free Command:free is the most commonly used command for checking the memory usage of a Linux system. It displays information about the total, used, and free memory.

top Command

The simplest way to check the RAM memory usage is to display the contents of the /proc/meminfo virtual file. This file is used by the free, top, ps , and other system information commands.

ps_mem Script

output in bytes

output in kibibytes

output in mebibytes

 Display System Memory

 Display Memory in Gigabytes

Display Total Line

Display Memory Status for Regular Intervals

Show Low and High Memory Statistics

Check Free Version

Showing the Column Totals

Showing Memory Usage in Other Metrics

by using -h option shows the output in human readable format

by using free command we see the results for total, used and free memory on system by accessing the system kernel. it also displays the shared cache and available 

it will show us onnly one output and this output will be changing at regular intervals

-s option is used to instriuts free command to refresh the puput for every 3 sec. to stop th process ctrl+c

gives the output in mebibytes

use the si the power 1024 and in megabytes

-c option instructs the free command to automatocally quit after refreshing 4 times

to see the buffer and cache colums seperatly

total option instructs free to show the toatal memory of used,free total columns of memory and swap columns

the command produces ouput in mebibytes with 3 seconds delay and quits after refreshing the ouput for 4 times