f14fb60209
* Updating common/lib * Updating lib/csu * Updating lib/libc * Updating libexec/ld.elf_so * Corrected test on __minix in featuretest to actually follow the meaning of the comment. * Cleaned up _REENTRANT-related defintions. * Disabled -D_REENTRANT for libfetch * Removing some unneeded __NBSD_LIBC defines and tests Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
94 lines
4.1 KiB
Plaintext
94 lines
4.1 KiB
Plaintext
README for the tz distribution
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This file is in the public domain, so clarified as of
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2009-05-17 by Arthur David Olson.
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"What time is it?" -- Richard Deacon as The King
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"Any time you want it to be." -- Frank Baxter as The Scientist
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(from the Bell System film "About Time")
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The 1989 update of the time zone package featured
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* POSIXization (including interpretation of POSIX-style TZ environment
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variables, provided by Guy Harris),
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* ANSIfication (including versions of "mktime" and "difftime"),
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* SVIDulation (an "altzone" variable)
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* MACHination (the "gtime" function)
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* corrections to some time zone data (including corrections to the rules
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for Great Britain and New Zealand)
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* reference data from the United States Naval Observatory for folks who
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want to do additional time zones
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* and the 1989 data for Saudi Arabia.
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(Since this code will be treated as "part of the implementation" in some places
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and as "part of the application" in others, there's no good way to name
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functions, such as timegm, that are not part of the proposed ANSI C standard;
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such functions have kept their old, underscore-free names in this update.)
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And the "dysize" function has disappeared; it was present to allow compilation
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of the "date" command on old BSD systems, and a version of "date" is now
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provided in the package. The "date" command is not created when you "make all"
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since it may lack options provided by the version distributed with your
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operating system, or may not interact with the system in the same way the
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native version does.
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Since POSIX frowns on correct leap second handling, the default behavior of
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the "zic" command (in the absence of a "-L" option) has been changed to omit
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leap second information from its output files.
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Here is a recipe for acquiring, building, installing, and testing the
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tz distribution on a GNU/Linux or similar host.
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mkdir tz
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cd tz
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wget --retr-symlinks 'ftp://ftp.iana.org/tz/tz*-latest.tar.gz'
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gzip -dc tzcode-latest.tar.gz | tar -xf -
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gzip -dc tzdata-latest.tar.gz | tar -xf -
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Be sure to read the comments in "Makefile" and make any changes needed
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to make things right for your system, especially if you are using some
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platform other than GNU/Linux. Then run the following commands,
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substituting your desired installation directory for "$HOME/tzdir":
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make TOPDIR=$HOME/tzdir install
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$HOME/tzdir/etc/zdump -v America/Los_Angeles
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To use the new functions, use a "-ltz" option when compiling or linking.
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Historical local time information has been included here to:
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* provide a compendium of data about the history of civil time
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that is useful even if the data are not 100% accurate;
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* give an idea of the variety of local time rules that have
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existed in the past and thus an idea of the variety that may be
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expected in the future;
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* provide a test of the generality of the local time rule description
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system.
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The information in the time zone data files is by no means authoritative;
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the files currently do not even attempt to cover all time stamps before
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1970, and there are undoubtedly errors even for time stamps since 1970.
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If you know that the rules are different from those in a file, by all means
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feel free to change file (and please send the changed version to
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tz@iana.org for use in the future). Europeans take note!
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Thanks to these Timezone Caballeros who've made major contributions to the
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time conversion package: Keith Bostic; Bob Devine; Paul Eggert; Robert Elz;
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Guy Harris; Mark Horton; John Mackin; and Bradley White. Thanks also to
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Michael Bloom, Art Neilson, Stephen Prince, John Sovereign, and Frank Wales
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for testing work, and to Gwillim Law for checking local mean time data.
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None of them are responsible for remaining errors.
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Look in <ftp://ftp.iana.org/tz/releases/>
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for updated versions of these files.
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Please send comments or information to tz@iana.org.
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Postscript: The README above is largely unmodified (aside from details
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of mailing list and ftp archive addresses) from that prepared many years
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ago by Arthur David Olson, to whom the timezone community owes the
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greatest debt of all. Arthur is not currently maintaining this data or
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code (though he remains involved).
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