Implemented by the procps package on Ubuntu 14.04.
Print RAM and swap memory in Megabytes:
free
Sample output:
total used free shared buffers cached
Mem: 3767368 3629844 137524 457068 30312 1098720
-/+ buffers/cache: 2500812 1266556
Swap: 3910652 445044 3465608
-h: human readable output:
total used free shared buffers cached
Mem: 3.6G 3.4G 172M 451M 29M 1.0G
-/+ buffers/cache: 2.4G 1.2G
Swap: 3.7G 434M 3.3G
Other flags:
-s1, -s0.01: repeat every N seconds. ms resolution.