From 409fb97c98076952153378e317f6c8da0023b0a1 Mon Sep 17 00:00:00 2001 From: Arthur David Olson Date: Thu, 17 Jan 1991 19:07:51 -0500 Subject: [PATCH] tzset separated out SCCS-file: newctime.3 SCCS-SID: 7.6 --- newctime.3 | 213 +---------------------------------------------------- 1 file changed, 4 insertions(+), 209 deletions(-) diff --git a/newctime.3 b/newctime.3 index 4370edf..b16837c 100644 --- a/newctime.3 +++ b/newctime.3 @@ -1,6 +1,6 @@ .TH NEWCTIME 3 .SH NAME -asctime, ctime, difftime, gmtime, localtime, mktime, tzset \- convert date and time to ASCII +asctime, ctime, difftime, gmtime, localtime, mktime \- convert date and time to ASCII .SH SYNOPSIS .nf .B extern char *tzname[2]; @@ -33,212 +33,6 @@ asctime, ctime, difftime, gmtime, localtime, mktime, tzset \- convert date and t .B cc ... -lz .fi .SH DESCRIPTION -.I Tzset -uses the value of the environment variable -.B TZ -to set time conversion information used by -.IR localtime . -If -.B TZ -does not appear in the environment, -the best available approximation to local wall clock time, as specified -by the -.IR tzfile (5)-format -file -.B localtime -in the system time conversion information directory, is used by -.IR localtime . -If -.B TZ -appears in the environment but its value is a null string, -Coordinated Universal Time (UTC) is used (without leap second -correction). If -.B TZ -appears in the environment and its value is not a null string: -.IP -if the value begins with a colon, it is used as a pathname of a file -from which to read the time conversion information; -.IP -if the value does not begin with a colon, it is first used as the -pathname of a file from which to read the time conversion information, -and, if that file cannot be read, is used directly as a specification of -the time conversion information. -.PP -When -.B TZ -is used as a pathname, if it begins with a slash, -it is used as an absolute pathname; otherwise, -it is used as a pathname relative to a system time conversion information -directory. -The file must be in the format specified in -.IR tzfile (5). -.PP -When -.B TZ -is used directly as a specification of the time conversion information, -it must have the following syntax (spaces inserted for clarity): -.IP -\fIstd\|offset\fR[\fIdst\fR[\fIoffset\fR][\fB,\fIrule\fR]] -.PP -Where: -.RS -.TP 15 -.IR std " and " dst -Three or more bytes that are the designation for the standard -.RI ( std ) -or summer -.RI ( dst ) -time zone. Only -.I std -is required; if -.I dst -is missing, then summer time does not apply in this locale. -Upper- and lowercase letters are explicitly allowed. Any characters -except a leading colon -.RB ( : ), -digits, comma -.RB ( , ), -minus -.RB ( \(mi ), -plus -.RB ( \(pl ), -and ASCII NUL are allowed. -.TP -.I offset -Indicates the value one must add to the local time to arrive at -Coordinated Universal Time. The -.I offset -has the form: -.RS -.IP -\fIhh\fR[\fB:\fImm\fR[\fB:\fIss\fR]] -.RE -.IP -The minutes -.RI ( mm ) -and seconds -.RI ( ss ) -are optional. The hour -.RI ( hh ) -is required and may be a single digit. The -.I offset -following -.I std -is required. If no -.I offset -follows -.IR dst , -summer time is assumed to be one hour ahead of standard time. One or -more digits may be used; the value is always interpreted as a decimal -number. The hour must be between zero and 24, and the minutes (and -seconds) \(em if present \(em between zero and 59. If preceded by a -.RB `` \(mi '', -the time zone shall be east of the Prime Meridian; otherwise it shall be -west (which may be indicated by an optional preceding -.RB `` \(pl ''). -.TP -.I rule -Indicates when to change to and back from summer time. The -.I rule -has the form: -.RS -.IP -\fIdate\fB/\fItime\fB,\fIdate\fB/\fItime\fR -.RE -.IP -where the first -.I date -describes when the change from standard to summer time occurs and the -second -.I date -describes when the change back happens. Each -.I time -field describes when, in current local time, the change to the other -time is made. -.IP -The format of -.I date -is one of the following: -.RS -.TP 10 -.BI J n -The Julian day -.I n -.RI "(1\ \(<=" "\ n\ " "\(<=\ 365). -Leap days are not counted; that is, in all years \(em including leap -years \(em February 28 is day 59 and March 1 is day 60. It is -impossible to explicitly refer to the occasional February 29. -.TP -.I n -The zero-based Julian day -.RI "(0\ \(<=" "\ n\ " "\(<=\ 365). -Leap days are counted, and it is possible to refer to February 29. -.TP -.BI M m . n . d -The -.IR d' th -day -.RI "(0\ \(<=" "\ d\ " "\(<=\ 6) -of week -.I n -of month -.I m -of the year -.RI "(1\ \(<=" "\ n\ " "\(<=\ 5, -.RI "1\ \(<=" "\ m\ " "\(<=\ 12, -where week 5 means ``the last -.I d -day in month -.IR m '' -which may occur in either the fourth or the fifth week). Week 1 is the -first week in which the -.IR d' th -day occurs. Day zero is Sunday. -.RE -.IP "" 15 -The -.I time -has the same format as -.I offset -except that no leading sign -.RB (`` \(mi '' -or -.RB `` \(pl '') -is allowed. The default, if -.I time -is not given, is -.BR 02:00:00 . -.RE -.LP -If no -.I rule -is present in -.BR TZ , -the rules specified -by the -.IR tzfile (5)-format -file -.B posixrules -in the system time conversion information directory are used, with the -standard and summer time offsets from UTC replaced by those specified by -the -.I offset -values in -.BR TZ . -.PP -For compatibility with System V Release 3.1, a semicolon -.RB ( ; ) -may be used to separate the -.I rule -from the rest of the specification. -.PP -If the -.B TZ -environment variable does not specify a -.IR tzfile (5)-format -and cannot be interpreted as a direct specification, -UTC is used. -.PP .I Ctime\^ converts a long integer, pointed to by .IR clock , @@ -404,9 +198,10 @@ is absent, UTC leap seconds are loaded from .BR /usr/local/etc/zoneinfo/posixrules . .SH SEE ALSO -tzfile(5), getenv(3), -time(2) +newtzset(3), +time(2), +tzfile(5) .SH NOTES The return values point to static data whose content is overwritten by each call.