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POperl: Launch process with system(), then check if its running under a specific display number
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copied!<p>I have a locked down "kiosk" terminal server.</p> <p>This terminal server has a perl script as its .Xsession, and launches a Tk interface. When that Tk interface is done, the perl script launches "process2" and lets the user interact with "process2" (which is a graphical application).</p> <p>If a user tampers with "process2", and make it crash, the user might be able to access the underlying desktop, therefore I would want to check if "process2" is running, and if "process2" is not running on $display, I would want to just execute logout (which would logout the display the perl script is currently running as).</p> <p>Since the system is running 10 instances of "process2" to 10 different users simultanuosly, I cant just check if "process2" is running on the system with "ps" or someting like that. I need to check if "process2" is running under that specific display $display. Note that all 10 users log on as the same username in all sessions, so I cannot check all processes run by a specific user, that would return all 10 instances too.</p> <p>Like:</p> <pre><code>system("process2 &"); while(1) { sleep(1); if (is_it_running("process2", $display) == false) { system("logout &"); } } </code></pre> <p>Its the function "is_it_running" that I need to get to know how it should look. $display can either contain the raw display number, like this: ":1.0", or it can contain the display number parsed out, like this: "1".</p>

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