The docker ps command, which is available inside the container, is used to see the status of the process. This is similar to the standard ps command in the Linux environment and is not a docker ps command that we run on the Docker 
host machine.

This command runs inside the Docker container:

root@5562f2f29417:/# ps -s
UID   PID   PENDING   BLOCKED   IGNORED    CAUGHT STAT TTY         TIME COMMAND
0     1  00000000  00010000  00380004  4b817efb Ss   
?           0:00 /bin/bash
0    33  00000000  00000000  00000000  73d3fef9 R+   ?           0:00 ps -s
root@5562f2f29417:/# ps -l
F S   UID   PID  PPID  C PRI  NI ADDR SZ WCHAN  TTY          TIME CMD
4 S     0     1     0  0  80   0 -  4541 wait   ?        00:00:00  bash
root@5562f2f29417:/# ps -t
PID TTY      STAT   TIME COMMAND
  1 ?        Ss     0:00 /bin/bash
 35 ?        R+     0:00 ps -t
root@5562f2f29417:/# ps -m
PID TTY          TIME CMD
  1 ?        00:00:00 bash
  - -        00:00:00 -
 36 ?        00:00:00 ps
  - -        00:00:00 -
root@5562f2f29417:/# ps -a
PID TTY          TIME CMD
 37 ?        00:00:00 ps 

Use ps --help <simple|list|output|threads|misc|all> or ps --help <s|l|o|t|m|a> for additional help text.