rsalz@bbn.com (Rich Salz) (04/02/88)
Submitted-by: Arthur David Olson <elsie!ado>
Posting-number: Volume 14, Issue 30
Archive-name: localtime3/part01
[ NOTE: Since a US daylight savings time change starts today, this
posting is out of order. Vplot will resume after the weekend. -r$ ]
: To unbundle, sh this file
echo 'Patchlevel.h' 1>&2
cat >'Patchlevel.h' <<'End of Patchlevel.h'
/* @(#)Patchlevel.h 4.1 */
#define PATCHLEVEL 1
End of Patchlevel.h
echo 'README' 1>&2
cat >'README' <<'End of README'
@(#)README 4.1
Please send comments or information to
vax2.nlm.nih.gov!elsie!tz
for forwarding to folks interested in time zone matters.
Be sure to read the comments in "Makefile" and make any changes
needed to make things right for your system.
This version of the time zone software uses a new format
(based on the work of Guy Harris, a.k.a guy@sun.UUCP)
for the time zone information files. They are now stored by default in a
directory named "/etc/zoneinfo" rather than "/etc/tzdir" or "/etc/timezones"
as before. If you've already compiled programs with older time zone software,
just leave the "/etc/tzdir" and/or "/etc/timezones" files around until you
have a chance to recompile.
For better compatability with other versions of time conversion functions,
the time zone abbreviation to be used with localtime's return value is now
pointed to by one of the two elements of the (char *) array tzname, rather
than by the (char *) tz_abbr. If you have code that uses tz_abbr, add a
-DTZA_COMPAT
to the end of the
CFLAGS=
line in "Makefile".
To use the new functions, use a "-lz" option when compiling or linking.
Historical local time information has been included here not because it
is particularly useful, but rather to:
* give an idea of the variety of local time rules that have
existed in the past and thus an idea of the variety that may be
expected in the future;
* provide a test of the generality of the local time rule description
system.
The information in the time zone data files is by no means authoritative;
if you know that the rules are different from those in a file, by all means
feel free to change file (and please send the changed version to
vax2.nlm.nih.gov!elsie!tz for use in the future). Europeans take note!
End of README
echo 'Theory' 1>&2
cat >'Theory' <<'End of Theory'
@(#)Theory 4.1
These time and date functions are much like the System V Release 2.0 (SVR2)
time and date functions; there are a few additions and changes to extend
the usefulness of the SVR2 functions:
* In SVR2, time display in a process is controlled by the environment
variable TZ, which "must be a three-letter time zone name, followed
by a number representing the difference between local time and
Greenwich Mean Time in hours, followed by an optional three-letter
name for a daylight time zone;" when the optional daylight time zone is
present, "standard U.S.A. Daylight Savings Time conversion is applied."
This means that SVR2 can't deal with other (for example, Australian)
daylight savings time rules, or situations where more than two
time zone abbreviations are used in an area.
* In SVR2, time conversion information is compiled into each program
that does time conversion. This means that when time conversion
rules change (as in the United States in 1987), all programs that
do time conversion must be recompiled to ensure proper results.
* In SVR2, time conversion fails for near-minimum or near-maximum
time_t values when doing conversions for places that don't use GMT.
* In SVR2, there's no tamper-proof way for a process to learn the
system's best idea of local wall clock. (This is important for
applications that an administrator wants used only at certain times--
without regard to whether the user has fiddled the "TZ" environment
variable. While an administrator can "do everything in GMT" to get
around the problem, doing so is inconvenient and precludes handling
daylight savings time shifts--as might be required to limit phone
calls to off-peak hours.)
* These functions can account for leap seconds, thanks to Bradley White
(bww@k.cs.cmu.edu).
These are the changes that have been made to the SVR2 functions:
* The "TZ" environment variable is used in generating the name of a file
from which time zone information is read; "TZ" is no longer constrained
to be a three-letter time zone name followed by a number of hours and
an optional three-letter daylight time zone name. The daylight saving
time rules to be used for a particular time zone are encoded in the
time zone file; the format of the file allows U.S., Australian, and
other rules to be encoded, and allows for situations where more than
two time zone abbreviations are used.
It was recognized that allowing the "TZ" environment variable to
take on values such as "US/Eastern" might cause "old" programs
(that expect "TZ" to have a certain form) to operate incorrectly;
consideration was given to using some other environment variable
(for example, "TIMEZONE") to hold the string used to generate the
time zone information file name. In the end, however, it was decided
to continue using "TZ": it is widely used for time zone purposes;
separately maintaining both "TZ" and "TIMEZONE" seemed a nuisance;
and systems where "new" forms of "TZ" might cause problems can simply
give time zone files names such as "EST5EDT" which can be used both by
"new" programs (as file names) and "old" programs (as zone names and
offsets).
* To handle places where more than two time zone abbreviations are used,
the functions "localtime" and "gmtime" set tzname[tmp->tm_isdst]
(where "tmp" is the value the function returns) to the time zone
abbreviation to be used. This differs from SVR2, where the elements
of tzname are only changed as a result of calls to tzset.
* Since the "TZ" environment variable can now be used to control time
conversion, the "daylight" and "timezone" variables are no longer
needed or supported. (You can use a compile-time option to cause
these variables to be defined and to be set by "tzset"; however, their
values will not be used by "localtime.")
* The "localtime" function has been set up to deliver correct results
for near-minimum or near-maximum time_t values. (A comment in the
source code tells how to get compatibly wrong results).
* A function "tzsetwall" has been added to arrange for the system's
best approximation to local wall clock time to be delivered by
subsequent calls to "localtime." Source code for portable
applications that "must" run on local wall clock time should call
"tzsetwall();" if such code is moved to "old" systems that don't provide
tzsetwall, you won't be able to generate an executable program.
(These time zone functions also arrange for local wall clock time to be
used if tzset is called--directly or indirectly--and there's no "TZ"
environment variable; portable applications should not, however, rely
on this behavior since it's not the way SVR2 systems behave.)
Points of interest to folks with Version 7 or BSD systems:
* The BSD "timezone" function is not present in this package;
it's impossible to reliably map timezone's arguments (a "minutes west
of GMT" value and a "daylight saving time in effect" flag) to a
time zone abbreviation, and we refuse to guess.
Programs that in the past used the timezone function may now examine
tzname[localtime(&clock)->tm_isdst] to learn the correct time
zone abbreviation to use. Alternatively, use localtime(&clock)->tm_zone
if this has been enabled.
* The BSD gettimeofday function is not used in this package;
this lets users control the time zone used in doing time conversions.
Users who don't try to control things (that is, users who do not set
the environment variable TZ) get the time conversion specified in the
file "/etc/zoneinfo/localtime"; see the time zone compiler writeup for
information on how to initialize this file.
* The BSD "dysize" function is only included if the preprocessor symbol
BSD_COMPAT is defined. For a year y, the BSD code returns the value
((y % 4) == 0) : 366 : 365
while this code returns the value
(((y) % 4) == 0 && ((y) % 100) != 0 || ((y) % 400) == 0) ? 366 : 365
There's a comment in the code telling how to get the BSD value.
The functions that are conditionally compiled if STD_INSPIRED is defined should,
at this point, be looked on primarily as food for thought. They are not in
any sense "standard compatible"--some are not, in fact, specified in *any*
standard. They do, however, represent responses of various authors to
standardization proposals.
Other time conversion proposals, in particular the one developed by folks at
Hewlett Packard, offer a wider selection of functions that provide capabilities
beyond those provided here. The absence of such functions from this package
is not meant to discourage the development, standardization, or use of such
functions. Rather, their absence reflects the decision to make this package
close to SVR2 (with the exceptions outlined above) to ensure its broad
acceptability. If more powerful time conversion functions can be standardized,
so much the better.
It's probably not wise to standardize everything in this package.
While the command
nroff -man newctime.3
produces a document that describes this package, the command
nroff -man -rX3J11 newctime.3
produces a document that describes the "standardizable" parts.
End of Theory
echo 'newctime.3' 1>&2
cat >'newctime.3' <<'End of newctime.3'
.TH NEWCTIME 3
.SH NAME
ctime, localtime, gmtime, asctime, tzset, tzsetwall \- convert date and time to ASCII
.SH SYNOPSIS
.nf
.B extern char *tzname[2];
.PP
.B void tzset()
.PP
.B void tzsetwall()
.PP
.B char *ctime(clock)
.B long *clock;
.PP
.B #include <time.h>
.PP
.B char *asctime(tm)
.B struct tm *tm;
.PP
.B struct tm *localtime(clock)
.B long *clock;
.PP
.B struct tm *gmtime(clock)
.B long *clock;
.if !\nX \{\
.PP
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 \nX \{\
IF
.B TZ
is absent from the environment,
the behavior is implementation defined.
If
.B TZ
does appear in the environment,
.I localtime
will only work correctly if
its value is one of an
implementation-defined set of values.
\}
.if !\nX \{\
If
.B TZ
does not appear in the environment,
the best available approximation to local wall clock time is used by
.IR localtime .
If
.B TZ
appears in the environment but its value is a null string,
Greenwich Mean Time is used (without leap second correction);
if
.B TZ
appears and
begins with a slash,
it is used as the absolute pathname of the
.IR tzfile (5)-format
file from which to read the time conversion information;
if
.B TZ
appears and
begins with a character other than a slash,
it's used as a pathname relative to a system time conversion information
directory.
\}
.PP
.I Tzsetwall
sets things up so that
.I localtime
returns the best available approximation of local wall clock time.
.PP
.I Ctime\^
converts a long integer, pointed to by
.IR clock ,
representing the time in seconds since
00:00:00 GMT, January 1, 1970,
and returns a pointer to a
26-character string
of the form
.br
.ce
Thu Nov 24 18:22:48 1986\\n\\0
.br
All the fields have constant width.
.PP
.IR Localtime\^
and
.I gmtime\^
return pointers to ``tm'' structures, described below.
.I Localtime\^
corrects for the time zone and any time zone adjustments
(such as Daylight Saving Time in the U.S.A.).
.if \nX Whether, before doing so,
.if !\nX Before doing so,
.I localtime\^
calls
.I tzset\^
(if
.I tzset\^
has not been called in
.if \nX the current process) is implementation defined.
.if !\nX the current process).
.if !\nX \{\
After filling in the ``tm'' structure,
.I localtime
sets the
.BR tm_isdst 'th
element of
.B tzname
to a pointer to an
ASCII string that's the time zone abbreviation to be used with
.IR localtime 's
return value.
\}
.PP
.I Gmtime\^
converts to Greenwich Mean Time (GMT).
.PP
.I Asctime\^
converts a time value contained in a
``tm'' structure to a 26-character string,
as shown in the above example,
and returns a pointer
to the string.
.PP
Declarations of all the functions and externals, and the ``tm'' structure,
are in the
.B <time.h>\^
header file.
The structure (of type)
.B struct tm
includes the following fields:
.RS
.PP
.nf
.ta .5i +\w'long tm_gmtoff;\0\0'u
int tm_sec; /\(** seconds (0 - 60) \(**/
int tm_min; /\(** minutes (0 - 59) \(**/
int tm_hour; /\(** hours (0 - 23) \(**/
int tm_mday; /\(** day of month (1 - 31) \(**/
int tm_mon; /\(** month of year (0 - 11) \(**/
int tm_year; /\(** year \- 1900 \(**/
int tm_wday; /\(** day of week (Sunday = 0) \(**/
int tm_yday; /\(** day of year (0 - 365) \(**/
int tm_isdst; /\(** is DST in effect? \(**/
char \(**tm_zone; /\(** abbreviation of timezone name \(**/
long tm_gmtoff; /\(** offset from GMT in seconds \(**/
.fi
.RE
.PP
The
.I tm_zone
and
.I 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
.I Tm_isdst\^
is non-zero if a
time zone adjustment such as Daylight Saving Time
is in effect.
.PP
.I Tm_gmtoff
is the offset (in seconds) of the time represented
from GMT, with positive values indicating East
of Greenwich.
.if !\nX \{\
.SH FILES
.ta \w'/etc/zoneinfo/localtime\0\0'u
/etc/zoneinfo time zone information directory
.br
/etc/zoneinfo/localtime local time zone file
\}
.br
/etc/zoneinfo/GMT GMT file (needed for leap seconds)
.SH SEE ALSO
.if !\nX tzfile(5),
getenv(3),
time(2)
.SH NOTE
The return values point to static data
whose content is overwritten by each call.
The
.B tm_zone
field of a returned
.B "struct tm"
points to a static array of characters, which
will also be overwritten at the next call
(and by calls to
.I tzset
or
.IR tzsetwall ).
.. @(#)newctime.3 4.1
End of newctime.3
echo 'tzfile.5' 1>&2
cat >'tzfile.5' <<'End of tzfile.5'
.TH TZFILE 5
.SH NAME
tzfile \- time zone information
.SH SYNOPSIS
.B
#include <tzfile.h>
.SH DESCRIPTION
The time zone information files used by
.IR tzset (3)
begin with bytes reserved for future use,
followed by four four-byte values of type
.BR 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_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
in the file.
.TP
.I 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"
stored in the file.
.PP
The above header is followed by
.I tzh_timecnt
four-byte values of type
.BR 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))
at which the rules for computing local time change.
Next come
.I tzh_timecnt
one-byte values of type
.BR "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
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
struct ttinfo {
long tt_gmtoff;
int tt_isdst;
unsigned int tt_abbrind;
};
.in -.5i
.fi
.sp
Each structure is written as a four-byte value for
.I tt_gmtoff
of type
.BR long ,
in a standard byte order, followed by a one-byte value for
.I tt_isdst
and a one-byte value for
.IR tt_abbrind .
In each structure,
.I tt_gmtoff
gives the number of seconds to be added to GMT,
.I tt_isdst
tells whether
.I tm_isdst
should be set by
.I localtime (3)
and
.I tt_abbrind
serves as an index into the array of time zone abbreviation characters
that follow the
.I ttinfo
structure(s) in the file.
.PP
Finally, there are
.I 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))
at which a leap second occurs;
the second gives the
.I total
number of leap seconds to be applied after the given time.
The pairs of values are sorted in ascending order by time.
.PP
.I Localtime
uses the first standard-time
.I ttinfo
structure in the file
(or simply the first
.I ttinfo
structure in the absence of a standard-time structure)
if either
.I tzh_timecnt
is zero or the time argument is less than the first transition time recorded
in the file.
.SH SEE ALSO
newctime(3)
.. @(#)tzfile.5 4.1
End of tzfile.5
echo 'zic.8' 1>&2
cat >'zic.8' <<'End of zic.8'
.TH ZIC 8
.SH NAME
zic \- time zone compiler
.SH SYNOPSIS
.B zic
[
.B \-v
] [
.B \-d
.I directory
] [
.B \-l
.I localtime
] [
.B \-L
.I leapsecondfilename
] [
.B \-s
] [
.I filename
\&... ]
.SH DESCRIPTION
.if t .ds lq ``
.if t .ds rq ''
.if n .ds lq \&"\"
.if n .ds rq \&"\"
.de q
\\$3\*(lq\\$1\*(rq\\$2
..
.I Zic
reads text from the file(s) named on the command line
and creates the time conversion information files specified in this input.
If a
.I filename
is
.BR \- ,
the standard input is read.
.PP
These options are available:
.TP
.BI "\-d " directory
Create time conversion information files in the named directory rather than
in the standard directory named below.
.TP
.BI "\-l " timezone
Use the given time zone as local time.
.I Zic
will act as if the file contained a link line of the form
.sp
.ti +.5i
Link \fItimezone\fP localtime
.TP
.BI "\-L " leapsecondfilename
Read leap second information from the file with the given name.
If this option is not used,
leap second information is read from a file named "leapseconds".
.TP
.B \-v
Complain if a year that appears in a data file is outside the range
of years representable by
.IR time (2)
values.
.TP
.B \-s
Limit time values stored in output files to values that are the same
whether they're taken to be signed or unsigned.
You can use this option to generate SVVS-compatible files.
.sp
Input lines are made up of fields.
Fields are separated from one another by any number of white space characters.
Leading and trailing white space on input lines is ignored.
An unquoted sharp character (#) in the input introduces a comment which extends
to the end of the line the sharp character appears on.
White space characters and sharp characters may be enclosed in double quotes
(") if they're to be used as part of a field.
Any line that is blank (after comment stripping) is ignored.
Non-blank lines are expected to be of one of three types:
rule lines, zone lines, and link lines.
.PP
A rule line has the form
.nf
.B
.ti +.5i
.ta \w'Rule\0\0'u +\w'NAME\0\0'u +\w'FROM\0\0'u +\w'1973\0\0'u +\w'TYPE\0\0'u +\w'Apr\0\0'u +\w'lastSun\0\0'u +\w'2:00\0\0'u +\w'SAVE\0\0'u
.sp
Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
.sp
For example:
.ti +.5i
.sp
Rule USA 1969 1973 \- Apr lastSun 2:00 1:00 D
.sp
.fi
The fields that make up a rule line are:
.TP "\w'LETTER/S'u"
.B NAME
Gives the (arbitrary) name of the set of rules this rule is part of.
.TP
.B FROM
Gives the first year in which the rule applies.
The word
.B minimum
(or an abbreviation) means the minimum year with a representable time value.
The word
.B maximum
(or an abbreviation) means the maximum year with a representable time value.
.TP
.B TO
Gives the final year in which the rule applies.
In addition to
.B minimum
and
.B maximum
(as above),
the word
.B only
(or an abbreviation)
may be used to repeat the value of the
.B FROM
field.
.TP
.B TYPE
Gives the type of year in which the rule applies.
If
.B TYPE
is
.B \-
then the rule applies in all years between
.B FROM
and
.B TO
inclusive;
if
.B TYPE
is
.BR uspres ,
the rule applies in U.S. Presidential election years;
if
.B TYPE
is
.BR nonpres ,
the rule applies in years other than U.S. Presidential election years.
If
.B TYPE
is something else, then
.I zic
executes the command
.ti +.5i
\fByearistype\fP \fIyear\fP \fItype\fP
.br
to check the type of a year:
an exit status of zero is taken to mean that the year is of the given type;
an exit status of one is taken to mean that the year is not of the given type.
.TP
.B IN
Names the month in which the rule takes effect.
Month names may be abbreviated.
.TP
.B ON
Gives the day on which the rule takes effect.
Recognized forms include:
.nf
.in +.5i
.sp
.ta \w'Sun<=25\0\0'u
5 the fifth of the month
lastSun the last Sunday in the month
lastMon the last Monday in the month
Sun>=8 first Sunday on or after the eighth
Sun<=25 last Sunday on or before the 25th
.fi
.in -.5i
.sp
Names of days of the week may be abbreviated or spelled out in full.
Note that there must be no spaces within the
.B ON
field.
.TP
.B AT
Gives the time of day at which the rule takes effect.
Recognized forms include:
.nf
.in +.5i
.sp
.ta \w'1:28:13\0\0'u
2 time in hours
2:00 time in hours and minutes
15:00 24-hour format time (for times after noon)
1:28:14 time in hours, minutes, and seconds
.fi
.in -.5i
.sp
Any of these forms may be followed by the letter
.B w
if the given time is local
.q "wall clock"
time or
.B s
if the given time is local
.q standard
time; in the absence of
.B w
or
.BR s ,
wall clock time is assumed.
.TP
.B SAVE
Gives the amount of time to be added to local standard time when the rule is in
effect.
This field has the same format as the
.B AT
field
(although, of course, the
.B w
and
.B s
suffixes are not used).
.TP
.B LETTER/S
Gives the
.q "variable part"
(for example, the
.q S
or
.q D
in
.q EST
or
.q EDT )
of time zone abbreviations to be used when this rule is in effect.
If this field is
.BR \- ,
the variable part is null.
.PP
A zone line has the form
.sp
.nf
.ti +.5i
.ta \w'Zone\0\0'u +\w'Australia/South\-west\0\0'u +\w'GMTOFF\0\0'u +\w'RULES/SAVE\0\0'u +\w'FORMAT\0\0'u
Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL]
.sp
For example:
.sp
.ti +.5i
Zone Australia/South\-west 9:30 Aus CST 1987 Mar 15 2:00
.sp
.fi
The fields that make up a zone line are:
.TP "\w'GMTOFF'u"
.B NAME
The name of the time zone.
This is the name used in creating the time conversion information file for the
zone.
.TP
.B GMTOFF
The amount of time to add to GMT to get standard time in this zone.
This field has the same format as the
.B AT
and
.B SAVE
fields of rule lines;
begin the field with a minus sign if time must be subtracted from GMT.
.TP
.B RULES/SAVE
The name of the rule(s) that apply in the time zone or,
alternately, an amount of time to add to local standard time.
If this field is
.B \-
then standard time always applies in the time zone.
.TP
.B FORMAT
The format for time zone abbreviations in this time zone.
The pair of characters
.B %s
is used to show where the
.q "variable part"
of the time zone abbreviation goes.
.TP
.B UNTIL
The time at which the GMT offset or the rule(s) change for a location.
It is specified as a year, a month, a day, and a time of day.
If this is specified,
the time zone information is generated from the given GMT offset
and rule change until the time specified.
.IP
The next line must be a
.q continuation
line; this has the same form as a zone line except that the
string
.q Zone
and the name are omitted, as the continuation line will
place information starting at the time specified as the
.B UNTIL
field in the previous line in the file used by the previous line.
Continuation lines may contain an
.B UNTIL
field, just as zone lines do, indicating that the next line is a further
continuation.
.PP
A link line has the form
.sp
.nf
.ti +.5i
.if t .ta \w'Link\0\0'u +\w'LINK-FROM\0\0'u
.if n .ta \w'Link\0\0'u +\w'US/Eastern\0\0'u
Link LINK-FROM LINK-TO
.sp
For example:
.sp
.ti +.5i
Link US/Eastern EST5EDT
.sp
.fi
The
.B LINK-FROM
field should appear as the
.B NAME
field in some zone line;
the
.B LINK-TO
field is used as an alternate name for that zone.
.PP
Except for continuation lines,
lines may appear in any order in the input.
.PP
Lines in the file that describes leap seconds have the following form:
.nf
.B
.ti +.5i
.ta \w'Leap\0\0'u +\w'YEAR\0\0'u +\w'MONTH\0\0'u +\w'DAY\0\0'u +\w'HH:MM:SS\0\0'u +\w'CORR\0\0'u
Leap YEAR MONTH DAY HH:MM:SS CORR R/S
.sp
For example:
.ti +.5i
.sp
Leap 1974 Dec 31 23:59:60 + S
.sp
.fi
The
.BR YEAR ,
.BR MONTH ,
.BR DAY ,
and
.B HH:MM:SS
fields tell when the leap second happened.
The
.B CORR
field
should be
.q +
if a second was added
or
.q -
if a second was skipped.
The
.B R/S
field
should be (an abbreviaton of)
.q Stationary
if the leap second time given by the other fields should be interpreted as GMT
or
(an abbreviation of)
.q Rolling
if the leap second time given by the other fields should be interpreted as
local wall clock time.
.SH NOTE
For areas with more than two types of local time,
you may need to use local standard time in the
.B AT
field of the earliest transition time's rule to ensure that
the earliest transition time recorded in the compiled file is correct.
.SH FILES
.ta \w'/etc/zoneinfo\0\0'u
/etc/zoneinfo standard directory used for created files
leapseconds default leap second information file
.SH "SEE ALSO"
newctime(3), tzfile(5), zdump(8)
.. @(#)zic.8 4.1
End of zic.8
echo 'zdump.8' 1>&2
cat >'zdump.8' <<'End of zdump.8'
.TH ZDUMP 8
.SH NAME
zdump \- time zone dumper
.SH SYNOPSIS
.B zdump
[
.B \-v
] [
.B \-c
cutoffyear ] [ zonename ... ]
.SH DESCRIPTION
.I Zdump
prints the current time in each
.I zonename
named on the command line.
.PP
These options are available:
.TP
.B \-v
For each
.I zonename
on the command line,
print the current time,
the time at the lowest possible time value,
the time one day after the lowest possible time value,
the times both one second before and exactly at
each time at which the rules for computing local time change,
the times one second before and exactly at and one second after
each leap second,
the time at one day less than the highest possible time value,
and the time at the highest possible time value,
Each line ends with
.B isdst=1
if the given time is Daylight Saving Time or
.B isdst=0
otherwise.
.TP
.BI "\-c " cutoffyear
Cut off the verbose output near the start of the given year.
.SH FILES
/etc/zoneinfo standard zone information directory
.SH "SEE ALSO"
newctime(3), tzfile(5), zic(8)
.. @(#)zdump.8 4.1
End of zdump.8
echo 'Makefile' 1>&2
cat >'Makefile' <<'End of Makefile'
# @(#)Makefile 4.1
# If you want something other than Eastern United States time used on your
# system, change the line below (after finding the zone you want in the
# time zone files, or adding it to a time zone file).
# Alternately, if you discover you've got the wrong time zone, you can just
# zic -l rightzone
LOCALTIME= US/Eastern
# Use an absolute path name for TZDIR unless you're just testing the software.
TZDIR= /etc/zoneinfo
# You may want to change this define if you're just testing the software.
# Alternatively, you can put these functions in /lib/libc.a, removing
# the old "ctime.o" (and "timezone.o" on a BSD system). This is the
# ideal solution if you are able. Build libz.a, extract the files, and
# then add them to libc.a.
TZLIB= /usr/lib/libz.a
# If you don't want leap second correction done, change "leapseconds" to
# /dev/null below.
LEAPSECONDS= leapseconds
# If you're running on a System V-style system and don't want lint grief,
# add
# -DUSG
# to the end of the "CFLAGS=" line.
#
# If you're running on a system where "strchr" is known as "index",
# (for example, a 4.[012]BSD system), add
# -Dstrchr=index
# to the end of the "CFLAGS=" line.
#
# If you want to use System V compatibility code, add
# -DUSG_COMPAT
# to the end of the "CFLAGS=" line.
#
# If you want BSD compatibility code, add
# -DBSD_COMPAT
# to the end of the "CFLAGS=" line.
#
# If you've used older versions of this software and want "tz_abbr"
# compatibility code, add
# -DTZA_COMPAT
# to the end of the "CFLAGS=" line.
#
# If you'd like to use Robert Elz's additions to the "struct tm" structure,
# add a
# -DKRE_COMPAT
# to the end of the "CFLAGS=" line, and add the structure elements
# long tm_gmtoff;
# char * tm_zone;
# to the END of the "struct tm" structure defined in "/usr/include/time.h".
#
# If you want code inspired by certain emerging standards, add
# -DSTD_INSPIRED
# to the end of the "CFLAGS=" line.
#
# If you want Source Code Control System ID's left out of object modules, add
# -DNOID
# to the end of the "CFLAGS=" line.
#
# If you'll never want to handle solar-time-based time zones, add
# -DNOSOLAR
# to the end of the "CFLAGS=" line
# (and comment out the "SDATA=" line below).
CFLAGS=
# LINTFLAGS is set for 4.[123]BSD systems.
# If you're using System V, you'll want to comment out the "LINTFLAGS=" line.
LINTFLAGS= -phbaaxc
SHAR= shar
################################################################################
CC= cc -DTZDIR=\"$(TZDIR)\"
TZCSRCS= zic.c localtime.c asctime.c \
scheck.c ialloc.c emkdir.c getopt.c link.c
TZCOBJS= zic.o localtime.o asctime.o \
scheck.o ialloc.o emkdir.o getopt.o link.o
TZDSRCS= zdump.c localtime.c asctime.c \
ialloc.c getopt.c link.c
TZDOBJS= zdump.o localtime.o asctime.o \
ialloc.o getopt.o link.o
LIBSRCS= localtime.c asctime.c ctime.c dysize.c timemk.c
LIBOBJS= localtime.o asctime.o ctime.o dysize.o timemk.o
DOCS= Patchlevel.h \
README Theory \
newctime.3 tzfile.5 zic.8 zdump.8 \
Makefile Makefile.tc
SOURCES= tzfile.h nonstd.h stdio.h stdlib.h time.h \
zic.c zdump.c \
localtime.c asctime.c ctime.c dysize.c timemk.c \
scheck.c ialloc.c emkdir.c getopt.c link.c
YDATA= africa antarctica asia australasia \
europe northamerica southamerica pacificnew
NDATA= systemv
SDATA= solar87 solar88
DATA= $(YDATA) $(NDATA) $(SDATA) leapseconds
ENCHILADA= $(DOCS) $(SOURCES) $(DATA)
all: REDID_BINARIES zdump $(TZLIB)
REDID_BINARIES: zic $(DATA)
./zic -d $(TZDIR) -L $(LEAPSECONDS) $(YDATA)
./zic -d $(TZDIR) -L $(LEAPSECONDS) $(SDATA)
./zic -d $(TZDIR) -L /dev/null $(NDATA)
./zic -d $(TZDIR) -l $(LOCALTIME)
touch $@
zdump: $(TZDOBJS)
$(CC) $(CFLAGS) $(LFLAGS) $(TZDOBJS) -o $@
$(TZLIB): $(LIBOBJS)
ar ru $@ $(LIBOBJS)
test -f /usr/bin/ranlib && ranlib $@
zic: $(TZCOBJS)
$(CC) $(CFLAGS) $(LFLAGS) $(TZCOBJS) -o $@
SHARS: SHAR1 SHAR2 SHAR3
SHAR1: $(DOCS)
$(SHAR) $(DOCS) > $@
SHAR2: $(SOURCES)
$(SHAR) $(SOURCES) > $@
SHAR3: $(DATA)
$(SHAR) $(DATA) > $@
tz.shar.Z.uue: $(ENCHILADA)
$(SHAR) $(ENCHILADA) | compress | uuencode tz.shar.Z > $@
$(ENCHILADA):
sccs get $(REL) $(REV) $@
sure: $(SOURCES)
lint $(LINTFLAGS) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(TZCSRCS)
lint $(LINTFLAGS) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(TZDSRCS)
lint $(LINTFLAGS) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(LIBSRCS)
LINTUCB= PATH=/usr/ucb:/bin:/usr/bin lint -phbaaxc
LINT5BIN= PATH=/usr/5bin lint -phbaax
SURE: sure
$(LINTUCB) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(TZCSRCS)
$(LINTUCB) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(TZDSRCS)
$(LINTUCB) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(LIBSRCS)
$(LINT5BIN) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(TZCSRCS)
$(LINT5BIN) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(TZDSRCS)
$(LINT5BIN) $(CFLAGS) -DTZDIR=\"$(TZDIR)\" $(LIBSRCS)
clean:
rm -f core *.o *.out REDID_BINARIES zdump zic \
SHAR* tz.shar.Z.uue ,*
CLEAN: clean
sccs clean
names:
@echo $(ENCHILADA)
asctime.o: nonstd.h stdio.h time.h tzfile.h
ctime.o: nonstd.h time.h
dysize.o: tzfile.h
emkdir.o: nonstd.h stdlib.h
ialloc.o: nonstd.h stdlib.h
link.o: nonstd.h stdio.h
localtime.o: nonstd.h stdio.h stdlib.h time.h tzfile.h
scheck.o: nonstd.h stdio.h stdlib.h
timemk.o: nonstd.h time.h tzfile.h
zdump.o: nonstd.h stdio.h stdlib.h time.h tzfile.h
zic.o: nonstd.h stdio.h stdlib.h time.h tzfile.h
End of Makefile
echo 'Makefile.tc' 1>&2
cat >'Makefile.tc' <<'End of Makefile.tc'
# @(#)Makefile.tc 4.1
# If you want something other than Eastern United States time used on your
# system, change the line below (after finding the zone you want in the
# time zone files, or adding it to a time zone file).
# Alternately, if you discover you've got the wrong time zone, you can just
# zic -l rightzone
LOCALTIME= US/Eastern
# Use an absolute path name for TZDIR unless you're just testing the software.
# Forward slashes, please!
TZDIR= c:/etc/zoneinfo
# You may want to change this define if you're just testing the software.
# Backward slashes, please!
TZLIB= c:\turboc\lib\z.lib
# If you don't want leap second correction done, change "leapseconds" to
# nul below.
LEAPSECONDS= leapseconds
# If you want to use System V compatibility code, add
# -DUSG_COMPAT
# to the end of the "CFLAGS=" line.
#
# If you want BSD compatibility code, add
# -DBSD_COMPAT
# to the end of the "CFLAGS=" line.
#
# If you'd like to use Robert Elz's additions to the "struct tm" structure,
# add a
# -DKRE_COMPAT
# to the end of the "CFLAGS=" line, and add the structure elements
# long tm_gmtoff;
# char * tm_zone;
# to the END of the "struct tm" structure defined in <time.h>.
#
# If you want code inspired by certain emerging standards, add
# -DSTD_INSPIRED
# to the end of the "CFLAGS=" line.
#
# If you want Source Code Control System ID's left out of object modules, add
# -DNOID
# to the end of the "CFLAGS=" line.
#
# If you'll never want to handle solar-time-based time zones, add
# -DNOSOLAR
# to the end of the "CFLAGS=" line
# (and comment out the "SDATA=" line below).
CFLAGS=
################################################################################
# Need -mc so solar87 and solar88 can be handled.
# Need -A to get __STDC__ defined (and PC-specific nonsense dispensed with).
CC= tcc -DTZDIR="$(TZDIR)" -mc -A
TZCSRCS= zic.c localtime.c asctime.c \
scheck.c ialloc.c emkdir.c getopt.c link.c
TZCOBJS= zic.obj localtime.obj asctime.obj \
scheck.obj ialloc.obj emkdir.obj getopt.obj link.obj
TZDSRCS= zdump.c localtime.c asctime.c \
ialloc.c getopt.c link.c
TZDOBJS= zdump.obj localtime.obj asctime.obj \
ialloc.obj getopt.obj link.obj
LIBSRCS= localtime.c asctime.c ctime.c dysize.c timemk.c
LIBOBJS= localtime.obj asctime.obj ctime.obj dysize.obj timemk.obj
YDATA= africa antarctica asia australasia \
europe northamerica southamerica pacificnew
NDATA= systemv
SDATA= solar87 solar88
DATA= $(YDATA) $(NDATA) $(SDATA) leapseconds
all: REDID_BINARIES zdump.exe $(TZLIB)
REDID_BINARIES: zic.exe $(DATA)
zic -d $(TZDIR) -L $(LEAPSECONDS) $(YDATA)
zic -d $(TZDIR) -L $(LEAPSECONDS) $(SDATA)
zic -d $(TZDIR) -L nul $(NDATA)
zic -d $(TZDIR) -l $(LOCALTIME)
copy Makefile $<
touch $<
zdump.exe: $(TZDOBJS)
$(CC) $(CFLAGS) $(LFLAGS) $(TZDOBJS)
$(TZLIB): z.lib
copy z.lib $<
z.lib: $(LIBOBJS)
copy nul $<
command /c for %i in ($(LIBOBJS)) do tlib $< +%i
zic.exe: $(TZCOBJS)
$(CC) $(CFLAGS) $(LFLAGS) $(TZCOBJS)
clean:
command /c for %i in (obj exe lib bak) do \
if exist *.%i del *.%i
command /c if exist REDID_BINARIES do del REDID_BINARIES
.c.obj:
$(CC) -c $(CFLAGS) $*
asctime.obj: nonstd.h stdio.h time.h tzfile.h
ctime.obj: nonstd.h time.h
dysize.obj: tzfile.h
emkdir.obj: nonstd.h stdlib.h
ialloc.obj: nonstd.h stdlib.h
link.obj: nonstd.h stdio.h
localtime.obj: nonstd.h stdio.h stdlib.h time.h tzfile.h
scheck.obj: nonstd.h stdio.h stdlib.h
timemk.obj: nonstd.h time.h tzfile.h
zdump.obj: nonstd.h stdio.h stdlib.h time.h tzfile.h
zic.obj: nonstd.h stdio.h stdlib.h time.h tzfile.h
End of Makefile.tc
exit
--
Please send comp.sources.unix-related mail to rsalz@uunet.uu.net.