What to do if the linux top command cannot be used

The Linux top command cannot be used because the top command is not installed in the system. The solution is to install the top command through the "apt-get install procps" or "yum install procps" command.

The operating environment of this tutorial: linux5.9.8 system, DELL G3 computer

What should I do if the linux top command cannot be used?

Solution:

top command displays or manages executing programs.

top command installation:

-bash: top: command not found
 
#Debian
apt-get install procps
 
#Ubuntu
apt-get install procps
 
#Alpine
apk add procps
 
#Arch Linux
pacman -S procps-ng
 
#Kali Linux
apt-get install procps
 
#CentOS
yum install procps
 
#Fedora
dnf install bro-devel
 
#Raspbian
apt-get install procps
 
#Docker
docker run cmd.cat/top top

top command supplementary description:

top command provides a dynamic real-time view of the running system. It can display system summary information, as well as a list of processes or threads currently being managed by the kernel. The type, order, and size of system summary information displayed, as well as the information displayed for tasks, are user-configurable.

The top command can dynamically view the overall operation of the system in real time. It is a practical tool that integrates multi-party information monitoring system performance and operation information. The interactive interface provided by the top command can be managed using hotkeys.

top command syntax:

top -hv | -bcHisS -d delay -n limit -u|U user | -p pid -w [cols]

top command options:

-b：以批处理模式操作；
-c：显示完整的治命令；
-d：屏幕刷新间隔时间；
-I：忽略失效过程；
-s：保密模式；
-S：累积模式；
-i<时间>：设置间隔时间；
-u<用户名>：指定用户名；
-p<进程号>：指定进程；
-n<次数>：循环显示的次数。

top interactive commands:

Some interactive commands that can be used during the execution of the top command . These commands are single-letter, and some of them may be blocked if the -s option is used on the command line.

h：显示帮助画面，给出一些简短的命令总结说明；
k：终止一个进程；
i：忽略闲置和僵死进程，这是一个开关式命令；
q：退出程序；
r：重新安排一个进程的优先级别；
S：切换到累计模式；
s：改变两次刷新之间的延迟时间（单位为s），如果有小数，就换算成ms。输入0值则系统将不断刷新，默认值是5s；
f或者F：从当前显示中添加或者删除项目；
o或者O：改变显示项目的顺序；
l：切换显示平均负载和启动时间信息；
m：切换显示内存信息；
t：切换显示进程和CPU状态信息；
c：切换显示命令名称和完整命令行；
M：根据驻留内存大小进行排序；
P：根据CPU使用百分比大小进行排序；
T：根据时间/累计时间进行排序；
w：将当前设置写入~/.toprc文件中。

top Command Example:

top Command The first thing I look at is the load average, which is in the upper right corner of the screen.

top - 12:08:45 up 33 days,  1:54,  1 user,  load average: 0.08, 0.06, 0.07
 
Tasks: 135 total,   1 running, 134 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.1 us,  0.1 sy,  0.0 ni, 99.8 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem :  8008852 total,   230652 free,  1469292 used,  6308908 buff/cache
KiB Swap:        0 total,        0 free,        0 used.  5702188 avail Mem
 
  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                                                              
 1324 mysql     20   0 2636652 515728   8364 S   0.0  6.4  42:18.91 mysqld                                                                                                                               
 3282 root      20   0  775876 127856   4448 S   0.0  1.6  62:03.92 jcloudhids                                                                                                                           
 8572 nginx     20   0   80604  28032   2876 S   0.0  0.4   4:01.75 nginx                                                                                                                                
 8571 nginx     20   0   80432  27916   2872 S   0.0  0.3   2:50.95 nginx                                                                                                                                
 8570 nginx     20   0   80096  27636   2860 S   0.0  0.3   2:11.52 nginx                                                                                                                                
 8574 nginx     20   0   80128  27592   2860 S   0.0  0.3   1:50.45 nginx                                                                                                                                
 8569 nginx     20   0   80000  27360   2860 S   0.0  0.3   1:22.07 nginx                                                                                                                                
 8567 nginx     20   0   79992  27340   2868 S   0.0  0.3   1:31.04 nginx                                                                                                                                
 8568 nginx     20   0   79776  26988   2448 S   0.0  0.3   1:26.74 nginx                                                                                                                                
 8573 nginx     20   0   79756  26984   2456 S   0.0  0.3   1:37.43 nginx                                                                                                                                
  804 root      20   0  445200  24152    644 S   0.3  0.3  25:55.03 memcached                                                                                                                            
11255 nginx     20   0  340444  19900   5740 S   0.0  0.2   0:03.93 php-fpm                                                                                                                              
 7525 nginx     20   0  340332  19744   5744 S   0.0  0.2   0:03.97 php-fpm

Pay attention to the area: "Cpu(s):" This line is in the middle of the header information. In particular, I'm interested in %us, sy%, %id, and %wa, which are user processes, system processes, idle time, and the proportion of time the CPU spends waiting for I/O streams to execute, respectively. This percentage should be close to 0, and anything above 5% needs to be watched closely.

top - 12:08:45[当前系统时间],
33 days[系统已经运行了33天],
1 user[个用户当前登录],
load average: 0.08, 0.06, 0.07[系统负载，即任务队列的平均长度]
 
Tasks: 135 total[总进程数],
1 running[正在运行的进程数],
134 sleeping[睡眠的进程数],
0 stopped[停止的进程数],
0 zombie[冻结进程数],
 
Cpu(s): 
0.1%us[用户空间占用CPU百分比],
0.1%sy[内核空间占用CPU百分比],
0.0%ni[用户进程空间内改变过优先级的进程占用CPU百分比],
0.2%id[空闲CPU百分比], 
0.0%wa[等待输入输出的CPU时间百分比],
0.0%hi[],
0.0%st[],
Mem: 8008852k total[物理内存总量],
1469292k used[使用的物理内存总量],
230652k free[空闲内存总量],
158188k buffers[用作内核缓存的内存量]
Swap: 0k total[交换区总量],
0 used[使用的交换区总量],
0 free[空闲交换区总量],
0 cached[缓冲的交换区总量]

Recommended learning: "Linux Video Tutorial"

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