"/>
        </exec>
    </target>
</project>

✅ This will run:

C:\path\to\myprogram.exe --option1 value1

Key Points:

• Replace C:\path\to\myprogram.exe with the actual path of your executable.
• Use <arg> to pass arguments to the executable.

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2. Running a Native Program (Any OS)

You can run system commands (e.g., cmd.exe for Windows or sh for Unix).

Example: Running a Shell Script (.sh)

<target name="runShell">
    <exec executable="sh">
        <arg value="-c"/>
        <arg value="ls -la"/>
    </exec>
</target>

✅ This runs the command:

sh -c "ls -la"

Example: Running a Windows Command (cmd.exe)

<target name="runCmd">
    <exec executable="cmd.exe">
        <arg value="/c"/>
        <arg value="dir"/>
    </exec>
</target>

✅ This runs:

cmd.exe /c "dir"

(Lists directory contents on Windows.)

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3. Capturing Output and Logging

You can capture output from the executable into a file or display it in the Ant log.

Example: Redirect Output to a Log File

<target name="runExeWithLog">
    <exec executable="C:\path\to\myprogram.exe" output="output.log" error="error.log"/>
</target>

✅ This saves standard output to output.log and errors to error.log.

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4. Setting Environment Variables

You may need to set environment variables before running an executable.

Example: Setting an Environment Variable

<target name="runWithEnv">
    <exec executable="myprogram.exe">
        <env key="MY_ENV_VAR" value="some_value"/>
    </exec>
</target>

✅ This sets MY_ENV_VAR=some_value before running myprogram.exe.

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5. Running Background Processes

To run a program without waiting for it to finish, set spawn="true".

<target name="runInBackground">
    <exec executable="C:\path\to\myprogram.exe" spawn="true"/>
</target>

✅ This starts myprogram.exe and allows Ant to continue execution.

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6. Full Example: Running an EXE, Capturing Output, and Setting Env Variables

<project name="FullExample" default="runExe" basedir=".">
    <target name="runExe">
        <exec executable="C:\path\to\myprogram.exe" output="program_output.log" error="program_error.log">
            <env key="CONFIG_PATH" value="C:\configs"/>
            <arg value="--config"/>
            <arg value="config.json"/>
        </exec>
    </target>
</project>

✅ This:

• Runs myprogram.exe --config config.json
• Captures output in program_output.log and errors in program_error.log
• Sets the environment variable CONFIG_PATH=C:\configs

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7. Conclusion

With Ant’s <exec> task, you can execute native programs, EXE files, and shell scripts, pass arguments, capture output, and set environment variables. 🚀

Would you like help automating builds, integrating with Java, or scheduling tasks in Ant? Let me know! 😊

Apache Ant <exec> Task Parameters Table

The <exec> task in Apache Ant is used to run external programs, executables, scripts, or system commands. The following table lists all the available parameters for the <exec> task along with their descriptions and example usage.

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📌 Table: <exec> Task Parameters

Parameter	Description	Required	Example Usage
executable	The program or command to execute (full path if necessary)	✅ Yes	<exec executable="cmd.exe"/>
dir	Specifies the working directory for the command execution	❌ No	<exec executable="myprogram.exe" dir="C:\mydir"/>
os	Restricts execution to specific OS (comma-separated)	❌ No	<exec executable="ls" os="Linux,MacOS"/>
failonerror	If true, the build fails on non-zero exit codes	❌ No (default: false)	<exec executable="myprogram.exe" failonerror="true"/>
spawn	If true, runs the process in the background	❌ No (default: false)	<exec executable="notepad.exe" spawn="true"/>
output	Captures the program’s standard output to a file	❌ No	<exec executable="myprogram.exe" output="output.log"/>
error	Captures the program’s error output to a file	❌ No	<exec executable="myprogram.exe" error="error.log"/>
input	Redirects a file as standard input for the process	❌ No	<exec executable="myprogram.exe" input="input.txt"/>
logerror	If true, logs error messages to the Ant console	❌ No (default: false)	<exec executable="myprogram.exe" logerror="true"/>
resultproperty	Stores the exit code of the command in a property	❌ No	<exec executable="myprogram.exe" resultproperty="exit.code"/>
timeout	Sets a timeout (in milliseconds) for execution	❌ No	<exec executable="myprogram.exe" timeout="5000"/>

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📌 Special Nested Elements in <exec>

Element	Description	Example Usage
<arg>	Passes command-line arguments	<arg value="--config config.json"/>
<env>	Sets environment variables for execution	<env key="JAVA_HOME" value="C:\Java"/>

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📌 Example: Full <exec> Task Usage

<project name="RunExecutable" default="execute" basedir=".">
    <target name="execute">
        <exec executable="C:\path\to\myprogram.exe" dir="C:\mydir" failonerror="true" timeout="10000" output="output.log" error="error.log">
            <arg value="--config"/>
            <arg value="config.json"/>
            <env key="CONFIG_PATH" value="C:\configs"/>
        </exec>
    </target>
</project>

✅ This script:

• Runs myprogram.exe --config config.json in C:\mydir
• Stops execution if an error occurs (failonerror="true")
• Captures standard output (output.log) and errors (error.log)
• Uses an environment variable CONFIG_PATH=C:\configs

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🎯 Conclusion

The <exec> task in Ant is highly flexible and allows running external programs with environment control, error handling, and logging. By using parameters and nested elements effectively, you can automate complex tasks seamlessly. 🚀

Would you like additional help with Ant automation, Java builds, or integrating with Jenkins? Let me know! 😊