Mac OS X sysctl get total and free memory size

Question

How to get on MAC OS X using sysctl used and free memory ? Searched for sysctl -a | grep vm or sysctl -a | grep mem but didn't found anything relevant.

Solution 1

You don't.

Well, except for total memory size, which you could have found with sysctl -a | grep mem (hw.memsize = 4294967296 on my machine).

vm_stat displays the same information as Activity Monitor.app does, you just need to multiply the value you want by page size. Both are provided in the output.

Solution 2

No grep is needed.

sysctl -n hw.memsize

Solution 3

top -l 1 | grep PhysMem: | awk '{print $10}'

top -l 1 runs top in logging mode (e.g. file output, not display/terminal output) for one iteration, then quits. The grep/awk filters for the free memory value in top output.

Solution 4

mac os x/ linux

$ sysctl -a | grep '^hw\.m'
hw.memsize: 8589934592

Solution 5

Why not use the top command to view your memory usage in realtime?

UPDATE:

You can use the following commands:

sysctl -a | grep hw.usermem
sysctl -a | grep hw.physmem

For a complete listing type man sysctl in terminal.

View more solutions

Comments

[Admin]

Also see Is there a Mac OS X Terminal version of the “free” command in Linux systems? on the Apple Stack Exchange.

[HikeMike]

Probably for use in a script.

[HikeMike]

Both usermem and physmem display useless values for systems over 2GB RAM. Both are probably bounded by a signed 32 bit integer.

[kesrut]

Maybe i can use top to get single output. After i get the output i will parse needed values.

[kesrut]

vm_stat: pages free: 12054 .. 12054 * 4096 / 1024 / 1024 = 47.08 and Activity monitor shows: 103 MB grab.by/6KSD VM_stats output: pastebin.com/BJcxPswv Why i get wrong values ?

[HikeMike]

Add Pages speculative to the free ones. You might have noticed that free+active+inactive+wired down don't add to the total size displayed in Activity Monitor.

[Nallasamy Nss]

@DanielBeck is right, hw.memsize is what you probably want for total. See my comment here for more info

[fixer1234]

This looks like a minor tweak to existing answers. Probably more appropriate as a comment.

[pyb]

YMMV. On Sierra, top -l 1 | grep PhysMem: gives me PhysMem: 9674M used (1752M wired), 6701M unused. so I used top -l 1 | grep PhysMem: | awk '{print $6}'. Thanks!