C language timer sample sharing

Developed under Linux, using the C language. For software development that requires timing, it sends out SIGALRM signals in real system time. At regular intervals of one second

C language timer

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "pthread.h"
#include <netinet/in.h>
#include <signal.h>
#include <sys/time.h>

struct StructOfTimerStatus
{
    unsigned int count;                               //count
    unsigned int flag;                                //Timing mark
}
;
struct StructOfTimer
{  
    struct StructOfTimerStatus      testtime;   //Test timer
}
mytime;
 
void SetTimer(int sec,int usec);
void SigalrmFunc(void);

//Timer function

void SigalrmFunc(void)
{
    if(mytime.testtime.count++>20)      //20 times 50,000 is 1s
    {
        mytime.testtime.flag=1;
        mytime.testtime.count=0;
    }
}

void SetTimer(int sec,int usec)
{
    struct itimerval value,ovalue;
    signal(SIGALRM,(void *)SigalrmFunc);

    value.it_value.tv_sec = sec;
    value.it_value.tv_usec = usec;
    value.it_interval.tv_sec = sec;
    value.it_interval.tv_usec = usec;

    setitimer(ITIMER_REAL,&value,&ovalue); 
}
int main(int argc, char **argv)
{
    SetTimer(0, 50000);
    while(1)
    {
        if(mytime.testtime.flag == 1)
        {
            mytime.testtime.flag = 0;
            system("clear");
            printf("Timing successn"); 
        }
    }
    return 0;
}