host wide cpu usage on a mac

hostwide.c

#include <stdio.h>
#include <mach/mach.h>
#include <mach/mach_host.h>

int main() {
    // Get the host's CPU statistics
    host_cpu_load_info_data_t cpu_info;
    mach_msg_type_number_t count = HOST_CPU_LOAD_INFO_COUNT;
    kern_return_t kr = host_statistics(mach_host_self(), HOST_CPU_LOAD_INFO, (host_info_t)&cpu_info, &count);
    
    if (kr != KERN_SUCCESS) {
        fprintf(stderr, "host_statistics failed: %s\n", mach_error_string(kr));
        return 1;
    }

    // Calculate the total CPU usage
    unsigned long long total = cpu_info.cpu_ticks[CPU_STATE_USER] +
                               cpu_info.cpu_ticks[CPU_STATE_SYSTEM] +
                               cpu_info.cpu_ticks[CPU_STATE_IDLE] +
                               cpu_info.cpu_ticks[CPU_STATE_NICE];

    unsigned long long total_used = cpu_info.cpu_ticks[CPU_STATE_USER] +
                                     cpu_info.cpu_ticks[CPU_STATE_SYSTEM] +
                                     cpu_info.cpu_ticks[CPU_STATE_NICE];

    double cpu_usage = (double)total_used / total * 100.0;
    printf("CPU Usage: %.2f%%\n", cpu_usage);

    return 0;
}