Determine physical mem size programmatically on OSX

Question

We\'re trying to find out how much physical memory is installed in a machine running Mac OS X. We\'ve found the BSD function sysctl(). The problem is this function wants to

Answer 1

From Obtaining a Mac’s System Profiler data from shell:

Use system_profiler.

Answer 2

Did you try googling?

This seems to be the answer: http://lists.apple.com/archives/scitech/2005/Aug/msg00004.html

sysctl() does work, you just need to fetch hw.memsize instead of hw.physmem. hw.memsize will give you a uint64_t, so no 32 bit problem.

Answer 3

Alternatively you can add the data from vm_statistics_data_t to get the total memory

vm_statistics_data_t vm_stat;
int count = HOST_VM_INFO_COUNT;
kern_return_t kernReturn = host_statistics(mach_host_self(), HOST_VM_INFO, (integer_t*)&vm_stat, (mach_msg_type_number_t*)&count);

Answer 4

The answer is to use sysctl to get hw.memsize as was suggested in a previous answer. Here's the actual code for doing that.

#include <sys/types.h>
#include <sys/sysctl.h>

...

    int mib[2];
    int64_t physical_memory;
    size_t length;

    // Get the Physical memory size
    mib[0] = CTL_HW;
    mib[1] = HW_MEMSIZE;
    length = sizeof(int64_t);
    sysctl(mib, 2, &physical_memory, &length, NULL, 0);