Linux Process Management

Linux process Management is a function of the Linux kernel.

1.ps Command: Process state

SYSV style: Each option needs to add-
BSD style: Each option does not need to add-

        a：显示全部与终端有关的进程        u：        x：全部与终端无关的进程        -e：显示全部进程        -F：额外全然格式        -l：

2. Process classification:

Terminal-related processes
Terminal-independent processes

3. Process Status:

D: Non-disruptive sleep
R: Execute or ready
S: interruptible Sleep
T: Stop
Z: Zombies

<：高优先级进程N：低优先级进程+：前台进程组进程l：多线程进程s：会话进程

4.pstree: Show Process Tree

5.pgrep: Show process in grep style

6.pidof: Shows the PID of the program being executed

PIDOF Init
Pidof sshd

7.top:

M: Sort by resident memory size
P: Sort based on CPU percent usage
T: Sort According to cumulative time

l：是否显示平均负载和启动时间t：是否显示和CPU状态相关信息m：是否显示内存相关信息c：是否显示完整的命令行信息q：推出topk：终止某个进程-d：改变刷新延迟时长-b：以批模式显示-n #：批模式仅仅显示#批

8. Important Signals:

1:sighup: Allow a process to reread the configuration file without restarting, and let the new configuration information take effect;
2:sigint:ctrl + C, terminating
9:sigkill: Kill a process
15:sigterm: Terminates a process (default signal)

Specify a signal:
Signal Number: KILL-1
Signal Name: Kill-sigkill
Signal name shorthand: Kill-kill

9.killall command: Kills all processes named command

10. Adjust the Nice value:

To adjust the nice value of a process that has started:
Renice NI PID
Specify nice values at startup:
Nice-n NI COMMAND

11.vmstat: System Status View command

12. Front Desk –> Backstage:

Ctrl + Z
COMMAND &
BG: Let the background stop job continue execution

Jobs: View all jobs in the background
Work well, different from process number
+: Command will default action for jobs
-: command to assign a second default action to the job
FG: Returning a background job to the foreground again
FG [[%]jobid], the middle percent can be omitted, but assuming that the kill command is used, the% number must not be omitted, the default is to terminate the corresponding process, such as:
Kill 2 represents a process that kills a PID of 2. Instead of ending the job with job number 2.

Linux Process Management