Using PHP (may be commandline using shell_exec() function), how can I determine if a Java application/jar file is currently running or not?

Question

I have a PHP application which executes a Java .jar file through shell_exec() :

shell_exec("java jar myJarProgram.jar");

I have a need to determine if an instance this java program myJarProgram.jar is already running, because if it is not, then I can start it using the above PHP statement.

How can I do that?

Answer 1

您可以使用“ jps”实用程序使用Java来复制您的进程

jps -mlvV | grep myJarProgram.jar

Answer 2

jps is a good candidate for this, but please note that

To use the jps command-line tool you need to install a JDK.

Otherwise, you can parse the output of another shell_exec call that uses ps with the arguments you want in order to get the running processes: at this point you can check if the process is present.

$search_string = "[j]ava jar myJarProgram.jar"; $running = shell_exec("ps -A -ww | grep '$search_string'"); or similar.

If $running is empty, you can launch the jar.

Another option is to perform everything with a single shell_exec , both with commands concatanation (simple && and || ) or creating a .sh script and shell_exec uting that.

EDIT: According to the user comment, the script must work both for Windows and Linux. You can use the php PHP_OS predefined constant to check if it's Windows or Linux:

if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') etc....

If it's Linux, you can use the shell_exec as reported above. If it's Windows, you can change the shell_exec string using the tasklist Windows command. I don't know it, but there are already dedicated questions and answers like this one .