diff options
Diffstat (limited to 'lib/libc/stdtime/tzfile.5')
-rw-r--r-- | lib/libc/stdtime/tzfile.5 | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/lib/libc/stdtime/tzfile.5 b/lib/libc/stdtime/tzfile.5 deleted file mode 100644 index 1606b5ae8c45..000000000000 --- a/lib/libc/stdtime/tzfile.5 +++ /dev/null @@ -1,152 +0,0 @@ -.\" $FreeBSD$ -.Dd September 13, 1994 -.Dt TZFILE 5 -.Os -.Sh NAME -.Nm tzfile -.Nd timezone information -.Sh SYNOPSIS -.Fd #include \&"/usr/src/lib/libc/stdtime/tzfile.h\&" -.Sh DESCRIPTION -The time zone information files used by -.Xr tzset 3 -begin with the magic characters -.Dq Li TZif -to identify them as -time zone information files, -followed by a character identifying the version of the file's format -(as of 2005, either an ASCII NUL or a '2') -followed by fifteen bytes containing zeroes reserved for future use, -followed by four four-byte values -written in a ``standard'' byte order -(the high-order byte of the value is written first). -These values are, -in order: -.Pp -.Bl -tag -compact -width tzh_ttisstdcnt -.It Va tzh_ttisgmtcnt -The number of UTC/local indicators stored in the file. -.It Va tzh_ttisstdcnt -The number of standard/wall indicators stored in the file. -.It Va tzh_leapcnt -The number of leap seconds for which data is stored in the file. -.It Va tzh_timecnt -The number of ``transition times'' for which data is stored -in the file. -.It Va tzh_typecnt -The number of ``local time types'' for which data is stored -in the file (must not be zero). -.It Va tzh_charcnt -The number of characters of ``time zone abbreviation strings'' -stored in the file. -.El -.Pp -The above header is followed by -.Va tzh_timecnt -four-byte values of type -.Fa long , -sorted in ascending order. -These values are written in ``standard'' byte order. -Each is used as a transition time (as returned by -.Xr time 3 ) -at which the rules for computing local time change. -Next come -.Va tzh_timecnt -one-byte values of type -.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 -.Fa ttinfo -structures (with -.Fa tzh_typecnt -entries) that appears next in the file; -these structures are defined as follows: -.Pp -.Bd -literal -offset indent -struct ttinfo { - long tt_gmtoff; - int tt_isdst; - unsigned int tt_abbrind; -}; -.Ed -.Pp -Each structure is written as a four-byte value for -.Va tt_gmtoff -of type -.Fa long , -in a standard byte order, followed by a one-byte value for -.Va tt_isdst -and a one-byte value for -.Va tt_abbrind . -In each structure, -.Va tt_gmtoff -gives the number of seconds to be added to UTC, -.Li tt_isdst -tells whether -.Li tm_isdst -should be set by -.Xr localtime 3 -and -.Va tt_abbrind -serves as an index into the array of time zone abbreviation characters -that follow the -.Li ttinfo -structure(s) in the file. -.Pp -Then there are -.Va tzh_leapcnt -pairs of four-byte values, written in standard byte order; -the first value of each pair gives the time -(as returned by -.Xr time 3 ) -at which a leap second occurs; -the second gives the -.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 -Then there are -.Va 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 -Finally there are -.Va tzh_ttisgmtcnt -UTC/local indicators, each stored as a one-byte value; -they tell whether the transition times associated with local time types -were specified as UTC or local time, -and are used when a time zone file is used in handling POSIX-style -time zone environment variables. -.Pp -.Nm localtime -uses the first standard-time -.Li ttinfo -structure in the file -(or simply the first -.Li ttinfo -structure in the absence of a standard-time structure) -if either -.Li tzh_timecnt -is zero or the time argument is less than the first transition time recorded -in the file. -.Pp -For version-2-format time zone files, -the above header and data is followed by a second header and data, -identical in format except that eight bytes are used for each -transition time or leap second time. -After the second header and data comes a newline-enclosed, -POSIX-TZ-environment-variable-style string for use in handling instants -after the last transition time stored in the file -(with nothing between the newlines if there is no POSIX representation for -such instants). -.Sh SEE ALSO -.Xr ctime 3 , -.Xr time2posix 3 , -.Xr zic 8 -.\" @(#)tzfile.5 8.3 -.\" This file is in the public domain, so clarified as of -.\" 1996-06-05 by Arthur David Olson. |