[su-kaiyao]translating 10 ‘free’ Commands to Check Memory Usage in Linux ================================================================================ **Linux** is one of the most popular open source operating system and comes with huge set of commands. The most important and single way of determining the total available space of the **physical memory** and **swap memory** is by using “**free**” command. The Linux “**free**” command gives information about total used and available space of **physical memory** and **swap memory** with **buffers** used by kernel in **Linux/Unix** like operating systems. ![10 Linux Free Command Examples](http://www.tecmint.com/wp-content/uploads/2012/09/Linux-Free-commands.png) This article provides some useful examples of “**free**” commands with options, that might be useful for you to better utilize memory that you have. ### 1. Display System Memory ### Free command used to check the used and available space of **physical memory** and **swap memory** in **KB**. See the command in action below. # free total used free shared buffers cached Mem: 1021628 912548 109080 0 120368 655548 -/+ buffers/cache: 136632 884996 Swap: 4194296 0 4194296 ### 2. Display Memory in Bytes ### Free command with option **-b**, display the size of memory in **Bytes**. # free -b total used free shared buffers cached Mem: 1046147072 934420480 111726592 0 123256832 671281152 -/+ buffers/cache: 139882496 906264576 Swap: 4294959104 0 4294959104 ### 3. Display Memory in Kilo Bytes ### Free command with option **-k**, display the size of memory in (KB) **Kilobytes**. # free -k total used free shared buffers cached Mem: 1021628 912520 109108 0 120368 655548 -/+ buffers/cache: 136604 885024 Swap: 4194296 0 4194296 ### 4. Display Memory in Megabytes ### To see the size of the memory in **(MB) Megabytes** use option as **-m**. # free -m total used free shared buffers cached Mem: 997 891 106 0 117 640 -/+ buffers/cache: 133 864 Swap: 4095 0 4095 ### 5. Display Memory in Gigabytes ### Using **-g** option with free command, would display the size of the memory in **GB(Gigabytes)**. # free -g total used free shared buffers cached Mem: 0 0 0 0 0 0 -/+ buffers/cache: 0 0 Swap: 3 0 3 ### 6. Display Total Line ### Free command with -t option, will list the total line at the end. # free -t total used free shared buffers cached Mem: 1021628 912520 109108 0 120368 655548 -/+ buffers/cache: 136604 885024 Swap: 4194296 0 4194296 Total: 5215924 912520 4303404 ### 7. Disable Display of Buffer Adjusted Line ### By default the free command display “**buffer adjusted**” line, to disable this line use option as -o. # free -o total used free shared buffers cached Mem: 1021628 912520 109108 0 120368 655548 Swap: 4194296 0 4194296 ### 8. Dispaly Memory Status for Regular Intervals ### The -s option with number, used to update free command at regular intervals. For example, the below command will update free command every 5 seconds. # free -s 5 total used free shared buffers cached Mem: 1021628 912368 109260 0 120368 655548 -/+ buffers/cache: 136452 885176 Swap: 4194296 0 4194296 ### 9. Show Low and High Memory Statistics ### The -l switch displays detailed high and low memory size statistics. # free -l total used free shared buffers cached Mem: 1021628 912368 109260 0 120368 655548 Low: 890036 789064 100972 High: 131592 123304 8288 -/+ buffers/cache: 136452 885176 Swap: 4194296 0 4194296 ### 10. Check Free Version ### The -V option, display free command version information. # free -V procps version 3.2.8 -------------------------------------------------------------------------------- via: http://www.tecmint.com/check-memory-usage-in-linux/ 作者：[Ravi Saive][a] 译者：[译者ID](https://github.com/译者ID) 校对：[校对者ID](https://github.com/校对者ID) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出 [a]:http://www.tecmint.com/author/admin/