Tracking Processes In UNIX/LINUX System

In Linux (and UNIX in general), each program which is running comprises a process.From the operating system’s point of view, each process is independent of the others. Unless it specifically asks to share resources with other processes, a process is confined to the memory  and CPU allocation assigned to it. If a Process oversteps its memory allocation and could corrupt another running program and make the system unstable are immediately killed by Linux. This method of handling processes has resulted as a major contributor to the stability of UNIX/LINUX systems: User applications cannot corrupt other user programs or the operating system.
                    There are tools provided by which you can manually list and manipulate processes. These are very important elements of a system administrator’s daily work.
        
Command used for Listing Processes: ps
               The ps command lists all the processes in a system, their state, size, name, owner, CPU time, wall clock time, and much more. There are many command-line parameters available; the majoy one are

Options for ps	Description
–a	Shows all the processes with a controlling terminal and not just the current user’s processes.
–r	Show only running processes
–x	Show processes that do not have a controlling terminal.
–u	Show the process owners.
–f	Display parent/child relationships among processes.
–l	Produce a list in long format.
–w	Shows a process command-line parameters (up to half a line).
–ww	Show all of a process’s command-line parameters.

        The most commonly used parameters used with ps command is –auxww. These parameters show all the processes (regardless of whether they have a controlling terminal),each process’s owners, and all the processes’ command-line parameters.