Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In computing, the process identifier (normally referred to as the process ID or just PID) is a number used by some operating system kernels (such as that of UNIX, Mac OS X or Microsoft Windows) to uniquely identify a process. This number may be used as a parameter in various functi ...Full description
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In computing, the process identifier (normally referred to as the process ID or just PID) is a number used by some operating system kernels (such as that of UNIX, Mac OS X or Microsoft Windows) to 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. In Unix-like operating systems, new processes are created by the fork() system call. The PID is returned to the parent enabling it to refer to the child in further function calls. The parent may, for example, wait for the child to terminate with the waitpid() function, or terminate the process with kill(). In Unix-like operating systems, there are two tasks with specially distinguished process IDs: swapper or sched has process ID zero and is responsible for paging, and is actually part of the kernel rather than a normal user-mode process.