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, the System V style and BSD style, PS aux was originally used in the Unix style, and ps-ef is used in the 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 user name
PID//Process ID
PPID//Parent process ID
C//Percentage of CPU consumed by process
Stime//Process start to present time
TTY//The process runs on that terminal, if it is not related to the terminal, then display? For pts/0, this means that 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
Percentage of CPU%CPU//process occupied
%MEM//Percentage of memory occupied
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 startup time
Time//When the process actually uses the CPU to run
Where the stat status bit common state characters have
D//The dormant state (usually IO process) that cannot be interrupted;
R//Is running can be in the queue can be over line;
S//in hibernation;
T//stop or be traced;
W//Enter memory swap (invalid starting from kernel 2.6);
X//Dead process (basic rarely seen);
Z//Zombie process;
<//high-priority processes
N//low-priority processes
L//Some pages are locked into memory;
S//Leader of the process (under it there are sub-processes);
L//multi-threaded, clone thread (using Clone_thread, similar to NPTL pthreads);
+//Process group in the background;
The difference and format of ps-ef and PS aux under Linux