#include <stdio.h>

#include <unistd.h>

long get_memory_usage()

{

    long page_size = sysconf (_SC_PAGESIZE);

    long num_pages = sysconf (_SC_PHYS_PAGES);

    long mem = (num_pages/) * (page_size/);

    long long free_pages = sysconf (_SC_AVPHYS_PAGES);

    long long free_mem = (free_pages/) * (page_size/);

    fprintf(stderr,"Memory %lld MB\\%lld MB.\n", mem, free_mem);

    return (long)(free_mem);

}

#include <stdio.h>

#include <unistd.h>

#include <stdlib.h>

#include <string.h>

long get_memory_usage()

{

    FILE*file=fopen("/proc/meminfo","r");

    if(file == NULL){

        fprintf(stderr,"cannot open /proc/meminfo\n");

        return -1;

    }

    char keyword[];

    char valuech[];

    long mem        =;

    long free_mem   =;

    fscanf(file,"MemTotal: %s kB\n",keyword);

    mem=atol(keyword)/;

    fscanf(file,"MemFree: %s kB\n",valuech);

    fscanf(file,"MemAvailable: %s kB\n",valuech);

    free_mem=atol(valuech)/;

    fclose(file);

    fprintf(stderr,"Memory %ld MB\\%ld MB.\n", mem, free_mem);

    return (long)(free_mem);

}