Retrieve system information on MacOS X? [closed]

问题

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.

Closed 8 years ago.

Using C++ is there anyway I could get basic information about the computer? For example is there a way I could check how much memory is being used (by the whole computer not just my computer), the total memory available, virtual memory usage, CPU usage, networks stats and so on?

I am using Mac OS X Snow Leopard but I would prefer a solution that could be implemented for all Mac OSs (i.e. Lion)

回答1:

For system-wide memory usage information under MacOS/X, open and read the file /usr/bin/vm_stat, something like this:

static double ParseMemValue(const char * b)
{
   while((*b)&&(isdigit(*b) == false)) b++;
   return isdigit(*b) ? atof(b) : -1.0;
}

// Returns a number between 0.0f and 1.0f, with 0.0f meaning all RAM is available, and 1.0f meaning all RAM is currently in use
float GetSystemMemoryUsagePercentage()
{
   FILE * fpIn = popen("/usr/bin/vm_stat", "r");
   if (fpIn)
   {
      double pagesUsed = 0.0, totalPages = 0.0;
      char buf[512];
      while(fgets(buf, sizeof(buf), fpIn) != NULL)
      {
         if (strncmp(buf, "Pages", 5) == 0)
         {
            double val = ParseMemValue(buf);
            if (val >= 0.0)
            {
               if ((strncmp(buf, "Pages wired", 11) == 0)||(strncmp(buf, "Pages active", 12) == 0)) pagesUsed += val;
               totalPages += val;
            }
         }
         else if (strncmp(buf, "Mach Virtual Memory Statistics", 30) != 0) break;  // Stop at "Translation Faults", we don't care about anything at or below that
      }
      pclose(fpIn);

      if (totalPages > 0.0) return (float) (pagesUsed/totalPages);
   }
   return -1.0f;  // indicate failure
}

For a CPU usage indicator, do something like this:

#include <mach/mach_init.h>
#include <mach/mach_error.h>
#include <mach/mach_host.h>
#include <mach/vm_map.h>

static unsigned long long _previousTotalTicks = 0;
static unsigned long long _previousIdleTicks = 0;

// Returns 1.0f for "CPU fully pinned", 0.0f for "CPU idle", or somewhere in between
// You'll need to call this at regular intervals, since it measures the load between
// the previous call and the current one.
float GetCPULoad()
{
   host_cpu_load_info_data_t cpuinfo;
   mach_msg_type_number_t count = HOST_CPU_LOAD_INFO_COUNT;
   if (host_statistics(mach_host_self(), HOST_CPU_LOAD_INFO, (host_info_t)&cpuinfo, &count) == KERN_SUCCESS)
   {
      unsigned long long totalTicks = 0;
      for(int i=0; i<CPU_STATE_MAX; i++) totalTicks += cpuinfo.cpu_ticks[i];
      return CalculateCPULoad(cpuinfo.cpu_ticks[CPU_STATE_IDLE], totalTicks);
   }
   else return -1.0f;
}

float CalculateCPULoad(unsigned long long idleTicks, unsigned long long totalTicks)
{
  unsigned long long totalTicksSinceLastTime = totalTicks-_previousTotalTicks;
  unsigned long long idleTicksSinceLastTime  = idleTicks-_previousIdleTicks;
  float ret = 1.0f-((totalTicksSinceLastTime > 0) ? ((float)idleTicksSinceLastTime)/totalTicksSinceLastTime : 0);
  _previousTotalTicks = totalTicks;
  _previousIdleTicks  = idleTicks;
  return ret;
}

For network statistics, I don't know the solution (other than maybe to run netstat and parse the results somehow... it depends on what network statistics you are interested in I suppose).

回答2:

First off if you are focusing on Mac OS only, then the language of choice should be Objective - C.

Steps you need to follow

1. Learn Obj-C, not really that hard, i come from a c++ background myself and after a few weeks of working on the platform with this language i became rather fluent
2. Check the Mac OSX developer Library : Mac OS X Developer Library
3. Check out this
4. And this

来源：https://stackoverflow.com/questions/8736713/retrieve-system-information-on-macos-x