current memory usage linux code example

Example 1: linux memory usage

// linux command for reporting used memory percentage
$ free | grep Mem | awk '{print $3/$2 * 100.0}'
23.8171

Example 2: linux show current memory usage

free
#------------------------------------------------------------
#total	Total installed memory
#used	Memory currently in use by running processes (used= total – free – buff/cache)
#free	Unused memory (free= total – used – buff/cache)
#shared	Memory shared by multiple processes
#buffers	Memory reserved by the OS to allocate as buffers when process need them
#cached	Recently used files stored in RAM
#buff/cache	Buffers + Cache
#available	Estimation of how much memory is available for starting new applications, without swapping.

Example 3: view memory usage linux

top - 15:20:30 up  6:57,  5 users,  load average: 0.64, 0.44, 0.33
Tasks: 265 total,   1 running, 263 sleeping,   0 stopped,   1 zombie
%Cpu(s):  7.8 us,  2.4 sy,  0.0 ni, 88.9 id,  0.9 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem:   8167848 total,  6642360 used,  1525488 free,  1026876 buffers
KiB Swap:  1998844 total,        0 used,  1998844 free,  2138148 cached

  PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND                                                                                 
 2986 enlighte  20   0  584m  42m  26m S  14.3  0.5   0:44.27 yakuake                                                                                 
 1305 root      20   0  448m  68m  39m S   5.0  0.9   3:33.98 Xorg                                                                                    
 7701 enlighte  20   0  424m  17m  10m S   4.0  0.2   0:00.12 kio_thumbnail