# show memory usage in megabytes
$ free -m
total used free shared buff/cache available
Mem: 3788 1955 241 190 1592 1594
Swap: 0 0 0
# access memory raw data
$ cat /proc/meminfo
MemTotal: 3879924 kB
MemFree: 247836 kB
MemAvailable: 1633344 kB
Buffers: 3108 kB
Cached: 1567648 kB
SwapCached: 0 kB
Active: 2850928 kB
Inactive: 579040 kB
Active(anon): 1954152 kB
Inactive(anon): 100056 kB
Active(file): 896776 kB
Inactive(file): 478984 kB
...