diff options
Diffstat (limited to 'lib/libc/time')
| -rw-r--r-- | lib/libc/time/ctime.3 | 71 |
1 files changed, 36 insertions, 35 deletions
diff --git a/lib/libc/time/ctime.3 b/lib/libc/time/ctime.3 index a5060759717..52c18d96d94 100644 --- a/lib/libc/time/ctime.3 +++ b/lib/libc/time/ctime.3 @@ -1,4 +1,4 @@ -.\" $OpenBSD: ctime.3,v 1.16 1999/11/15 07:45:57 deraadt Exp $ +.\" $OpenBSD: ctime.3,v 1.17 2000/03/06 21:47:27 aaron Exp $ .\" .\" .Dd February 16, 1999 @@ -7,7 +7,7 @@ .Sh NAME .Nm asctime , .Nm ctime , -.N difftime , +.Nm difftime , .Nm gmtime , .Nm localtime , .Nm mktime @@ -31,11 +31,12 @@ .Ft time_t .Fn mktime "struct tm *tm" .Sh DESCRIPTION +The .Fn ctime -converts a -.Ft time_t , +function converts a +.Li time_t , pointed to by -.Ft clock , +.Fa clock , representing the time in seconds since 00:00:00 UTC, 1970-01-01, and returns a pointer to a @@ -47,24 +48,25 @@ Thu Nov 24 18:22:48 1986\en\0 .Pp All the fields have constant width. .Pp +The .Fn localtime and .Fn gmtime -return pointers to -.Ft tm +functions return pointers to +.Li tm structures, described below. .Fn localtime corrects for the time zone and any time zone adjustments (such as Daylight Saving Time in the U.S.A.). After filling in the -.Ft tm +.Li tm structure, .Fn localtime sets the -.Ft tm_isdst +.Fa tm_isdst 'th element of -.Ft tzname +.Fa tzname to a pointer to an ASCII string that's the time zone abbreviation to be used with the return value of @@ -75,7 +77,7 @@ converts to Coordinated Universal Time. .Pp .Fn asctime converts a time value contained in a -.Ft tm +.Li tm structure to a 26-character string, as shown in the above example, and returns a pointer @@ -85,20 +87,20 @@ to the string. converts the broken-down time, expressed as local time, in the structure pointed to by -.Ft tm +.Li tm into a calendar time value with the same encoding as that of the values returned by the .Fn time function. The original values of the -.Ft tm_wday +.Fa tm_wday and -.Ft tm_yday +.Fa tm_yday components of the structure are ignored, and the original values of the other components are not restricted to their normal ranges. (A positive or zero value for -.Ft tm_isdst +.Fa tm_isdst causes .Fn mktime to presume initially that summer time (for example, Daylight Saving Time @@ -106,23 +108,23 @@ in the U.S.A.) respectively, is or is not in effect for the specified time. A negative value for -.Ft tm_isdst +.Fa tm_isdst causes the .Fn mktime function to attempt to divine whether summer time is in effect for the specified time.) On successful completion, the values of the -.Ft tm_wday +.Fa tm_wday and -.Ft tm_yday +.Fa tm_yday components of the structure are set appropriately, and the other components are set to represent the specified calendar time, but with their values forced to their normal ranges; the final value of -.Ft tm_mday +.Fa tm_mday is not set until -.Ft tm_mon +.Fa tm_mon and -.Ft tm_year +.Fa tm_year are determined. .Fn mktime returns the specified calendar time; @@ -131,19 +133,18 @@ it returns \-1. .Pp .Fn difftime returns the difference between two calendar times, -( -.Ft time1 +.Pf ( Fa time1 - -.Ft time0 -), expressed in seconds. +.Fa time0 ) , +expressed in seconds. .Pp Declarations of all the functions and externals, and the -.Ft tm +.Li tm structure, are in the -.Ft <time.h> +.Aq Pa time.h header file. The structure (of type) -.Ft struct tm +.Li struct tm includes the following fields: .Bd -literal -offset indent int tm_sec; /\(** seconds (0 - 60) \(**/ @@ -160,24 +161,24 @@ includes the following fields: .Ed .Pp The -.Ft tm_zone +.Fa tm_zone and -.Ft tm_gmtoff +.Fa tm_gmtoff fields exist, and are filled in, only if arrangements to do so were made when the library containing these functions was created. There is no guarantee that these fields will continue to exist in this form in future releases of this code. .Pp -.Ft tm_isdst +.Fa tm_isdst is non-zero if summer time is in effect. .Pp -.Ft tm_gmtoff +.Fa tm_gmtoff is the offset (in seconds) of the time represented from UTC, with positive values indicating east of the Prime Meridian. .Sh FILES -.Bl -tag -width "/usr/share/zoneinfo/posixrules" +.Bl -tag -width "/usr/share/zoneinfo/posixrules" -compact .It Pa /usr/share/zoneinfo time zone information directory .It Pa /etc/localtime @@ -203,9 +204,9 @@ UTC leap seconds are loaded from The return values point to static data; the data is overwritten by each call. The -.Ft tm_zone +.Fa tm_zone field of a returned -.Ft "struct tm" +.Li struct tm points to a static array of characters, which will also be overwritten at the next call (and by calls to |