Every system administrator likes to use some of the more commonly used commands. Today I recommend htop as an alternative to the top command. To use the htop command usually, you need to install it first.
The top 0 and 1 indicate the number of your CPU cores, and the percentage indicates the occupancy rate of a single core (of course, the total occupancy rate of the CPU can also be displayed)
The different colors of the progress bar indicate the percentage of different process types:
Color
Description
Names displayed in other styles
Blue
Percentage of CPU used by low-priority processes
low
Green
Percentage of process CPU owned by ordinary users
Red
Percentage of CPU used by system processes
sys
Cyan
Percentage of CPU consumed by Steal Time
vir
Tasks: 22, 46thr, 174 kthr 1 running. In my example, it means that my current machine has 22 tasks, which are divided into 46 threads, of which only 1 process is in a running state, "kthr" indicates how many kernel threads there are.
Mem information. Similarly, use different colors to distinguish:
Color
Description
Names displayed in other styles
Blue
Percentage of memory consumed by the buffer
buffers
Green
Percentage of memory consumed by the memory area
used
Yellow/Orange
Percentage of memory consumed by the cache area
cache
Magenta
Percentage of memory occupied by shared memory area
shared
Swap information.
Color
Description
Names displayed in other styles
Green
Percentage of swap consumed by the swap area
used
Yellow/Orange
Percentage of swap consumed by the cache area
cache
Load average, the three values respectively represent the average load of the system in the last 1 minute, the last 5 minutes, and the last 15 minutes
Uptime, which means the running time after booting
PRI - Displays the process priority as seen by the Linux kernel
NI - Displays the process priority of reset by normal user or root super user
VIRT - Virtual memory being consumed by a process
RES - Physical memory being consumed by a process
SHR - Shared memory being consumed by a process
S - The current state of the process, there is a special state to pay attention to! That is Z (zombie process). When there are a large number of zombie processes in the machine, it will affect the performance of the machine.
CPU% - Percentage of CPU consumed by each process
MEM% - Percentage of memory consumed by each process
TIME+ - Shows the running time since the process was started
Command - The command corresponding to the process
In the interactive interface, press the F1 button to see the corresponding shortcut key description.
The up, down, left, and right direction keys can scroll through the interactive interface, and Space can mark the corresponding process, which is marked in yellow.
The N button, the P button, the M button and the T button are respectively PID, CPU%, MEM%, TIME+ is used for sorting. Of course, you can also use the mouse to click to sort in ascending or descending order of a certain field.
To manage the process, use the F9 button to send different signals to the process. The list of signals can be found in kill -l. The more commonly used ones are:
Signal
Description
1
Lets the process shut down immediately, and then restart after re-reading the configuration file
9
Used to immediately end the running of the program, used to forcibly terminate the process, similar to the forced end in the windows taskbar
15
The default signal for the kill command. Sometimes if a problem has occurred in the process and the process cannot be terminated normally with this signal, we will try signal 9
htop is much easier to use than the top that comes with the system, it is more intuitive, and it improves daily use greatly. This is why htop is usually one of the first packages the author installs after installing a new operating system.