linux/ubuntu 中的总体 CPU 使用率和内存（RAM）使用率百分比

Question

I want to findout overall CPU usage and RAM usage in percentage, but i dint get success

$ command for cpu usage
4.85%

$ command for memory usage
15.15%

OR

$ command for cpu and mamory usage
cpu: 4.85%
mem: 15.15%

How can I achieve this?

Answer 1

You can use top and/or vmstat from the procps package. Use vmstat -s to get the amount of RAM on your machine (optional), and then use the output of top to calculate the memory usage percentages.

%Cpu(s):  3.8 us,  2.8 sy,  0.4 ni, 92.0 id,  1.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem : 24679620 total,  1705524 free,  7735748 used, 15238348 buff/cache
KiB Swap:        0 total,        0 free,        0 used. 16161296 avail Mem 

You can also do this for relatively short output:

watch '/usr/bin/top -b | head -4 | tail -2'

A shell pipe that calculates the current RAM usage periodically is

watch -n 5 "/usr/bin/top -b | head -4 | tail -2 | perl -anlE 'say sprintf(\"used: %s   total: %s  => RAM Usage: %.1f%%\", \$F[7], \$F[3], 100*\$F[7]/\$F[3]) if /KiB Mem/'"

(CPU + Swap usages were filtered out here.)

This command prints every 5 seconds:

Every 5.0s: /usr/bin/top -b | head -4 | tail -2 | perl -anlE 'say sprintf("u...  wb3: Wed Nov 21 13:51:49 2018

used: 8349560   total: 24667856  => RAM Usage: 33.8%

Answer 2

Please use one of the following:

$ free -t | awk 'NR == 2 {print "Current Memory Utilization is : " $3/$2*100}'
Current Memory Utilization is : 14.6715

OR

$ free -t | awk 'FNR == 2 {print "Current Memory Utilization is : " $3/$2*100}'
Current Memory Utilization is : 14.6703

Answer 3

CPU usage => top -bn2 | grep '%Cpu' | tail -1 | grep -P '(....|...) id,' | awk '{print 100-$8 "%"}' top -bn2 | grep '%Cpu' | tail -1 | grep -P '(....|...) id,' | awk '{print 100-$8 "%"}'

Memory usage => free -m | grep 'Mem:' | awk '{ print $3/$2*100 "%"}' free -m | grep 'Mem:' | awk '{ print $3/$2*100 "%"}'

Answer 4

For the cpu usage% you can use:

top -b -n 1| grep Cpu | awk -F "," '{print $4}' | awk -F "id" '{print $1}' | awk -F "%" '{print $1}'

Answer 5

One liner solution to get RAM % in-use:

free -t | awk 'FNR == 2 {printf("%.0f%"), $3/$2*100}'

Example output: 24%

for more precision, you can change the integer N inside printf(%.<N>%) from the the previous command. For example to get 2 decimal places of precision you could do:

free -t | awk 'FNR == 2 {printf("%.2f%"), $3/$2*100}'

Example output: 24.57%