perl5005delta.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.

value in exception traps.  This makes it possible to propagate
exception objects.  This is an undocumented \fBexperimental\fR feature.
.Sh "Re-blessing in \s-1\fIDESTROY\s0()\fP supported for chaining \s-1\fIDESTROY\s0()\fP methods"
.IX Subsection "Re-blessing in DESTROY() supported for chaining DESTROY() methods"
See \*(L"Destructors\*(R" in perlobj.
.ie n .Sh "All ""printf"" format conversions are handled internally"
.el .Sh "All \f(CWprintf\fP format conversions are handled internally"
.IX Subsection "All printf format conversions are handled internally"
See \*(L"printf\*(R" in perlfunc.
.ie n .Sh "New ""INIT"" keyword"
.el .Sh "New \f(CWINIT\fP keyword"
.IX Subsection "New INIT keyword"
\&\f(CW\*(C`INIT\*(C'\fR subs are like \f(CW\*(C`BEGIN\*(C'\fR and \f(CW\*(C`END\*(C'\fR, but they get run just before
the perl runtime begins execution.  e.g., the Perl Compiler makes use of
\&\f(CW\*(C`INIT\*(C'\fR blocks to initialize and resolve pointers to XSUBs.
.ie n .Sh "New ""lock"" keyword"
.el .Sh "New \f(CWlock\fP keyword"
.IX Subsection "New lock keyword"
The \f(CW\*(C`lock\*(C'\fR keyword is the fundamental synchronization primitive
in threaded perl.  When threads are not enabled, it is currently a noop.
.PP
To minimize impact on source compatibility this keyword is \*(L"weak\*(R", i.e., any
user-defined subroutine of the same name overrides it, unless a \f(CW\*(C`use Thread\*(C'\fR
has been seen.
.ie n .Sh "New ""qr//"" operator"
.el .Sh "New \f(CWqr//\fP operator"
.IX Subsection "New qr// operator"
The \f(CW\*(C`qr//\*(C'\fR operator, which is syntactically similar to the other quote-like
operators, is used to create precompiled regular expressions.  This compiled
form can now be explicitly passed around in variables, and interpolated in
other regular expressions.  See perlop.
.ie n .Sh """our"" is now a reserved word"
.el .Sh "\f(CWour\fP is now a reserved word"
.IX Subsection "our is now a reserved word"
Calling a subroutine with the name \f(CW\*(C`our\*(C'\fR will now provoke a warning when
using the \f(CW\*(C`\-w\*(C'\fR switch.
.Sh "Tied arrays are now fully supported"
.IX Subsection "Tied arrays are now fully supported"
See Tie::Array.
.Sh "Tied handles support is better"
.IX Subsection "Tied handles support is better"
Several missing hooks have been added.  There is also a new base class for
\&\s-1TIEARRAY\s0 implementations.  See Tie::Array.
.Sh "4th argument to substr"
.IX Subsection "4th argument to substr"
\&\fIsubstr()\fR can now both return and replace in one operation.  The optional
4th argument is the replacement string.  See \*(L"substr\*(R" in perlfunc.
.Sh "Negative \s-1LENGTH\s0 argument to splice"
.IX Subsection "Negative LENGTH argument to splice"
\&\fIsplice()\fR with a negative \s-1LENGTH\s0 argument now work similar to what the
\&\s-1LENGTH\s0 did for \fIsubstr()\fR.  Previously a negative \s-1LENGTH\s0 was treated as
0.  See \*(L"splice\*(R" in perlfunc.
.Sh "Magic lvalues are now more magical"
.IX Subsection "Magic lvalues are now more magical"
When you say something like \f(CW\*(C`substr($x, 5) = "hi"\*(C'\fR, the scalar returned
by \fIsubstr()\fR is special, in that any modifications to it affect \f(CW$x\fR.
(This is called a 'magic lvalue' because an 'lvalue' is something on
the left side of an assignment.)  Normally, this is exactly what you
would expect to happen, but Perl uses the same magic if you use \fIsubstr()\fR,
\&\fIpos()\fR, or \fIvec()\fR in a context where they might be modified, like taking
a reference with \f(CW\*(C`\e\*(C'\fR or as an argument to a sub that modifies \f(CW@_\fR.
In previous versions, this 'magic' only went one way, but now changes
to the scalar the magic refers to ($x in the above example) affect the
magic lvalue too. For instance, this code now acts differently:
.PP
.Vb 6
\&    $x = "hello";
\&    sub printit {
\&        $x = "g\*(Aqbye";
\&        print $_[0], "\en";
\&    }
\&    printit(substr($x, 0, 5));
.Ve
.PP
In previous versions, this would print \*(L"hello\*(R", but it now prints \*(L"g'bye\*(R".
.Sh "<> now reads in records"
.IX Subsection "<> now reads in records"
If \f(CW$/\fR is a reference to an integer, or a scalar that holds an integer,
<> will read in records instead of lines. For more info, see
\&\*(L"$/\*(R" in perlvar.
.SH "Supported Platforms"
.IX Header "Supported Platforms"
Configure has many incremental improvements.  Site-wide policy for building
perl can now be made persistent, via Policy.sh.  Configure also records
the command-line arguments used in \fIconfig.sh\fR.
.Sh "New Platforms"
.IX Subsection "New Platforms"
BeOS is now supported.  See \fI\s-1README\s0.beos\fR.
.PP
\&\s-1DOS\s0 is now supported under the \s-1DJGPP\s0 tools.  See \fI\s-1README\s0.dos\fR (installed 
as perldos on some systems).
.PP
MiNT is now supported.  See \fI\s-1README\s0.mint\fR.
.PP
MPE/iX is now supported.  See \fI\s-1README\s0.mpeix\fR.
.PP
\&\s-1MVS\s0 (aka \s-1OS390\s0, aka Open Edition) is now supported.  See \fI\s-1README\s0.os390\fR 
(installed as perlos390 on some systems).
.PP
Stratus \s-1VOS\s0 is now supported.  See \fI\s-1README\s0.vos\fR.
.Sh "Changes in existing support"
.IX Subsection "Changes in existing support"
Win32 support has been vastly enhanced.  Support for Perl Object, a \*(C+
encapsulation of Perl.  \s-1GCC\s0 and \s-1EGCS\s0 are now supported on Win32.
See \fI\s-1README\s0.win32\fR, aka perlwin32.
.PP
\&\s-1VMS\s0 configuration system has been rewritten.  See \fI\s-1README\s0.vms\fR (installed 
as README_vms on some systems).
.PP
The hints files for most Unix platforms have seen incremental improvements.
.SH "Modules and Pragmata"
.IX Header "Modules and Pragmata"
.Sh "New Modules"
.IX Subsection "New Modules"
.IP "B" 4
.IX Item "B"
Perl compiler and tools.  See B.
.IP "Data::Dumper" 4
.IX Item "Data::Dumper"
A module to pretty print Perl data.  See Data::Dumper.
.IP "Dumpvalue" 4
.IX Item "Dumpvalue"
A module to dump perl values to the screen. See Dumpvalue.
.IP "Errno" 4
.IX Item "Errno"
A module to look up errors more conveniently.  See Errno.
.IP "File::Spec" 4
.IX Item "File::Spec"
A portable \s-1API\s0 for file operations.
.IP "ExtUtils::Installed" 4
.IX Item "ExtUtils::Installed"
Query and manage installed modules.
.IP "ExtUtils::Packlist" 4
.IX Item "ExtUtils::Packlist"
Manipulate .packlist files.
.IP "Fatal" 4
.IX Item "Fatal"
Make functions/builtins succeed or die.
.IP "IPC::SysV" 4
.IX Item "IPC::SysV"
Constants and other support infrastructure for System V \s-1IPC\s0 operations
in perl.
.IP "Test" 4
.IX Item "Test"
A framework for writing test suites.
.IP "Tie::Array" 4
.IX Item "Tie::Array"
Base class for tied arrays.
.IP "Tie::Handle" 4
.IX Item "Tie::Handle"
Base class for tied handles.
.IP "Thread" 4
.IX Item "Thread"
Perl thread creation, manipulation, and support.
.IP "attrs" 4
.IX Item "attrs"
Set subroutine attributes.
.IP "fields" 4
.IX Item "fields"
Compile-time class fields.
.IP "re" 4
.IX Item "re"
Various pragmata to control behavior of regular expressions.
.Sh "Changes in existing modules"
.IX Subsection "Changes in existing modules"
.IP "Benchmark" 4
.IX Item "Benchmark"
You can now run tests for \fIx\fR seconds instead of guessing the right
number of tests to run.
.Sp
Keeps better time.
.IP "Carp" 4
.IX Item "Carp"
Carp has a new function \fIcluck()\fR. \fIcluck()\fR warns, like \fIcarp()\fR, but also adds
a stack backtrace to the error message, like \fIconfess()\fR.
.IP "\s-1CGI\s0" 4
.IX Item "CGI"
\&\s-1CGI\s0 has been updated to version 2.42.
.IP "Fcntl" 4
.IX Item "Fcntl"
More Fcntl constants added: F_SETLK64, F_SETLKW64, O_LARGEFILE for
large (more than 4G) file access (the 64\-bit support is not yet
working, though, so no need to get overly excited), Free/Net/OpenBSD
locking behaviour flags F_FLOCK, F_POSIX, Linux F_SHLCK, and
O_ACCMODE: the mask of O_RDONLY, O_WRONLY, and O_RDWR.
.IP "Math::Complex" 4
.IX Item "Math::Complex"
The accessors methods Re, Im, arg, abs, rho, theta, methods can
($z\->\fIRe()\fR) now also act as mutators ($z\->\fIRe\fR\|(3)).
.IP "Math::Trig" 4
.IX Item "Math::Trig"
A little bit of radial trigonometry (cylindrical and spherical) added,
for example the great circle distance.
.IP "\s-1POSIX\s0" 4
.IX Item "POSIX"
\&\s-1POSIX\s0 now has its own platform-specific hints files.
.IP "DB_File" 4
.IX Item "DB_File"
DB_File supports version 2.x of Berkeley \s-1DB\s0.  See \f(CW\*(C`ext/DB_File/Changes\*(C'\fR.
.IP "MakeMaker" 4
.IX Item "MakeMaker"
MakeMaker now supports writing empty makefiles, provides a way to
specify that site \fIumask()\fR policy should be honored.  There is also
better support for manipulation of .packlist files, and getting
information about installed modules.
.Sp
Extensions that have both architecture-dependent and
architecture-independent files are now always installed completely in
the architecture-dependent locations.  Previously, the shareable parts
were shared both across architectures and across perl versions and were
therefore liable to be overwritten with newer versions that might have
subtle incompatibilities.
.IP "\s-1CPAN\s0" 4
.IX Item "CPAN"
See perlmodinstall and \s-1CPAN\s0.
.IP "Cwd" 4
.IX Item "Cwd"
Cwd::cwd is faster on most platforms.
.SH "Utility Changes"
.IX Header "Utility Changes"
\&\f(CW\*(C`h2ph\*(C'\fR and related utilities have been vastly overhauled.
.PP
\&\f(CW\*(C`perlcc\*(C'\fR, a new experimental front end for the compiler is available.
.PP
The crude \s-1GNU\s0 \f(CW\*(C`configure\*(C'\fR emulator is now called \f(CW\*(C`configure.gnu\*(C'\fR to
avoid trampling on \f(CW\*(C`Configure\*(C'\fR under case-insensitive filesystems.
.PP
\&\f(CW\*(C`perldoc\*(C'\fR used to be rather slow.  The slower features are now optional.
In particular, case-insensitive searches need the \f(CW\*(C`\-i\*(C'\fR switch, and
recursive searches need \f(CW\*(C`\-r\*(C'\fR.  You can set these switches in the
\&\f(CW\*(C`PERLDOC\*(C'\fR environment variable to get the old behavior.
.SH "Documentation Changes"
.IX Header "Documentation Changes"
Config.pm now has a glossary of variables.
.PP
\&\fIPorting/patching.pod\fR has detailed instructions on how to create and
submit patches for perl.
.PP
perlport specifies guidelines on how to write portably.
.PP
perlmodinstall describes how to fetch and install modules from \f(CW\*(C`CPAN\*(C'\fR
sites.
.PP
Some more Perl traps are documented now.  See perltrap.
.PP
perlopentut gives a tutorial on using \fIopen()\fR.
.PP
perlreftut gives a tutorial on references.
.PP
perlthrtut gives a tutorial on threads.
.SH "New Diagnostics"
.IX Header "New Diagnostics"
.IP "Ambiguous call resolved as CORE::%s(), qualify as such or use &" 4
.IX Item "Ambiguous call resolved as CORE::%s(), qualify as such or use &"
(W) A subroutine you have declared has the same name as a Perl keyword,
and you have used the name without qualification for calling one or the