In computing, the process identifier (normally referred to as the process ID or just PID) is a number used by most operating system kernels (such as that of UNIX, Mac OS X or Microsoft Windows) to (temporarily) uniquely identify a process. This number may be used as a parameter in various function calls allowing processes to be manipulated, such as adjusting the process’s priority or killing it altogether (wikipedia).
From this post, I try to write how Qt with QProcess get PID. We can show QProces get PID with use command :
Q_PID QProcess::pid () const
This function will Returns the native process identifier for the running process, if available. If no process is currently running, 0 is returned. This is screenshot my program Qt : QProcess get PID :
From this program, we can type a name of a program and press button ‘Process’. If that program exist, this Qt : QProcess get PID will open that program and show PID from that program. We can check PID from this program from command line/konsole and type :
This is a screenshot of my computer from this command :
We can see, PID value from Qt : QProcess get PID is equal with PID from konsole command. You can get the complete source code from Qt : QProcess get PIDin here.