How to write a c++ program using linux system call which gives output about free memory, used memory, kernel version?

Question

On a Linux system, using a C++ program, I need to find a way to print out the following information:

Amount of memory in use.
Amount of Free memory
Linux Kernel Version.

Can anyone help me on how to achieve this?

Thank you.

could this be of help ? http://stackoverflow.com/questions/13883606/how-to-find-out-the-amount-of-free-physical-memory-under-linux-in-c — mlwn, Nov 11 '14 at 15:18
This is a very confusing and unclear question. What is the memory you are talking about? "amount of free memory" is *very* ambiguous. — Basile Starynkevitch, Nov 11 '14 at 15:45

score 3 · Answer 1 · edited May 23 '17 at 12:12

You could use the proc(5) file system (it is specific to Linux). You might read sequentially /proc/meminfo and /proc/version (these pseudo-files should be read sequentially, and they are quick, not involving any disk IO). You could also use uname(2) for the version of the kernel.

If you want to query about virtual memory for your own process, use /proc/self/maps

If you need information related to malloc(3), use malloc_info(3), mallinfo(3), malloc_stats(3), ...

The comment by mlwn also mentions rightly sysconf(3)

See also linuxatemyram. And read Advanced Linux Programming

It is possible to limit the used (or available) memory, see this answer. Use getrlimit(2) to query the resource limits.

^{PS. Your mention of amount of memory in use is very ambiguous! Notice also that syscalls(2) are not the same as system(3)}

How to write a c++ program using linux system call which gives output about free memory, used memory, kernel version?

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