perl571delta.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.

.IP "\(bu" 4
If you are on \s-1IRIX\s0 or Tru64 platforms, new profiling/debugging options
have been added, see perlhack for more information about pixie and
Third Degree.
.Sh "New Or Improved Platforms"
.IX Subsection "New Or Improved Platforms"
For the list of platforms known to support Perl,
see \*(L"Supported Platforms\*(R" in perlport.
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\&\s-1AIX\s0 dynamic loading should be now better supported.
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After a long pause, AmigaOS has been verified to be happy with Perl.
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\&\s-1EBCDIC\s0 platforms (z/OS, also known as \s-1OS/390\s0, POSIX-BC, and \s-1VM/ESA\s0)
have been regained.  Many test suite tests still fail and the
co-existence of Unicode and \s-1EBCDIC\s0 isn't quite settled, but the
situation is much better than with Perl 5.6.  See perlos390,
perlbs2000 (for POSIX-BC), and perlvmesa for more information.
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Building perl with \-Duseithreads or \-Duse5005threads now works under
HP-UX 10.20 (previously it only worked under 10.30 or later). You will
need a thread library package installed. See \s-1README\s0.hpux.
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Mac \s-1OS\s0 Classic (MacPerl has of course been available since
perl 5.004 but now the source code bases of standard Perl
and MacPerl have been synchronised)
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\&\s-1NCR\s0 MP-RAS is now supported.
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NonStop-UX is now supported.
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Amdahl \s-1UTS\s0 is now supported.
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z/OS (formerly known as \s-1OS/390\s0, formerly known as \s-1MVS\s0 \s-1OE\s0) has now
support for dynamic loading.  This is not selected by default,
however, you must specify \-Dusedl in the arguments of Configure.
.Sh "Generic Improvements"
.IX Subsection "Generic Improvements"
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Configure no longer includes the \s-1DBM\s0 libraries (dbm, gdbm, db, ndbm)
when building the Perl binary.  The only exception to this is SunOS 4.x,
which needs them.
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Some new Configure symbols, useful for extension writers:
.RS 4
.IP "d_cmsghdr" 8
.IX Item "d_cmsghdr"
For struct cmsghdr.
.IP "d_fcntl_can_lock" 8
.IX Item "d_fcntl_can_lock"
Whether \fIfcntl()\fR can be used for file locking.
.IP "d_fsync" 8
.IX Item "d_fsync"
.PD 0
.IP "d_getitimer" 8
.IX Item "d_getitimer"
.IP "d_getpagsz" 8
.IX Item "d_getpagsz"
.PD
For \fIgetpagesize()\fR, though you should prefer POSIX::sysconf(_SC_PAGE_SIZE))
.IP "d_msghdr_s" 8
.IX Item "d_msghdr_s"
For struct msghdr.
.IP "need_va_copy" 8
.IX Item "need_va_copy"
Whether one needs to use \fIPerl_va_copy()\fR to copy varargs.
.IP "d_readv" 8
.IX Item "d_readv"
.PD 0
.IP "d_recvmsg" 8
.IX Item "d_recvmsg"
.IP "d_sendmsg" 8
.IX Item "d_sendmsg"
.IP "sig_size" 8
.IX Item "sig_size"
.PD
The number of elements in an array needed to hold all the available signals.
.IP "d_sockatmark" 8
.IX Item "d_sockatmark"
.PD 0
.IP "d_strtoq" 8
.IX Item "d_strtoq"
.IP "d_u32align" 8
.IX Item "d_u32align"
.PD
Whether one needs to access character data aligned by U32 sized pointers.
.IP "d_ualarm" 8
.IX Item "d_ualarm"
.PD 0
.IP "d_usleep" 8
.IX Item "d_usleep"
.RE
.RS 4
.RE
.IP "\(bu" 4
.PD
Removed Configure symbols: the \s-1PDP\-11\s0 memory model settings: huge,
large, medium, models.
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\&\s-1SOCKS\s0 support is now much more robust.
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If your file system supports symbolic links you can build Perl outside
of the source directory by
.Sp
.Vb 3
\&        mkdir perl/build/directory
\&        cd perl/build/directory
\&        sh /path/to/perl/source/Configure \-Dmksymlinks ...
.Ve
.Sp
This will create in perl/build/directory a tree of symbolic links
pointing to files in /path/to/perl/source.  The original files are left
unaffected.  After Configure has finished you can just say
.Sp
.Vb 1
\&        make all test
.Ve
.Sp
and Perl will be built and tested, all in perl/build/directory.
.SH "Selected Bug Fixes"
.IX Header "Selected Bug Fixes"
Numerous memory leaks and uninitialized memory accesses have been hunted down.
Most importantly anonymous subs used to leak quite a bit.
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chop(@list) in list context returned the characters chopped in
reverse order.  This has been reversed to be in the right order.
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The order of DESTROYs has been made more predictable.
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\&\fImkdir()\fR now ignores trailing slashes in the directory name,
as mandated by \s-1POSIX\s0.
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Attributes (like :shared) didn't work with \fIour()\fR.
.IP "\(bu" 4
The \s-1PERL5OPT\s0 environment variable (for passing command line arguments
to Perl) didn't work for more than a single group of options.
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The tainting behaviour of \fIsprintf()\fR has been rationalized.  It does
not taint the result of floating point formats anymore, making the
behaviour consistent with that of string interpolation.
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All but the first argument of the \s-1IO\s0 \fIsyswrite()\fR method are now optional.
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Tie::ARRAY \s-1SPLICE\s0 method was broken.
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\&\fIvec()\fR now tries to work with characters <= 255 when possible, but it leaves
higher character values in place.  In that case, if \fIvec()\fR was used to modify
the string, it is no longer considered to be utf8\-encoded.
.Sh "Platform Specific Changes and Fixes"
.IX Subsection "Platform Specific Changes and Fixes"
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Linux previously had problems related to sockaddrlen when using
\&\fIaccept()\fR, \fIrevcfrom()\fR (in Perl: \fIrecv()\fR), \fIgetpeername()\fR, and \fIgetsockname()\fR.
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Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
.IP "\(bu" 4
Windows
.RS 4
.IP "\(bu" 8
Borland \*(C+ v5.5 is now a supported compiler that can build Perl.
However, the generated binaries continue to be incompatible with those
generated by the other supported compilers (\s-1GCC\s0 and Visual \*(C+).
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\&\fIWin32::GetCwd()\fR correctly returns C:\e instead of C: when at the drive root.
Other bugs in \fIchdir()\fR and \fICwd::cwd()\fR have also been fixed.
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Duping socket handles with open(F, \*(L">&MYSOCK\*(R") now works under Windows 9x.
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\&\s-1HTML\s0 files will be installed in c:\eperl\ehtml instead of c:\eperl\elib\epod\ehtml
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The makefiles now provide a single switch to bulk-enable all the features
enabled in ActiveState ActivePerl (a popular binary distribution).
.RE
.RS 4
.RE
.SH "New or Changed Diagnostics"
.IX Header "New or Changed Diagnostics"
Two new debugging options have been added: if you have compiled your
Perl with debugging, you can use the \-DT and \-DR options to trace
tokenising and to add reference counts to displaying variables,
respectively.
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If an attempt to use a (non-blessed) reference as an array index
is made, a warning is given.
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\&\f(CW\*(C`push @a;\*(C'\fR and \f(CW\*(C`unshift @a;\*(C'\fR (with no values to push or unshift)
now give a warning.  This may be a problem for generated and eval'ed
code.
.SH "Changed Internals"
.IX Header "Changed Internals"
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Some new APIs: \fIptr_table_clear()\fR, \fIptr_table_free()\fR, \fIsv_setref_uv()\fR.
For the full list of the available APIs see perlapi.
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dTHR and djSP have been obsoleted; the former removed (because it's
a no-op) and the latter replaced with dSP.
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Perl now uses system malloc instead of Perl malloc on all 64\-bit
platforms, and even in some not\-always\-64\-bit platforms like \s-1AIX\s0,
\&\s-1IRIX\s0, and Solaris.  This change breaks backward compatibility but
Perl's malloc has problems with large address spaces and also the
speed of vendors' malloc is generally better in large address space
machines (Perl's malloc is mostly tuned for space).
.SH "New Tests"
.IX Header "New Tests"
Many new tests have been added.  The most notable is probably the
lib/1_compile: it is very notable because running it takes quite a
long time \*(-- it test compiles all the Perl modules in the distribution.
Please be patient.
.SH "Known Problems"
.IX Header "Known Problems"
Note that unlike other sections in this document (which describe
changes since 5.7.0) this section is cumulative containing known
problems for all the 5.7 releases.
.Sh "\s-1AIX\s0 vac 5.0.0.0 May Produce Buggy Code For Perl"
.IX Subsection "AIX vac 5.0.0.0 May Produce Buggy Code For Perl"
The \s-1AIX\s0 C compiler vac version 5.0.0.0 may produce buggy code,
resulting in few random tests failing, but when the failing tests
are run by hand, they succeed.  We suggest upgrading to at least
vac version 5.0.1.0, that has been known to compile Perl correctly.
\&\*(L"lslpp \-L|grep vac.C\*(R" will tell you the vac version.
.Sh "lib/ftmp\-security tests warn 'system possibly insecure'"
.IX Subsection "lib/ftmp-security tests warn 'system possibly insecure'"
Don't panic.  Read \s-1INSTALL\s0 'make test' section instead.
.Sh "lib/io_multihomed Fails In LP64\-Configured HP-UX"
.IX Subsection "lib/io_multihomed Fails In LP64-Configured HP-UX"
The lib/io_multihomed test may hang in HP-UX if Perl has been
configured to be 64\-bit. Because other 64\-bit platforms do not hang in
this test, HP-UX is suspect. All other tests pass in 64\-bit HP-UX. The
test attempts to create and connect to \*(L"multihomed\*(R" sockets (sockets
which have multiple \s-1IP\s0 addresses).
.Sh "Test lib/posix Subtest 9 Fails In LP64\-Configured HP-UX"
.IX Subsection "Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX"
If perl is configured with \-Duse64bitall, the successful result of the
subtest 10 of lib/posix may arrive before the successful result of the
subtest 9, which confuses the test harness so much that it thinks the
subtest 9 failed.
.Sh "lib/b test 19"
.IX Subsection "lib/b test 19"
The test fails on various platforms (\s-1PA64\s0 and \s-1IA64\s0 are known), but the
exact cause is still being investigated.
.Sh "Linux With Sfio Fails op/misc Test 48"
.IX Subsection "Linux With Sfio Fails op/misc Test 48"
No known fix.
.Sh "sigaction test 13 in \s-1VMS\s0"
.IX Subsection "sigaction test 13 in VMS"
The test is known to fail; whether it's because of \s-1VMS\s0 of because
of faulty test is not known.
.Sh "sprintf tests 129 and 130"
.IX Subsection "sprintf tests 129 and 130"
The op/sprintf tests 129 and 130 are known to fail on some platforms.
Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
The failing platforms do not comply with the \s-1ANSI\s0 C Standard, line
19ff on page 134 of \s-1ANSI\s0 X3.159 1989 to be exact.  (They produce
something else than \*(L"1\*(R" and \*(L"\-1\*(R" when formatting 0.6 and \-0.6 using
the printf format \*(L"%.0f\*(R", most often they produce \*(L"0\*(R" and \*(L"\-0\*(R".)
.Sh "Failure of Thread tests"
.IX Subsection "Failure of Thread tests"
The subtests 19 and 20 of lib/thr5005.t test are known to fail due to
fundamental problems in the 5.005 threading implementation. These are
not new failures\*(--Perl 5.005_0x has the same bugs, but didn't have
these tests. (Note that support for 5.005\-style threading remains
experimental.)
.Sh "Localising a Tied Variable Leaks Memory"
.IX Subsection "Localising a Tied Variable Leaks Memory"
.Vb 2
\&    use Tie::Hash;
\&    tie my %tie_hash => \*(AqTie::StdHash\*(Aq;
\&
\&    ...
\&
\&    local($tie_hash{Foo}) = 1; # leaks
.Ve
.PP
Code like the above is known to leak memory every time the \fIlocal()\fR
is executed.
.Sh "Self-tying of Arrays and Hashes Is Forbidden"
.IX Subsection "Self-tying of Arrays and Hashes Is Forbidden"
Self-tying of arrays and hashes is broken in rather deep and
hard-to-fix ways.  As a stop-gap measure to avoid people from getting
frustrated at the mysterious results (core dumps, most often) it is
for now forbidden (you will get a fatal error even from an attempt).
.Sh "Building Extensions Can Fail Because Of Largefiles"
.IX Subsection "Building Extensions Can Fail Because Of Largefiles"
Some extensions like mod_perl are known to have issues with
`largefiles', a change brought by Perl 5.6.0 in which file offsets
default to 64 bits wide, where supported.  Modules may fail to compile
at all or compile and work incorrectly.  Currently there is no good
solution for the problem, but Configure now provides appropriate
non-largefile ccflags, ldflags, libswanted, and libs in the \f(CW%Config\fR
hash (e.g., \f(CW$Config\fR{ccflags_nolargefiles}) so the extensions that are
having problems can try configuring themselves without the
largefileness.  This is admittedly not a clean solution, and the
solution may not even work at all.  One potential failure is whether
one can (or, if one can, whether it's a good idea) link together at
all binaries with different ideas about file offsets, all this is
platform-dependent.
.Sh "The Compiler Suite Is Still Experimental"
.IX Subsection "The Compiler Suite Is Still Experimental"
The compiler suite is slowly getting better but is nowhere near
working order yet.
.SH "Reporting Bugs"
.IX Header "Reporting Bugs"
If you find what you think is a bug, you might check the articles
recently posted to the comp.lang.perl.misc newsgroup and the perl
bug database at http://bugs.perl.org/  There may also be
information at http://www.perl.com/perl/ , the Perl Home Page.
.PP
If you believe you have an unreported bug, please run the \fBperlbug\fR
program included with your release.  Be sure to trim your bug down
to a tiny but sufficient test case.  Your bug report, along with the
output of \f(CW\*(C`perl \-V\*(C'\fR, will be sent off to [e-mail] to be
analysed by the Perl porting team.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
The \fIChanges\fR file for exhaustive details on what changed.
.PP
The \fI\s-1INSTALL\s0\fR file for how to build Perl.
.PP
The \fI\s-1README\s0\fR file for general stuff.
.PP
The \fIArtistic\fR and \fICopying\fR files for copyright information.
.SH "HISTORY"
.IX Header "HISTORY"
Written by Jarkko Hietaniemi <\[e-mail]\fR>, with many contributions
from The Perl Porters and Perl Users submitting feedback and patches.
.PP
Send omissions or corrections to <\[e-mail]\fR>.