getloadavg - get system load averages

#include <stdlib.h>
int getloadavg(double loadavg[], int n);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

getloadavg():

    Since glibc 2.19:
        _DEFAULT_SOURCE
    In glibc up to and including 2.19:
        _BSD_SOURCE

The getloadavg() function returns the number of processes in the system run queue averaged over various periods of time. Up to n samples are retrieved and assigned to successive elements of loadavg[]. The system imposes a maximum of 3 samples, representing averages over the last 1, 5, and 15 minutes, respectively.

If the load average was unobtainable, -1 is returned; otherwise, the number of samples actually retrieved is returned.

uptime(1), proc(5)