EXAMPLE
#include <linux/unistd.h>
#include <linux/types.h>
#include <linux/sysctl.h>
_syscall1(int, _sysctl, struct __sysctl_args *, args);
int sysctl(int *name, int nlen, void *oldval, size_t *oldlenp,
void *newval, size_t newlen)
{
struct __sysctl_args args={name,nlen,oldval,oldlenp,newval,newlen};
return _sysctl(&args);
}
#define SIZE(x) sizeof(x)/sizeof(x[0])
#define OSNAMESZ 100
char osname[OSNAMESZ];
int osnamelth;
int name[] = { CTL_KERN, KERN_OSTYPE };
main(){
osnamelth = sizeof(osname);
if (sysctl(name, SIZE(name), osname, &osnamelth, 0, 0))
perror("sysctl");
else
printf("This machine is running %*s\n", osnamelth, osname);
return 0;
}
"RETURN VALUE"
Upon successful completion, _sysctl returns 0. Otherwise, a value of -1 is returned and errno is set to indicate the error.
ERRORS