How to print time in format: 2009‐08‐10 18:17:54.811

Question

What\'s the best method to print out time in C in the format 2009‐08‐10 
18:17:54.811?

Answer 1

Following code prints with microsecond precision. All we have to do is use gettimeofday and strftime on tv_sec and append tv_usec to the constructed string.

#include 
#include 
#include 
int main(void) {
    struct timeval tmnow;
    struct tm *tm;
    char buf[30], usec_buf[6];
    gettimeofday(&tmnow, NULL);
    tm = localtime(&tmnow.tv_sec);
    strftime(buf,30,"%Y:%m:%dT%H:%M:%S", tm);
    strcat(buf,".");
    sprintf(usec_buf,"%dZ",(int)tmnow.tv_usec);
    strcat(buf,usec_buf);
    printf("%s",buf);
    return 0;
}