windows:

void defP(){
	    // Task Manager windows 10 uses VM_COUNTERS_EX2 similar structure is defined (in ntddk.h)
		MEMORYSTATUSEX memInfo;
		memInfo.dwLength = sizeof(MEMORYSTATUSEX);
		GlobalMemoryStatusEx(&memInfo);
		DWORDLONG totalVirtualMem = memInfo.ullTotalPageFile;
		
		DWORDLONG virtualMemUsed = memInfo.ullTotalPageFile - memInfo.ullAvailPageFile;
		
		PROCESS_MEMORY_COUNTERS_EX pmc;
		GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*)&pmc, sizeof(pmc));
		SIZE_T virtualMemUsedByMe = pmc.PrivateUsage;
		
		DWORDLONG totalPhysMem = memInfo.ullTotalPhys;
		
		DWORDLONG physMemUsed = memInfo.ullTotalPhys - memInfo.ullAvailPhys;
		
		SIZE_T physMemUsedByMe = pmc.WorkingSetSize;
		
		SIZE_T  x=pmc.PagefileUsage;
		SIZE_T y=pmc.PrivateUsage;
		Cout() <<"m virtual usada-----> " << virtualMemUsedByMe/1024 << EOL;
		Cout() <<"m fisica usada-----> " << physMemUsed/1024/1024 << EOL;
		Cout() <<"total m  usada-----> " << totalPhysMem << EOL;
		Cout() <<"m privada usada-----> " << y/1024 << EOL;
			
}
 
CONSOLE_APP_MAIN
{
  SetLanguage("pt-br");
  SetDateFormat("%3:02d/%2:02d/%1:4d"); // format code in editor
  SetDateScan("dmy");
  
  defP();
  
}
 
linux:
#include <iostream>
#include <Core/Core.h>
#include <SysInfo/SysInfo.h>
 
using namespace Upp;
 
int parseLine(char* line){
    // This assumes that a digit will be found and the line ends in " Kb".
    int i = strlen(line);
    const char* p = line;
    while (*p <'0' || *p > '9') p++;
    line[i-3] = '\0';
    i = atoi(p);
    return i;
}
 
int getValue(){ //Note: this value is in KB!
    FILE* file = fopen("/proc/self/status", "r");
    int result = -1;
    char line[128];
 
    while (fgets(line, 128, file) != NULL){
        if (strncmp(line, "VmRSS:", 6) == 0){
            result = parseLine(line);
            break;
        }
    }
    fclose(file);
    return result;
}
 
CONSOLE_APP_MAIN 
{
	Cout() << "--> " << getValue() << EOL;
}