To kill a process use command, extend with different signal numbers, command : kill -SIGNAL PID
Process signal names and numbers: process kill methods mentioned below,to see all signals run : kill -l
| Signal Names mostly used | Signal Number | Signal Use |
| SIGNULL | 0 | NULL, check access to PID |
| SIGHUP | 1 | Hangup |
| SIGINT | 2 | Interrupt |
| SIGQUIT | 3 | Quit |
| SIGKILL | 9 | Kill |
| SIGTERM | 15 | Terminate |
| SIGSTOP | 24 | Stop |
| SIGTSTP | 25 | Stop/pause the process |
| SIGCONT | 26 | Continue a stopped process |
| 1 | kill -SIGNAL PID | Kill -9 1002 | Command to kill process |
| 2 | kill -SIGNAL PID PID | Kill -9 1002 1003 | Command to kill multi process |
Regular/Real time we mostly check real time activities and memory usage using top command,
| top – 03:43:03 up 1 day, 2:00, 3 users, load average: 0.00, 0.00, 0.00
Tasks: 94 total, 1 running, 56 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.0 us, 0.0 sy, 0.0 ni, 99.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.3 st KiB Mem : 1005836 total, 701520 free, 94628 used, 209688 buff/cache KiB Swap: 0 total, 0 free, 0 used. 767308 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND . 1 root 20 0 123484 5392 3852 S 0.0 0.5 0:03.75 systemd 2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd 4 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/0:0H 5 root 20 0 0 0 0 I 0.0 0.0 0:00.39 kworker/u30:0 |