Print a unixtime

format-unixtime.c

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

int main() {
    double time;
    struct tm *gm_t;
    size_t size;
    char s[128];

    time = 1366303735.958;
    int unixtime = (int)floor(time);

    // http://stackoverflow.com/questions/5589383
    // Extract fractional part of double *efficiently* in C
    double fraction = time - ((long)time); // or int64_t

    gm_t = gmtime((time_t *)&unixtime);
    size = strftime(s, sizeof(s), "%a, %d %b %Y %T.%%s %z\n", gm_t);
    char *fr[8];
    s[size] = 0;
    sprintf(fr, "%f", fraction);
    // printf("%s", (char *)&fr + 2);
    printf(s, (char *)&fr + 2);
    return 0;
}