AT&T UNIX™PC Unix System V Users Manual - tenox

CTIME ( 3C ) CTIME ( 3C )
NAME
ctime, localtime, gmtime, asctime, tzset - convert date and time
to string
SYNOPSIS
#include
char •ctime {clock)
long •clock;
struct tm •Iocaltime {clock)
long •clock;
struct tm •gmtime (clock)
long •clock;
char •asctime (tm)
struct tm •tm;
extern long timezone;
extern int daylight;
extern char •tzname[2];
void tzset ( )
DESCRIPTION
Ctime converts a long integer, pointed to by clock, representing
the time in seconds since 00:00:00 GMT, January 1, 1970, and
returns a pointer to a 26-character string in the following form.
All the fields have constant width.
Sun Sep 16 01:03:52 1973\n\0
Localtime and gmtime return pointers to "tm" structures,
described below. Localtime corrects for the time zone and possible
Daylight Savings Time; gmtime converts directly to
Greenwich Mean Time (GMT), which is the time the UNIX system
uses.
Asctime converts a "tm" structure to a 26-character string, as
shown in the above example, and returns a pointer to the string.
Declarations of all the functions and externals, and the "tm"
structure, are in the header file. The structure
declaration is:
struct tm {
int tm_sec; I* seconds (0 - 59) *I
int tm_min; I* minutes (0 - 59) *I
int tm_hour; I* hours (0 -23) *I
int tm_mday; I* day of month (1 - 31) *I
int tm_mon; I* month of year (0 - 11) *I
int tm_year; I* year - 1900 *I
int tm_wday; I* day of week (Sunday = 0) *I
int tm_yday; I* day of year (0 - 365) *I
int tm_isdst;
};
Tm_isdst is non-zero if Daylight Savings Time is in effect.
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