#include <stdio.h>#include <time.h>#include <string.h> static char *weekday[] = { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" };static char *wday[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };static char *month[] = { "January", "February", "March", "April", "May", "June", "July", "August", "September",	"October", "November", "December" };static char *mon[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };  size_t strftime(char  *buf, size_t maxsize, const char *fmt, const struct tm *tm){	char *ep = buf + maxsize - 1;	char *p = buf;	int c;	char tmp[40];		while (*fmt) {		if ((c = *fmt++) != '%') {			if (p >= ep)				return 0;			*p++ = c;			continue;		}				switch (c = *fmt++) {		case 0:			return 0;				default:			if (p+1 >= ep)				return 0;			*p++ = '%';			*p++ = c;			break;				case 'A':			strcpy(tmp, weekday[tm->tm_wday]);			break;		case 'a':			strcpy(tmp, wday[tm->tm_wday]);			break;		case 'B':			strcpy(tmp, month[tm->tm_mon]);			break;		case 'h':		case 'b':			strcpy(tmp, mon[tm->tm_mon]);			break;		case 'C':			sprintf(tmp, "%02d", (tm->tm_year+1900)/100);			break;		case 'c':			sprintf(tmp, "%02d:%02d:%02d %02d/%02d/%04d",				tm->tm_hour, tm->tm_min, tm->tm_sec,				tm->tm_mon+1, tm->tm_mday, tm->tm_year+1900);			break;		case 'D':			strftime(tmp, sizeof tmp, "%m/%d/%y", tm);			break;		case 'd':			sprintf(tmp, "%02d", tm->tm_mday);			break;		case 'e':			sprintf(tmp, "%2d", tm->tm_mday);			break;		case 'F':			strftime(tmp, sizeof tmp, "%Y-%m-%d", tm);			break;		case 'G':			// Not quite right - sometimes the previous or next year!			sprintf(tmp, "%04d", tm->tm_year + 1900);			break;		case 'g':			strftime(tmp, sizeof tmp, "%G", tm);			memmove(tmp, tmp+2, strlen(tmp+2)+1);			break;		case 'H':			sprintf(tmp, "%02d", tm->tm_hour);			break;		case 'I':			sprintf(tmp, "%02d", (tm->tm_hour+11) % 12 + 1);			break;		case 'j':			sprintf(tmp, "%03d", tm->tm_yday + 1);			break;		case 'k':			sprintf(tmp, "%2d", tm->tm_hour);			break;		case 'l':			sprintf(tmp, "%2d", (tm->tm_hour+11) % 12 + 1);			break;		case 'M':			sprintf(tmp, "%02d", tm->tm_min);			break;		case 'm':			sprintf(tmp, "%02d", tm->tm_mon+1);			break;		case 'n':			strcpy(tmp, "\n");			break;		case 'p':			if (tm->tm_hour < 12)				strcpy(tmp, "am");			else				strcpy(tmp, "pm");			break;		case 'R':			strftime(tmp, sizeof tmp, "%H:%M", tm);			break;		case 'r':			strftime(tmp, sizeof tmp, "%I:%M:%S %p", tm);			break;		case 'S':			sprintf(tmp, "%02d", tm->tm_sec);			break;		case 's':			sprintf(tmp, "%d", (int)mktime(tm));			break;		case 'T':			strftime(tmp, sizeof tmp, "%H:%M:%S", tm);			break;		case 't':			strcpy(tmp, "\t");			break;		case 'U':			sprintf(tmp, "%02d", tm->tm_yday/7);  // not quite right			break;		case 'u':			sprintf(tmp, "%d", tm->tm_wday ? tm->tm_wday : 7);			break;		case 'V':			sprintf(tmp, "%02d", 1 + tm->tm_yday/7);  // not quite right			break;		case 'v':			strftime(tmp, sizeof tmp, "%e-%b-%Y", tm);			break;		case 'W':			sprintf(tmp, "%02d", tm->tm_yday/7);  // not quite right			break;		case 'w':			sprintf(tmp, "%d", tm->tm_wday);			break;		case 'X':			sprintf(tmp, "%02d:%02d:%02d",				tm->tm_hour, tm->tm_min, tm->tm_sec);			break;		case 'x':			sprintf(tmp, "%%02d/%02d/%04d",				tm->tm_mon+1, tm->tm_mday, tm->tm_year+1900);			break;		case 'Y':			sprintf(tmp, "%d", tm->tm_year+1900);			break;		case 'y':			sprintf(tmp, "%02d", tm->tm_year%100);			break;		case 'Z':			strcpy(tmp, "GMT");			break;		case 'z':			strcpy(tmp, "+0000");			break;		case '%':			strcpy(tmp, "%");			break;		}		if(p+strlen(tmp) > ep)			return 0;		strcpy(p, tmp);		p += strlen(p);	}	*p = 0;	return p - buf;}