NetBSD/dist/ntp/libntp/prettydate.c

135 lines
3.0 KiB
C

/* $NetBSD: prettydate.c,v 1.3 2006/06/11 19:34:10 kardel Exp $ */
/*
* prettydate - convert a time stamp to something readable
*/
#include <stdio.h>
#include "ntp_fp.h"
#include "ntp_unixtime.h" /* includes <sys/time.h> */
#include "lib_strbuf.h"
#include "ntp_stdlib.h"
static const char *months[] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
static const char *days[] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
/* Helper function to handle possible wraparound of the ntp epoch.
Works by assuming that the localtime/gmtime library functions
have been updated so that they work
*/
#define MAX_EPOCH_NR 1000
struct tm *
ntp2unix_tm(
u_long ntp, int local
)
{
time_t t, curr;
struct tm *tm;
int curr_year, epoch_nr;
/* First get the current year: */
curr = time(NULL);
tm = local ? localtime(&curr) : gmtime(&curr);
if (!tm) return NULL;
curr_year = 1900 + tm->tm_year;
/* Convert the ntp timestamp to a unix utc seconds count: */
t = (time_t) ntp - JAN_1970;
/* Check that the ntp timestamp is not before a 136 year window centered
around the current year:
Failsafe in case of an infinite loop:
Allow up to 1000 epochs of 136 years each!
*/
for (epoch_nr = 0; epoch_nr < MAX_EPOCH_NR; epoch_nr++) {
tm = local ? localtime(&t) : gmtime(&t);
#if SIZEOF_TIME_T < 4
# include "Bletch: sizeof(time_t) < 4!"
#endif
#if SIZEOF_TIME_T == 4
/* If 32 bits, then year is 1970-2038, so no sense looking */
epoch_nr = MAX_EPOCH_NR;
#else /* SIZEOF_TIME_T > 4 */
/* Check that the resulting year is in the correct epoch: */
if (1900 + tm->tm_year > curr_year - 68) break;
/* Epoch wraparound: Add 2^32 seconds! */
t += (time_t) 65536 << 16;
#endif /* SIZEOF_TIME_T > 4 */
}
return tm;
}
char *
prettydate(
l_fp *ts
)
{
char *bp;
struct tm *tm;
time_t sec;
u_long msec;
LIB_GETBUF(bp);
sec = ts->l_ui;
msec = ts->l_uf / 4294967; /* fract / (2 ** 32 / 1000) */
tm = ntp2unix_tm(sec, 1);
if (!tm) {
(void) sprintf(bp, "%08lx.%08lx --- --- -- ---- --:--:--",
(u_long)ts->l_ui, (u_long)ts->l_uf);
}
else {
(void) sprintf(bp, "%08lx.%08lx %s, %s %2d %4d %2d:%02d:%02d.%03lu",
(u_long)ts->l_ui, (u_long)ts->l_uf, days[tm->tm_wday],
months[tm->tm_mon], tm->tm_mday, 1900 + tm->tm_year,
tm->tm_hour,tm->tm_min, tm->tm_sec, msec);
}
return bp;
}
char *
gmprettydate(
l_fp *ts
)
{
char *bp;
struct tm *tm;
time_t sec;
u_long msec;
LIB_GETBUF(bp);
sec = ts->l_ui;
msec = ts->l_uf / 4294967; /* fract / (2 ** 32 / 1000) */
tm = ntp2unix_tm(sec, 0);
if (!tm) {
(void) sprintf(bp, "%08lx.%08lx --- --- -- ---- --:--:--",
(u_long)ts->l_ui, (u_long)ts->l_uf);
}
else {
(void) sprintf(bp, "%08lx.%08lx %s, %s %2d %4d %2d:%02d:%02d.%03lu",
(u_long)ts->l_ui, (u_long)ts->l_uf, days[tm->tm_wday],
months[tm->tm_mon], tm->tm_mday, 1900 + tm->tm_year,
tm->tm_hour,tm->tm_min, tm->tm_sec, msec);
}
return bp;
}