Process management command
init: Process number is 1
Classification of processes:
the processes associated with the terminal
Terminal independent process
1.process state:
D: Non interrupted sleep
R: Run or ready
S: Interrupted sleep
T: Stop it
Z: Zombie state
<: High priority process
N: Low priority process
+: Processes in the foreground process group
l: Multi thread processes
s: The first process of the session
2.process command
ps -aux
ps: Process State
SysV:-
BSD:
a:All the processes associated with the terminal
u:the processes created by the current user
x:All the processes that are not related to the terminal
ps
-elF
-ef
-eF
ps -o property1,property2
eg. ps -o pid,comm,ni
pstree: Display process tree
pgrep
pidof: Find the ID number according to the process name
top:
M: Sort the dwell memory size
P:Sort by using the percentage of CPU
T: Sort by the total time
l: Whether the average load and start time are displayed
t: Whether the display process and CPU status information
m:Display memory related information
c: Display complete command line information
q: exit top
k: To terminate a process
top
-d: Long latency , unit is second
-b: Batch mode
-n #:In batch mode,Show how many batches
Important signal:
1:SIGHUP: Let a process not restart,You can read the configuration file,And let the new configuration information come into effect
2:SIGINT: Ctrl+c: Interrupt a processes
9:SIGKILL:Kill a processes
15:SIGTERM:Terminate a process(Default signal)
kill PID
killall COMMAND
send a signal:
by Signal number:kill -1
by signal name:kill -SIGKILL
by Signal for short:kill -KILL
Foreground-->Background:
Ctrl+z: Send the job to the background in the foreground.
COMMAND &:Let the command execute in the background.
bg:Let the background of the job to continue to run
bg [%JOBID]
jobs: See all of the work in the background.
job ID,not is pid
fg: The background work to the Foreground
fg [%JOBID]
kill %JOBID: Terminate a job
vmstat:System status view command
uptime: View system load