time.h

问题 I was trying to familiarize myself with the C time.h library by writing something simple in VS. The following code simply prints the value of x added to itself every two seconds: int main() { time_t start = time(NULL); time_t clock = time(NULL); time_t clockTemp = time(NULL); //temporary clock int x = 1; //program will continue for a minute (60 sec) while (clock <= start + 58) { clockTemp = time(NULL); if (clockTemp >= clock + 2) { //if 2 seconds has passed clock = clockTemp; x = ADD(x);

问题 I was trying to familiarize myself with the C time.h library by writing something simple in VS. The following code simply prints the value of x added to itself every two seconds: int main() { time_t start = time(NULL); time_t clock = time(NULL); time_t clockTemp = time(NULL); //temporary clock int x = 1; //program will continue for a minute (60 sec) while (clock <= start + 58) { clockTemp = time(NULL); if (clockTemp >= clock + 2) { //if 2 seconds has passed clock = clockTemp; x = ADD(x);

来源： https://stackoverflow.com/questions/19366943/clock-returning-a-negative-value-in-c

来源： https://stackoverflow.com/questions/19366943/clock-returning-a-negative-value-in-c

来源： https://stackoverflow.com/questions/19366943/clock-returning-a-negative-value-in-c

问题 I have my C program with time function declared globally as follows: time_t t = time(NULL); struct tm *tm = localtime(&t); time(&rawtime); void file_name() { sprintf(buffer,"data/log_%d.%d_%d:%d:%d",tm->tm_mon+1,tm->tm_mday,tm->tm_hour,tm->tm_min,tm->tm_sec); char *p = buffer; for(;*p;++p) { if(*p == ' ') *p = '_'; } printf("%s",buffer); } } void create_file() { file_name(); fptr = fopen(buffer,"w"); } void read_data(); { . . . . sprintf(buffer1,"_%d:%d:%d",tm->tm_hour,tm->tm_min,tm_sec);

问题 The time function in time.h gives milliseconds since the epoch. 回答1: This is a simple way: time_t seconds_since_midnight = time(NULL) % 86400; To get approximate milliseconds since midnight, multiply seconds_since_midnight by 1000. If you need more resolution (consider whether you really do), you will have to use another function such as gettimeofday() . 回答2: This is the precise way: struct timeval tv; int msec = -1; if (gettimeofday(&tv, NULL) == 0) { msec = ((tv.tv_sec % 86400) * 1000 + tv

问题 In a question about getting a system's time zone, this answer did not get up-voted. It suggests the use of tzset() and some system globals (e.g. daylight , timezone , and tzname ) from time.h . After some testing, I was able to get accurate results from this method on both Windows and Mac. But I'm guessing the answer mentioned above was not up-voted for a reason. Is this true? Should I prefer OS-specific calls instead of this C-standard? 回答1: No, if there is not an standard C function (and

问题 I am trying to implement a game using ncurses in C. I have to show the current time (the time must update each second) and my while loop looks like this while(1) { clk = time(NULL); cur_time = localtime(&clk); mvprintw(0,1,"%d %d %d",cur_time->tm_hour,cur_time->tm_min,cur_time->tm_sec); int key = getch() //other stuff } My problem is that the time will refresh only when I press a key. Is it a way to make the time refresh without the need of pressing a key (and to implement this in the same

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: How to measure time in milliseconds using ANSI C? How can I get the Windows system time with millisecond resolution? We want to calculate the time which a player have taken to finish the game. But with time.h we could only calculate in seconds. but that is not exact. Is it possible to get the time in milliseconds? and what is the %? to printf? 回答1: quick answer #include<stdio.h> #include<time.h> int main() {