free - Display amount of free and used memory in the system

$ free
             total       used       free     shared    buffers     cached
Mem:       2053440     522028    1531412          0      87076     265952
-/+ buffers/cache:     169000    1884440
Swap:      2441840          0    2441840
		

5秒监控一次

neo@neo-OptiPlex-780:~/workspace/Document$ free -s 5
             total       used       free     shared    buffers     cached
Mem:       2054224    1708876     345348          0      58908     696404
-/+ buffers/cache:     953564    1100660
Swap:      2077692      81948    1995744

             total       used       free     shared    buffers     cached
Mem:       2054224    1708876     345348          0      58908     696404
-/+ buffers/cache:     953564    1100660
Swap:      2077692      81948    1995744

             total       used       free     shared    buffers     cached
Mem:       2054224    1709000     345224          0      58908     696404
-/+ buffers/cache:     953688    1100536
Swap:      2077692      81948    1995744