Linux Learning Note 4

Process

1. What is a process
   Process is what the system is doing
   
   2. Process status
   Run
   Dormancy
   Stop it
   Go on
   End
   Zombie Process
   
   3. How to view processes in a drawing
   Gnome-system-monitor
   
   4. How to view processes with commands
   PS Process Viewing tool
   -a process running in shell
   -X processes that are not running in the shell
   -U View Process user
   -L Display Process details
   -F Full info abbreviation
   -e Displays all processes in the system
   
   Ps-aux |grep Process keyword
   
   PS Ax-o%cpu,%mem,user,comm,nice View process information (CPU Memory user command Priority)
   PS aux--sort +|-%cpu|%mem ... The process is sorted by the specified mode
   
   5. How to control the front and back calls of the shell heavy process
   
   Commands & processes run in shell background
   CTRL +z the shell-hogging process into the background stop
   Jobs view process information in the background
   FG Job (number) to bring the specified process back to the foreground
   BG Job (number) running background stop process
   CTRL +c close the shell process
   6. How to control processes with commands
   
   1) Signal
   Signal 1 Reload Process
   Signal 2 CTRL +C Delete the information in memory of the process
   Signal 3 in-memory mouse message cleanup
   Signal 9 forcibly shuts down the process (only the current program is closed and the subroutine is not closed)
   Signal 15 normal shutdown process
   Signal 18 turn on the stopped process
   Signal 19 Stop a running process
   Signal Ctrl +Z (background and run)
   
   2) Signal Initiation
   Kill Signal PID
   Killall Signal Process Name
   Pkill-u username End All processes for a user

   
   

   
   

W View users currently using the system

W-f View the user who is currently using the system and show where to use it

Last view users logged in the system

LASTB viewing users attempting to log on but not successful

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Service

1. What is a service?
   Service
   Service is the software running in the system, this software is mainly to provide a function, then we call this kind of software service
   
   
   2. Service Management, Systemctl command
   Systemctl Start Service Name Open service
   Stop .... Close Service
   Restart .... Restart Service
   Reload .... Re-add the service configuration
   Status .... View service Status
   Enable .... Set up service boot
   Disable .... Disable service boot start
   List-dependencies View service Dependencies
   List-units to view all currently running services
   List-unit-files viewing the start-up of a service
   Set-default multi-user.target boot Not start graphics
   Set-default Graphical.target boot up graphics

Linux Learning Note 4