Thread: This program makes my computer SLOW

This program is an alarm clock you enter a date and time and it will tell you when its that time. The only problem is that it keeps having to get the time which makes it impossible to run any other big programs (which I won't to do) So can someone please help me make it more PC friendly

Code:

#include<time.h>
#include<stdio.h>

int main(void)
{
char hello[100], user[100];
int f;
  time_t timer;
  timer=time(NULL);
  strcpy(hello,asctime(localtime(&timer)));
  timer=time(NULL);
  printf("%s", &hello);
  fgets(user, 100, stdin);
  printf("%s", user);
  
  
  while (f!=3)
  {
  strcpy(hello,asctime(localtime(&timer)));
  if (strncasecmp(hello, user, 100) == 0)
  {
  printf("\n\n\t\t\tYES");
  f=3;
  }
  timer=time(NULL);
  }
  
  return 0;
}

Also how do I check to see if the time and date has already pasted.

I tryed but it doesn't work heres my code...

Code:

#include<windows.h>
#include<time.h>
#include<stdio.h>

int main(void)
{
char hello[100], user[100];
int f, elapsed;
  time_t timer;
  timer=time(NULL);
  strcpy(hello,asctime(localtime(&timer)));
  timer=time(NULL);
  
  printf("%s", &hello);
  fgets(user, 100, stdin);
  printf("The timer is primed and shall alert you when your entered time has been reached\nDO NOT EXIT otherwise timer shall stop(run in the background)\n");
  

  while (f!=3)
  {
  strcpy(hello,asctime(localtime(&timer)));
  
  if (strncasecmp(hello, user, 100) == 0)
  {
  MessageBox(NULL, "BEEP BEEP!", "BEEP!", MB_OK);
  f=3;
  }
  elapsed = difftime(hello, user);
  if (elapsed < 0)
  {
  printf("Yes");
  f=3;
  }
  timer=time(NULL);
  sleep (100);
  }
  MessageBox(NULL, "Thank you for using DG's alarm clock I hope it was usful\n\thttp://members.aol.com/dg1234uk", "DG's Alarm Clock!", MB_OK);
  return 0;
}

Well how do I put the users input into a time(and not a string)? So I can use difftime?

(My compiler didn't come up with any errors!)

Here's my stab

Code:

#include <stdio.h>
#include <time.h>
#include <unistd.h>     // sleep()

void wait_for_alarm ( time_t alarm ) {
    time_t  now = time(NULL);
    while ( difftime(alarm,now) > 0 ) {
        sleep( 1 );
        now = time(NULL);
    }
    printf( "Alarm!!!\n" );
}

int main ( ) {
    time_t      now, alarm;
    char        buff[BUFSIZ];
    struct tm   tm = { 0 };

    printf( "Enter time in yyyy/mm/dd hh:mm:ss format > " );
    fflush( stdout );
    if ( fgets( buff, BUFSIZ, stdin ) != NULL ) {
        int yr, mon, day, hr, min, sec;
        if ( sscanf( buff, "%d/%d/%d %d:%d:%d",
                     &yr, &mon, &day, &hr, &min, &sec ) == 6 ) {
            tm.tm_sec = sec;
            tm.tm_min = min;
            tm.tm_hour= hr;
            tm.tm_mday= day;
            tm.tm_mon = mon-1;
            tm.tm_year= yr-1900;
            alarm = mktime( &tm );
            now = time( NULL );
            if ( difftime(alarm,now) < 0 ) {
                printf( "Alarm time passed\n" );
            } else {
                wait_for_alarm( alarm );
            }
        }
    }
    return 0;
}