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May 19, 2015 - A Look At The New Commandlinefu
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Print number of mb of free ram

Terminal - Print number of mb of free ram
free -m | awk '/buffer/ {print $4}'
2010-06-27 23:30:27
User: DaveQB
Functions: awk free
Print number of mb of free ram

Here we instead show a more real figure for how much free RAM you have when taking into consideration buffers that can be freed if needed.

Unix machines leave data in memory but marked it free to overwrite, so using the first line from the "free" command will mostly give you back a reading showing you are almost out of memory, but in fact you are not, as the system can free up memory as soon as it is needed.

I just noticed the free command is not on my OpenBSD box.


There are 7 alternatives - vote for the best!

Terminal - Alternatives
grep '^MemFree:' /proc/meminfo | awk '{ mem=($2)/(1024) ; printf "%0.0f MB\n", mem }'
2010-06-30 18:33:29
User: dbbolton
Functions: awk grep printf

This will show the amount of physical RAM that is left unused by the system.

free -m | awk '/Mem/ {print $4}'

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What others think

The free manpage says :

If the -o option is not specified, free subtracts buffer memory from the used memory and adds it to the free memory reported.

Unix software on unix machines are often made by smart people. Just read the man page.

Comment by CodSpirit 408 weeks and 3 days ago

CodSpirit, I like your thinking, but not having the desired effect here on a CentOS 5.3 box:

[email protected] ~ $ free -m total used free shared buffers cached Mem: 8004 5660 2343 0 68 1639 -/+ buffers/cache: 3953 4050 Swap: 996 0 995 [email protected] ~ $ free -mo total used free shared buffers cached Mem: 8004 5647 2356 0 68 1639 Swap: 996 0 995

3953 is the figure we are after. Omitting the -o switch gives us that.

Comment by DaveQB 389 weeks ago

Rather 4050 for RAM free. 3953 is RAM used.

Comment by DaveQB 389 weeks ago

Your point of view

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