Differences and formats between ps-ef and ps aux in Linux

Differences and formats between ps-ef and ps aux in Linux

In Linux, the command ps of the system process is displayed. The most common Commands include ps-ef and ps aux. What are the differences between the two? There is no big difference between the two. to discuss this issue, we need to trace the two styles in Unix systems: System V and BSD. ps aux was originally used in Unix styles, ps-ef is used in System V Style, and their output is slightly different. Currently, most Linux systems can use both of these methods.

Ps-ef displays processes in the standard format. The format is as follows:

The content of each column is as follows:
UID // user ID, but the output is the user name
PID // process ID
PPID // parent process ID
C // percentage of CPU used by processes
STIME // The time when the process has been started
TTY // which terminal does the process run? If it is pts/0, it indicates that the network is connected to the host process.
CMD // command name and Parameters

Ps aux is displayed in BSD format. Its format is as follows:

Different columns from ps-ef have
USER // USER Name
% CPU // percentage of CPU used by the Process
% MEM // percentage of memory occupied
VSZ // virtual content used by the process (KB)
RSS // fixed content occupied by the process (KB) (number of resident pages)
STAT // Process status
START // START time when the process is triggered
TIME // The actual CPU running TIME of the process

Among them, the common status characters of the STAT status bit are:
D // a sleep state that cannot be interrupted (usually an IO process );
R // It is running and can be crossed in the queue;
S // in sleep state;
T // stop or be tracked;
W // enter the memory switch (it is invalid from kernel 2.6 );
X // dead process (rarely seen );
Z // zombie process;
<// Process with a higher priority
N // process with lower priority
L // some pages are locked into the memory;
S // process leader (under it there are sub-processes );
L // multithreading, clone the thread (using CLONE_THREAD, similar to NPTL pthreads );
+ // Process group in the background;

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