function::target — Return the process ID of the target process
target:long()
This function returns the process ID of the target process. This is useful in conjunction with the -x PID or -c CMD command-line options to stap. An example of its use is to create scripts that filter on a specific process.
 -x <pid> target returns the pid specified by -x 
 -c <command> target returns the pid for the executed command specified by -c