ctime, localtime, gmtime, asctime, tm2sec, timezone – convert date
char* ctime(long clock)
Tm* localtime(long clock)
Tm* gmtime(long clock)
char* asctime(Tm *tm)
long tm2sec(Tm *tm)
Ctime converts a time clock such as returned by time(3) into ASCII
(sic) and returns a pointer to a 30-byte string in the following
form. All the fields have constant width.
Localtime and gmtime return pointers to structures containing
the broken-down time. Localtime corrects for the time zone and
possible daylight savings time; gmtime converts directly to GMT.
Asctime converts a broken-down time to ASCII and returns a pointer
to a 30-byte string.
Wed Aug 5 01:07:47 EST 1973\n\0
Tm2sec converts a broken-down time to seconds since the start
of the epoch. It ignores wday, and assumes the local time zone
if zone is not GMT.
int sec; /* seconds (range 0..59) */|
int min; /* minutes (0..59) */
int hour; /* hours (0..23) */
int mday; /* day of the month (1..31) */
int mon; /* month of the year (0..11) */
int year; /* year A.D. – 1900 */
int wday; /* day of week (0..6, Sunday = 0) */
int yday; /* day of year (0..365) */
char zone; /* time zone name */
int tzoff; /* time zone delta from GMT */
The return values point to static data whose content is overwritten
by each call.
Daylight Savings Time is “normal” in the Southern hemisphere.
These routines are not equipped to handle non-ASCII text, and
are provincial anyway.
To avoid name conflicts with the underlying system, ctime, localtime,
gmtime, asctime, and tm2sec are preprocessor macros defined as
p9ctime, p9localtime, p9gmtime, p9asctime, and p9tm2sec; see intro(3).|