Check if process is running on windows/linux

Question

i have a process

Runtime rt = Runtime.getRuntime() ;
Process p = rt.exec(filebase+port+"/hlds.exe +ip "+ip+" +maxplayers "+players+ " -game cstrike -console +port "+port+" -nojoy -noipx -heapsize 250000 +map de_dust2 +servercfgfile server.cfg +lservercfgfile +mapcyclefile mapcycle.txt +motdfile motd.txt +logsdir logs -zone 2048",null,  new File(filebase+port)) ;

i want to keep a check on this process whether its running or has crashed in case of crash want to restart it, this Process can have multiple instance available depending upon the port

Can i trace this thing on Linux as well as on windows? Read some articles on it but this 1 is bit different, since it involves multiple occurrences and have to check on some particular process only

Answer 1

You can do a p.waitFor() so the thread that executed the statement waits till the process is complete. You can then do the cleanup/restart logic right after, as that code will get executed when the process dies. However I am not sure how this would work if the process hangs instead of dying, but this could be worth a try. By the way I would recommend using Java Service Wrapper and supervisord in your case if this is something you're going to do on production.

Answer 2

boolean isRunning(Process process) {
    try {
        process.exitValue();
        return false;
    } catch (Exception e) {
        return true;
    }
}

See http://docs.oracle.com/javase/6/docs/api/java/lang/Process.html#exitValue()

Answer 3

As of Java 8 you can do:

process.isAlive()