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#include <sys/param.h>
#include <sys/time.h>
#include <sys/file.h>
#include <nlist.h>
#include <stdio.h>
/*
* We declare an array of nlist structures,
* and initialize them to the names of the
* variables we want. The last entry is
* to terminate the list.
*/
struct nlist nl[] = {
#define X_BOOTTIME 0
{ "_boottime" },
#define X_AVENRUN 1
{ "_avenrun" },
{ 0 }
};
main()
{
int kmem;
char *ctime();
struct timeval boottime;
/*
* _avenrun is an array of three numbers.
* Most machines use floating point; Sun
* workstations use long integers.
*/
#ifdef sun
long avenrun[3];
#else
double avenrun[3];
#endif
/*
* Open kernel memory.
*/
if ((kmem = open("/dev/kmem", O_RDONLY)) < 0) {
perror("/dev/kmem");
exit(1);
}
/*
* Read the kernel namelist. If nl[0].n_type is
* 0 after this, then the call to nlist() failed.
*/
if ((nlist("/vmunix", nl) < 0) || (nl[0].n_type == 0)) {
fprintf(stderr, "/vmunix: no namelist\n");
exit(1);
}
/*
* Read the _boottime variable. We do this by
* seeking through memory to the address found
* by nlist, and then reading.
*/
lseek(kmem, (long) nl[X_BOOTTIME].n_value, L_SET);
read(kmem, (char *) &boottime, sizeof(boottime));
/*
* Read the load averages.
*/
lseek(kmem, (long) nl[X_AVENRUN].n_value, L_SET);
read(kmem, (char *) avenrun, sizeof(avenrun));
/*
* Now print the system boot time.
*/
printf("System booted at %s\n", ctime(&boottime.tv_sec));
/*
* Print the load averages. Sun workstations use
* FSCALE to convert the long integers to floating
* point. The three elements of _avenrun are the
* load average over the past one, five, and ten
* minutes.
*/
#ifdef sun
printf("One minute load average: %.2f\n",
(double) avenrun[0] / FSCALE);
printf("Five minute load average: %.2f\n",
(double) avenrun[1] / FSCALE);
printf("Ten minute load average: %.2f\n",
(double) avenrun[2] / FSCALE);
#else
printf("One minute load average: %.2f\n", avenrun[0]);
printf("Five minute load average: %.2f\n", avenrun[1]);
printf("Ten minute load average: %.2f\n", avenrun[2]);
#endif
close(kmem);
exit(0);
}
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