Linux Displays the system process command PS, the most commonly used are ps-ef and PS aux. What is the difference between the two? There is not much difference between the two, to discuss this issue, to go back to the UNIX system in the style of both
System V style and BSD style,PS aux was originally used in Unix style, and ps-ef is used in System V style, the output is slightly different. Most Linux systems today can be used in both ways.
PS-EF Displays the process in a standard format, with the following format
The contents of each column are as follows
UID // user ID, but output is username PID // process IDPPID // parent process IDC // process consumes percent of CPU stime // the time that the process started up to now TTY // The process runs on that terminal, and if it is not related to the terminal, it is displayed. If pts/0, the host process is connected by the network. CMD // command name and Parameters
PS aux is displayed in BSD format, and its format is as follows
Unlike Ps-ef, there are lists of
User // username %cpu // process occupied CPU percentage %MEM // % of memory consumed VSZ // The amount of virtual memory used by the process (KB)RSS // This process occupies a fixed amount of memory (KB) (number of pages residing in)STAT // status of the process START // The process is triggered by the start time Time // when the process actually uses the CPU to run
Where the stat status bit common state characters have
D//Unable to interrupt the sleep state (usually the IO process);R//running can be in the queue can be too line;S//in hibernation state;T//stop or be traced;W//Enter memory swap (invalid starting from kernel 2.6);X//the dead process (rarely seen);Z//zombie process;<//high-priority processesN//processes with lower priorityL//Some pages are locked into memory;S//leader of the process (under it there are sub-processes);L//multi-threaded, cloned threads (using Clone_thread, similar to NPTL pthreads);+//process groups located in the background;
The difference and format of ps-ef and PS aux under Linux