Explanation of the parameters of ps command ps -aux and ps -ef in Linux

1. ps command

The ps command is used to display the status of the current process, similar to the task manager of windows.

1.1 ps-aux

Reference materials: Linux ps command | rookie tutorial (runoob.com)

• command explanation

显示所有包含其他使用者的进程

• Output format of ps -aux

USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND

• parameter explanation

  • USER: the process owner
  • PID: pid
  • %CPU: occupied CPU usage
  • %MEM: occupied memory usage
  • VSZ: virtual memory size occupied
  • RSS: memory size occupied
  • TTY: minor device number of tty
  • STAT: Status of the trip:
    • D: Uninterruptible sleep state (usually IO process)
    • R: in progress
    • S: static state
    • T: suspend execution
    • Z: does not exist but cannot be eliminated temporarily
    • W: not enough memory pages to allocate
    • <: high priority itinerary
    • N: low priority itinerary
    • L: Memory paging is allocated and locked in memory (real-time system or AI/O)
  • START: Trip start time
  • TIME: execution time
  • COMMAND: the command executed

• example

  • view all processes

  [root@localhost ~]# ps -aux
  USER        PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
  root          1  0.0  0.1 191412  4400 ?        Ss   19:03   0:02 /usr/lib/systemd/systemd --switched-root --system --deserialize 22
  root          2  0.0  0.0      0     0 ?        S    19:03   0:00 [kthreadd]
  root          4  0.0  0.0      0     0 ?        S<   19:03   0:00 [kworker/0:0H]
  root          6  0.0  0.0      0     0 ?        S    19:03   0:00 [ksoftirqd/0]
  root          7  0.0  0.0      0     0 ?        S    19:03   0:00 [migration/0]
  root          8  0.0  0.0      0     0 ?        S    19:03   0:00 [rcu_bh]
  root          9  0.0  0.0      0     0 ?        S    19:03   0:00 [rcu_sched]
  root         10  0.0  0.0      0     0 ?        S<   19:03   0:00 [lru-add-drain]
  

  

  • Find the specified process

  [root@localhost ~]# ps -aux | grep tail
  tom        3869  0.0  0.0 108304   680 pts/2    S+   20:10   0:00 tail
  root       3872  0.0  0.0 112824   980 pts/1    R+   20:10   0:00 grep --color=auto tail
  

  

1.2 ps -ef

• command explanation

列出全部进程的全部信息

• Output format of ps -ef

UID         PID   PPID  C STIME TTY          TIME CMD

• parameter explanation

  • UID: the user ID to which the process belongs
  • PID: Process ID of the process
  • PPID: The parent ID of the process (other processes that started this process)
  • C: CPU usage of this process (percentage)
  • STIME: The start time of the process
  • TTY: The serial number of the terminal that started this process, if it displays ?, it means that it is not started by a terminal
  • TIME: The time the process occupies the CPU
  • CMD: the name corresponding to the process or the startup path or the startup command

• example

  • view progress

  [root@localhost ~]# ps -ef
  UID         PID   PPID  C STIME TTY          TIME CMD
  root          1      0  0 19:03 ?        00:00:02 /usr/lib/systemd/systemd --switched-root --system --deserialize 22
  root          2      0  0 19:03 ?        00:00:00 [kthreadd]
  root          4      2  0 19:03 ?        00:00:00 [kworker/0:0H]
  root          6      2  0 19:03 ?        00:00:00 [ksoftirqd/0]
  root          7      2  0 19:03 ?        00:00:00 [migration/0]
  root          8      2  0 19:03 ?        00:00:00 [rcu_bh]
  root          9      2  0 19:03 ?        00:00:00 [rcu_sched]
  root         10      2  0 19:03 ?        00:00:00 [lru-add-drain]
  

  

  • Find the specified process

  [root@localhost ~]# ps -ef | grep tail
  tom        3955   3827  0 20:18 pts/2    00:00:00 tail
  root       4010   3960  0 20:19 pts/3    00:00:00 tail
  root       4042   3065  0 20:21 pts/1    00:00:00 grep --color=auto tail