/* *
#include <sys/time.h>
int setitimer(int which, const struct itimerval *value, struct itimerval *ovalue);
struct itimerval
{
struct timerval it_interval;
struct timerval it_value;
}
struct timeval
{
long tv_sec;
long tv_usec;
}
*/
#include <stdio.h> // for printf()
#include <unistd.h> // for pause()
#include <signal.h> // for signal()
#include <string.h> // for memset()
#include <sys/time.h> // struct itimeral,setitimer()
#include <time.h> // for localtime(),asctime(),time()
void printMsg(int);
int main()
{
// Get system call result to determine successful or failed
int res = 0;
// Register printMsg to SIGALRM
signal(SIGALRM, printMsg);
struct itimerval tick;
// Initialize struct
memset(&tick, 0, sizeof(tick));
// Timeout to run function first time
tick.it_value.tv_sec = 1; // sec
tick.it_value.tv_usec = 0; // micro sec.
// Interval time to run function
tick.it_interval.tv_sec = 1;
tick.it_interval.tv_usec = 0;
// Set timer, ITIMER_REAL : real-time to decrease timer,
// send SIGALRM when timeout
res = setitimer(ITIMER_REAL, &tick, NULL);
if (res)
{
printf("Set timer failed!!/n");
}
// Always sleep to catch SIGALRM signal
while(1)
{
pause();
}
return 0;
}
void printMsg(int num)
{
time_t now;
time(&now);
printf("Hello World!! %s ", asctime(localtime(&now)));
}
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