perl58delta.1

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

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File::Find is now (again) reentrant.  It also has been made
more portable.
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The warnings issued by File::Find now belong to their own category.
You can enable/disable them with \f(CW\*(C`use/no warnings \*(AqFile::Find\*(Aq;\*(C'\fR.
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\&\fIFile::Glob::glob()\fR has been renamed to \fIFile::Glob::bsd_glob()\fR
because the name clashes with the builtin \fIglob()\fR.  The older
name is still available for compatibility, but is deprecated. [561]
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File::Glob now supports \f(CW\*(C`GLOB_LIMIT\*(C'\fR constant to limit the size of
the returned list of filenames.
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IPC::Open3 now allows the use of numeric file descriptors.
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IO::Socket now has an \fIatmark()\fR method, which returns true if the socket
is positioned at the out-of-band mark.  The method is also exportable
as a \fIsockatmark()\fR function.
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IO::Socket::INET failed to open the specified port if the service name
was not known.  It now correctly uses the supplied port number as is. [561]
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IO::Socket::INET has support for the ReusePort option (if your
platform supports it).  The Reuse option now has an alias, ReuseAddr.
For clarity, you may want to prefer ReuseAddr.
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IO::Socket::INET now supports a value of zero for \f(CW\*(C`LocalPort\*(C'\fR
(usually meaning that the operating system will make one up.)
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\&'use lib' now works identically to \f(CW@INC\fR.  Removing directories
with 'no lib' now works.
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Math::BigFloat and Math::BigInt have undergone a full rewrite by Tels.
They are now magnitudes faster, and they support various bignum
libraries such as \s-1GMP\s0 and \s-1PARI\s0 as their backends.
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Math::Complex handles inf, NaN etc., better.
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Net::Ping has been considerably enhanced by Rob Brown: multihoming is
now supported, Win32 functionality is better, there is now time
measuring functionality (optionally high-resolution using
Time::HiRes), and there is now \*(L"external\*(R" protocol which uses
Net::Ping::External module which runs your external ping utility and
parses the output.  A version of Net::Ping::External is available in
\&\s-1CPAN\s0.
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Note that some of the Net::Ping tests are disabled when running
under the Perl distribution since one cannot assume one or more
of the following: enabled echo port at localhost, full Internet
connectivity, or sympathetic firewalls.  You can set the environment
variable PERL_TEST_Net_Ping to \*(L"1\*(R" (one) before running the Perl test
suite to enable all the Net::Ping tests.
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\&\fIPOSIX::sigaction()\fR is now much more flexible and robust.
You can now install coderef handlers, '\s-1DEFAULT\s0', and '\s-1IGNORE\s0'
handlers, installing new handlers was not atomic.
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In Safe, \f(CW%INC\fR is now localised in a Safe compartment so that
use/require work.
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In SDBM_File on dosish platforms, some keys went missing because of
lack of support for files with \*(L"holes\*(R".  A workaround for the problem
has been added.
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In Search::Dict one can now have a pre-processing hook for the
lines being searched.
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The Shell module now has an \s-1OO\s0 interface.
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In Sys::Syslog there is now a failover mechanism that will go
through alternative connection mechanisms until the message
is successfully logged.
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The Test module has been significantly enhanced.
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\&\fITime::Local::timelocal()\fR does not handle fractional seconds anymore.
The rationale is that neither does \fIlocaltime()\fR, and \fItimelocal()\fR and
\&\fIlocaltime()\fR are supposed to be inverses of each other.
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The vars pragma now supports declaring fully qualified variables.
(Something that \f(CW\*(C`our()\*(C'\fR does not and will not support.)
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The \f(CW\*(C`utf8::\*(C'\fR name space (as in the pragma) provides various
Perl-callable functions to provide low level access to Perl's
internal Unicode representation.  At the moment only \fIlength()\fR
has been implemented.
.SH "Utility Changes"
.IX Header "Utility Changes"
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Emacs perl mode (emacs/cperl\-mode.el) has been updated to version
4.31.
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\&\fIemacs/e2ctags.pl\fR is now much faster.
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\&\f(CW\*(C`enc2xs\*(C'\fR is a tool for people adding their own encodings to the
Encode module.
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\&\f(CW\*(C`h2ph\*(C'\fR now supports C trigraphs.
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\&\f(CW\*(C`h2xs\*(C'\fR now produces a template \s-1README\s0.
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\&\f(CW\*(C`h2xs\*(C'\fR now uses \f(CW\*(C`Devel::PPPort\*(C'\fR for better portability between
different versions of Perl.
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\&\f(CW\*(C`h2xs\*(C'\fR uses the new ExtUtils::Constant module
which will affect newly created extensions that define constants.
Since the new code is more correct (if you have two constants where the
first one is a prefix of the second one, the first constant \fBnever\fR
got defined), less lossy (it uses integers for integer constant,
as opposed to the old code that used floating point numbers even for
integer constants), and slightly faster, you might want to consider
regenerating your extension code (the new scheme makes regenerating
easy).  h2xs now also supports C trigraphs.
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\&\f(CW\*(C`libnetcfg\*(C'\fR has been added to configure libnet.
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\&\f(CW\*(C`perlbug\*(C'\fR is now much more robust.  It also sends the bug report to
perl.org, not perl.com.
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\&\f(CW\*(C`perlcc\*(C'\fR has been rewritten and its user interface (that is,
command line) is much more like that of the \s-1UNIX\s0 C compiler, cc.
(The perlbc tools has been removed.  Use \f(CW\*(C`perlcc \-B\*(C'\fR instead.)
\&\fBNote that perlcc is still considered very experimental and
unsupported.\fR [561]
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\&\f(CW\*(C`perlivp\*(C'\fR is a new Installation Verification Procedure utility
for running any time after installing Perl.
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\&\f(CW\*(C`piconv\*(C'\fR is an implementation of the character conversion utility
\&\f(CW\*(C`iconv\*(C'\fR, demonstrating the new Encode module.
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\&\f(CW\*(C`pod2html\*(C'\fR now allows specifying a cache directory.
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\&\f(CW\*(C`pod2html\*(C'\fR now produces \s-1XHTML\s0 1.0.
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\&\f(CW\*(C`pod2html\*(C'\fR now understands \s-1POD\s0 written using different line endings
(PC-like \s-1CRLF\s0 versus UNIX-like \s-1LF\s0 versus MacClassic-like \s-1CR\s0).
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\&\f(CW\*(C`s2p\*(C'\fR has been completely rewritten in Perl.  (It is in fact a full
implementation of sed in Perl: you can use the sed functionality by
using the \f(CW\*(C`psed\*(C'\fR utility.)
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\&\f(CW\*(C`xsubpp\*(C'\fR now understands \s-1POD\s0 documentation embedded in the *.xs
files. [561]
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\&\f(CW\*(C`xsubpp\*(C'\fR now supports the \s-1OUT\s0 keyword.
.SH "New Documentation"
.IX Header "New Documentation"
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perl56delta details the changes between the 5.005 release and the
5.6.0 release.
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perlclib documents the internal replacements for standard C library
functions.  (Interesting only for extension writers and Perl core
hackers.) [561+]
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perldebtut is a Perl debugging tutorial. [561+]
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perlebcdic contains considerations for running Perl on \s-1EBCDIC\s0
platforms. [561+]
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perlintro is a gentle introduction to Perl.
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perliol documents the internals of PerlIO with layers.
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perlmodstyle is a style guide for writing modules.
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perlnewmod tells about writing and submitting a new module. [561+]
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perlpacktut is a \fIpack()\fR tutorial.
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perlpod has been rewritten to be clearer and to record the best
practices gathered over the years.
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perlpodspec is a more formal specification of the pod format,
mainly of interest for writers of pod applications, not to
people writing in pod.
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perlretut is a regular expression tutorial. [561+]
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perlrequick is a regular expressions quick-start guide.
Yes, much quicker than perlretut. [561]
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perltodo has been updated.
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perltootc has been renamed as perltooc (to not to conflict
with perltoot in filesystems restricted to \*(L"8.3\*(R" names).
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perluniintro is an introduction to using Unicode in Perl.
(perlunicode is more of a detailed reference and background
information)
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perlutil explains the command line utilities packaged with the Perl
distribution. [561+]
.PP
The following platform-specific documents are available before
the installation as \s-1README\s0.\fIplatform\fR, and after the installation
as perl\fIplatform\fR:
.PP
.Vb 5
\&    perlaix perlamiga perlapollo perlbeos perlbs2000
\&    perlce perlcygwin perldgux perldos perlepoc perlfreebsd perlhpux
\&    perlhurd perlirix perlmachten perlmacos perlmint perlmpeix
\&    perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris
\&    perltru64 perluts perlvmesa perlvms perlvos perlwin32
.Ve
.PP
These documents usually detail one or more of the following subjects:
configuring, building, testing, installing, and sometimes also using
Perl on the said platform.
.PP
Eastern Asian Perl users are now welcomed in their own languages:
\&\s-1README\s0.jp (Japanese), \s-1README\s0.ko (Korean), \s-1README\s0.cn (simplified
Chinese) and \s-1README\s0.tw (traditional Chinese), which are written in
normal pod but encoded in EUC-JP, EUC-KR, EUC-CN and Big5.  These
will get installed as
.PP
.Vb 1
\&   perljp perlko perlcn perltw
.Ve
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The documentation for the POSIX-BC platform is called \*(L"\s-1BS2000\s0\*(R", to avoid
confusion with the Perl \s-1POSIX\s0 module.
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The documentation for the WinCE platform is called perlce (\s-1README\s0.ce
in the source code kit), to avoid confusion with the perlwin32
documentation on 8.3\-restricted filesystems.
.SH "Performance Enhancements"
.IX Header "Performance Enhancements"
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\&\fImap()\fR could get pathologically slow when the result list it generates
is larger than the source list.  The performance has been improved for
common scenarios. [561]
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\&\fIsort()\fR is also fully reentrant, in the sense that the sort function
can itself call \fIsort()\fR.  This did not work reliably in previous
releases. [561]
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\&\fIsort()\fR has been changed to use primarily mergesort internally as
opposed to the earlier quicksort.  For very small lists this may
result in slightly slower sorting times, but in general the speedup
should be at least 20%.  Additional bonuses are that the worst case
behaviour of \fIsort()\fR is now better (in computer science terms it now
runs in time O(N log N), as opposed to quicksort's Theta(N**2)
worst-case run time behaviour), and that \fIsort()\fR is now stable
(meaning that elements with identical keys will stay ordered as they
were before the sort).  See the \f(CW\*(C`sort\*(C'\fR pragma for information.
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The story in more detail: suppose you want to serve yourself a little
slice of Pi.
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\&    @digits = ( 3,1,4,1,5,9 );
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A numerical sort of the digits will yield (1,1,3,4,5,9), as expected.
Which \f(CW1\fR comes first is hard to know, since one \f(CW1\fR looks pretty
much like any other.  You can regard this as totally trivial,
or somewhat profound.  However, if you just want to sort the even
digits ahead of the odd ones, then what will
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\&    sort { ($a % 2) <=> ($b % 2) } @digits;
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yield?  The only even digit, \f(CW4\fR, will come first.  But how about
the odd numbers, which all compare equal?  With the quicksort algorithm
used to implement Perl 5.6 and earlier, the order of ties is left up
to the sort.  So, as you add more and more digits of Pi, the order
in which the sorted even and odd digits appear will change.
and, for sufficiently large slices of Pi, the quicksort algorithm
in Perl 5.8 won't return the same results even if reinvoked with the
same input.  The justification for this rests with quicksort's
worst case behavior.  If you run
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\&   sort { $a <=> $b } ( 1 .. $N , 1 .. $N );
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(something you might approximate if you wanted to merge two sorted
arrays using sort), doubling \f(CW$N\fR doesn't just double the quicksort time,
it \fIquadruples\fR it.  Quicksort has a worst case run time that can
grow like N**2, so-called \fIquadratic\fR behaviour, and it can happen
on patterns that may well arise in normal use.  You won't notice this
for small arrays, but you \fIwill\fR notice it with larger arrays,
and you may not live long enough for the sort to complete on arrays
of a million elements.  So the 5.8 quicksort scrambles large arrays
before sorting them, as a statistical defence against quadratic behaviour.
But that means if you sort the same large array twice, ties m