Running JAuto

JAuto is a JVMTI (Java Virtual Machine Tool Interface) agent. It runs in the JVM with a target Java program. To run JAuto, first figure out the command line to run the target Java program, which is:

$ java -jar TargetProgram.jar

Then add an argument to specific loading of JAuto, like the following:

$ java -jar TargetProgram.jar -agentpath:/path/to/jauto.so

Some programs may come with a launch script. You will need to inspect the launch script source to understand whether it provided a mechanism to add JVM arguments, or you have to modify the script directly to make it work. A common mechanism is a .vmoptions file, which is a text file where you can add JVM arguments one per line.

For more information regarding the agentpath argument, please refer to JVMTI documentation.

A successful start of the target Java program typically means a successful start of JAuto. To verify it, enter the following command in a shell:

$ echo "/tmp/test.txt|ping" > /tmp/jauto.in

If JAuto is working, it will write pong into file /tmp/test.txt. Inspect its content by:

$ cat /tmp/test.txt

Due to the threaded and asynchronous processing of commands in JAuto, there might be a small delay in file generation. It is normal if the file did not immediately appear after entering the command.