myon

get_current_time_as_YYYYmmdd.c

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

#define         TIME_PREFIX_SIZE  8 // "YYYYmmdd"

int main() 
{
    struct tm *current_tm;
    time_t current_time;
    char buf[TIME_PREFIX_SIZE] = {};

    current_time = time(NULL);
    current_tm = localtime(&current_time);

    assert(TIME_PREFIX_SIZE == strftime(buf, TIME_PREFIX_SIZE + 1 /* contains null byte */, "%Y%m%d", current_tm));

    printf("%d - ", strlen(buf));
    puts(buf);

    return 0;
}