N days to learn the free of a Linux command

Use

View system memory (physical/virtual/cache/shared) usage

Usage

free [-b | -k | -m | -g | -h] [-o] [-s delay ] [-c count ] [-a] [-t] [-l] [-V]

Common options

Options	meaning	Description
-B	Unit byte	Switch displays the amount of memory in bytes;
-K	Unit K	Switch (set by default) displays it in kilobytes;
-M	Unit m	Switch displays it in megabytes;
-G	Unit g	Switch displays it in gigabytes;
-H	Human readable mode	Switch displays all output fields automatically scaled to the shortest (three digit) representation including the unit. That makes the values human readable.
-T	Show Total row of sinks	Switch displays a line containing the totals.
-O	Disables the display of a "buffer adjusted" line	Switch disables the display of a "buffer adjusted" line. If the-o option isn't specified, free subtracts buffer memory from the used memory and adds it to the free memory report Ed.
-S interval of seconds	Repeat refresh display at intervals of several seconds	Switch activates continuous polling delay seconds apart. Actually specify any floating point number for delay, Usleep (3) are used for microsecond resolution delay times.
-C Times	Total number of repeated refreshes displayed	Switch used together with THE-S switch interrupts the polling after count repetitions.
-L	Show Low Line	Switch shows detailed low and high memory statistics.
-A	Show available memory	Switch shows the available memory (if supported by the running kernel and enabled with Sysctl-w Vm.mem-info_legacy_layout =0; Shows zero when unsupported or disabled). The produced output is wider than characters.
-V	Display Program Version information	Switch displays version information.

Practice

1 Displaying memory usage

[[email protected] ~]# free -h             total       used       free     shared    buffers     cachedMem:          2.9G       2.7G       209M        37M        11M       185M-/+ buffers/cache:       2.5G       405MSwap:         1.6G       1.2G       415M

Resources

"1" Mans free
"2" one Linux command per day: free command
Http://www.cnblogs.com/peida/archive/2012/12/25/2831814.html
The free command on "3" Linux is detailed
Http://www.cnblogs.com/coldplayerest/archive/2010/02/20/1669949.html

N days to learn the free of a Linux command