How to Finding All Runnable Processes

How to kill all processes with a given partial name?

Use pkill -f, which matches the pattern for any part of the command line

pkill -f my_pattern

Just in case it doesn't work, try to use this one as well:

pkill -9 -f my_pattern

Find and kill a process in one line using bash and regex

In bash, you should be able to do:

kill $(ps aux | grep '[p]ython csp_build.py' | awk '{print $2}')

Details on its workings are as follows:

• The ps gives you the list of all the processes.
• The grep filters that based on your search string, [p] is a trick to stop you picking up the actual grep process itself.
• The awk just gives you the second field of each line, which is the PID.
• The $(x) construct means to execute x then take its output and put it on the command line. The output of that ps pipeline inside that construct above is the list of process IDs so you end up with a command like kill 1234 1122 7654.

Here's a transcript showing it in action:

pax> sleep 3600 &
[1] 2225
pax> sleep 3600 &
[2] 2226
pax> sleep 3600 &
[3] 2227
pax> sleep 3600 &
[4] 2228
pax> sleep 3600 &
[5] 2229
pax> kill $(ps aux | grep '[s]leep' | awk '{print $2}')
[5]+  Terminated              sleep 3600
[1]   Terminated              sleep 3600
[2]   Terminated              sleep 3600
[3]-  Terminated              sleep 3600
[4]+  Terminated              sleep 3600

and you can see it terminating all the sleepers.

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Explaining the grep '[p]ython csp_build.py' bit in a bit more detail:

When you do sleep 3600 & followed by ps -ef | grep sleep, you tend to get two processes with sleep in it, the sleep 3600 and the grep sleep (because they both have sleep in them, that's not rocket science).

However, ps -ef | grep '[s]leep' won't create a process with sleep in it, it instead creates grep '[s]leep' and here's the tricky bit: the grep doesn't find it because it's looking for the regular expression "any character from the character class [s] (which is s) followed by leep.

In other words, it's looking for sleep but the grep process is grep '[s]leep' which doesn't have sleep in it.

When I was shown this (by someone here on SO), I immediately started using it because

• it's one less process than adding | grep -v grep; and
• it's elegant and sneaky, a rare combination :-)

How to kill all processes matching a name?

From man 1 pkill

-f     The pattern is normally only matched against the process name.
       When -f is set, the full command line is used.

Which means, for example, if we see these lines in ps aux:

apache   24268  0.0  2.6 388152 27116 ?        S    Jun13   0:10 /usr/sbin/httpd
apache   24272  0.0  2.6 387944 27104 ?        S    Jun13   0:09 /usr/sbin/httpd
apache   24319  0.0  2.6 387884 27316 ?        S    Jun15   0:04 /usr/sbin/httpd

We can kill them all using the pkill -f option:

pkill -f httpd

How to run two process independently with their own thread pool and other configuration?

There is a clear violation of DRY (Don't Repeat Yourself) principle in your code.

In other words, there is lots of Boilerplate code in your Process and Main classes which can be eliminated by using the abstract classes (or use interfaces if you use Java8 with default methods).

So I have created two Process and ProcessHandler abstract classes to reuse the code which is common across each process and process handling.
So now, you can define ProcessA, ProcessB classes which extend Process and ProcessHandlerA, ProcesshandlerB which extend ProcessHandler class.

The key point is this solution can be extended to any number of Process **, i.e., this follows **Open/Closed principle of OOP.

You can refer the below code with comments:

Process class (abstract):

public abstract Process implements Runnable {

        private final Properties props;
        private final String processName;

        public Process(String processName, Properties props) {
            this.processName = processName;
            this.props = props;
        }

        //this can also be a non abstract (reusable) method 
        // to eliminate boiler plate code (if any)
        public abstract void shutdown();
    }

ProcessA class:

public class ProcessA extends Process {

          public ProcessA(String processName, Properties props) {
              super(processName, props);
          }

          @Override
          public void run() {
              //add run code here
          }

          @Override
          public void shutdown() {
              //shut down code
          }
    }

Process B class:

//Similar to ProcessA with specific details of B

ProcessHandler class (abstract):

public abstract class ProcessHandler {

         private final ExecutorService executorServiceProcess;
         private final List<Process> processList;
         private int poolSize;

         protected ProcessHandler(int poolSize) {
             executorServiceProcess = Executors.newFixedThreadPool(poolSize);
             processList = new ArrayList<>();
             this.poolSize = poolSize;
         }

          public void postInit(Process process) {
             for (int i = 0; i < poolSize; i++) {
                    processList.add(process);
                    executorServiceProcess.submit(process);    
              }  
          }

         public void shutdown() {
                Runtime.getRuntime().addShutdownHook(new Thread() {
                @Override
                public void run() {
                    for (Process process : processList) {
                      process.shutdown();
                    }
                    executorServiceProcess.shutdown();
                    try {
                      executorServiceProcess.
                        awaitTermination(1000, TimeUnit.MILLISECONDS);
                    } catch (InterruptedException ex) {
                      Thread.currentThread().interrupt();
                    }
                  }
                });
         }
 }

ProcessHandlerA class:

public class ProcessHandlerA extends ProcessHandler {

          public ProcessHandlerA() {
              super(3);//configure pool size properly w.r.to ProcessA requirements
          }

          public void postInit() {
              ProcessA processA = new ProcessA("processA", properties);
              super(processA);
          }

          public void shutdown() {
              super.shutdown();
          }
     }

ProcessHandlerB class:

//Similar to ProcessHandlerA with specific details for B

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