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Diffstat (limited to 'lib/libc/stdtime/tzfile.5')
| -rw-r--r-- | lib/libc/stdtime/tzfile.5 | 117 |
1 files changed, 58 insertions, 59 deletions
diff --git a/lib/libc/stdtime/tzfile.5 b/lib/libc/stdtime/tzfile.5 index 1d47033..4bff7de 100644 --- a/lib/libc/stdtime/tzfile.5 +++ b/lib/libc/stdtime/tzfile.5 @@ -1,123 +1,122 @@ -.TH TZFILE 5 -.SH NAME -tzfile \- time zone information -.SH SYNOPSIS -.B -#include <tzfile.h> -.SH DESCRIPTION +.Dd September 13, 1994 +.Dt TZFILE 5 +.Os FreeBSD 2.0 +.Sh NAME +.Nm tzfile +.Nd time zone information +.Sh SYNOPSIS +.Fd #include <tzfile.h> +.Sh DESCRIPTION The time zone information files used by -.IR tzset (3) +.Xr tzset 3 begin with bytes reserved for future use, followed by four four-byte values of type -.BR long , +.Fa long , written in a ``standard'' byte order (the high-order byte of the value is written first). These values are, in order: -.TP -.I tzh_ttisstdcnt +.Pp +.Bl -tag -compact -width tzh_ttisstdcnt +.It Li tzh_ttisstdcnt The number of standard/wall indicators stored in the file. -.TP -.I tzh_leapcnt +.It Li tzh_leapcnt The number of leap seconds for which data is stored in the file. -.TP -.I tzh_timecnt -The number of "transition times" for which data is stored +.It Li tzh_timecnt +The number of ``transition times'' for which data is stored in the file. -.TP -.I tzh_typecnt -The number of "local time types" for which data is stored +.It Li tzh_typecnt +The number of ``local time types'' for which data is stored in the file (must not be zero). -.TP -.I tzh_charcnt -The number of characters of "time zone abbreviation strings" +.It Li tzh_charcnt +The number of characters of ``time zone abbreviation strings'' stored in the file. -.PP +.El +.Pp The above header is followed by -.I tzh_timecnt +.Li tzh_timecnt four-byte values of type -.BR long , +.Fa long , sorted in ascending order. These values are written in ``standard'' byte order. Each is used as a transition time (as returned by -.IR time (2)) +.Xr time 2 ) at which the rules for computing local time change. Next come -.I tzh_timecnt +.Li tzh_timecnt one-byte values of type -.BR "unsigned char" ; +.Fa "unsigned char" ; each one tells which of the different types of ``local time'' types described in the file is associated with the same-indexed transition time. These values serve as indices into an array of -.I ttinfo +.Fa ttinfo structures that appears next in the file; these structures are defined as follows: -.in +.5i -.sp -.nf -.ta .5i +\w'unsigned int\0\0'u +.Pp +.Bd -literal -offset indent struct ttinfo { long tt_gmtoff; int tt_isdst; unsigned int tt_abbrind; }; -.in -.5i -.fi -.sp +.Ed +.Pp Each structure is written as a four-byte value for -.I tt_gmtoff +.Li tt_gmtoff of type -.BR long , +.Fa long , in a standard byte order, followed by a one-byte value for -.I tt_isdst +.Li tt_isdst and a one-byte value for -.IR tt_abbrind . +.Li tt_abbrind . In each structure, -.I tt_gmtoff +.Li tt_gmtoff gives the number of seconds to be added to GMT, -.I tt_isdst +.Li tt_isdst tells whether -.I tm_isdst +.Li tm_isdst should be set by -.I localtime (3) +.Xr localtime 3 and -.I tt_abbrind +.Li tt_abbrind serves as an index into the array of time zone abbreviation characters that follow the -.I ttinfo +.Li ttinfo structure(s) in the file. -.PP +.Pp Then there are -.I tzh_leapcnt +.Li tzh_leapcnt pairs of four-byte values, written in standard byte order; the first value of each pair gives the time (as returned by -.IR time(2)) +.Xr time 2 ) at which a leap second occurs; the second gives the -.I total +.Em total number of leap seconds to be applied after the given time. The pairs of values are sorted in ascending order by time. -.PP +.Pp Finally there are -.I tzh_ttisstdcnt +.Li tzh_ttisstdcnt standard/wall indicators, each stored as a one-byte value; they tell whether the transition times associated with local time types were specified as standard time or wall clock time, and are used when a time zone file is used in handling POSIX-style time zone environment variables. -.PP -.I Localtime +.Pp +.Nm localtime uses the first standard-time -.I ttinfo +.Li ttinfo structure in the file (or simply the first -.I ttinfo +.Li ttinfo structure in the absence of a standard-time structure) if either -.I tzh_timecnt +.Li tzh_timecnt is zero or the time argument is less than the first transition time recorded in the file. -.SH SEE ALSO -newctime(3) +.Sh SEE ALSO +.Xr ctime 3 , +.Xr time2posix 3 , +.Xr zic 8 .\" @(#)tzfile.5 7.2 |
