perl.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.

\&    perlhist            Perl history records
\&    perldelta           Perl changes since previous version
\&    perl595delta        Perl changes in version 5.9.5
\&    perl594delta        Perl changes in version 5.9.4
\&    perl593delta        Perl changes in version 5.9.3
\&    perl592delta        Perl changes in version 5.9.2
\&    perl591delta        Perl changes in version 5.9.1
\&    perl590delta        Perl changes in version 5.9.0
\&    perl588delta        Perl changes in version 5.8.8
\&    perl587delta        Perl changes in version 5.8.7
\&    perl586delta        Perl changes in version 5.8.6
\&    perl585delta        Perl changes in version 5.8.5
\&    perl584delta        Perl changes in version 5.8.4
\&    perl583delta        Perl changes in version 5.8.3
\&    perl582delta        Perl changes in version 5.8.2
\&    perl581delta        Perl changes in version 5.8.1
\&    perl58delta         Perl changes in version 5.8.0
\&    perl573delta        Perl changes in version 5.7.3
\&    perl572delta        Perl changes in version 5.7.2
\&    perl571delta        Perl changes in version 5.7.1
\&    perl570delta        Perl changes in version 5.7.0
\&    perl561delta        Perl changes in version 5.6.1
\&    perl56delta         Perl changes in version 5.6
\&    perl5005delta       Perl changes in version 5.005
\&    perl5004delta       Perl changes in version 5.004
\&
\&    perlartistic        Perl Artistic License
\&    perlgpl             GNU General Public License
.Ve
.Sh "Language-Specific"
.IX Subsection "Language-Specific"
.Vb 4
\&    perlcn              Perl for Simplified Chinese (in EUC\-CN)
\&    perljp              Perl for Japanese (in EUC\-JP)
\&    perlko              Perl for Korean (in EUC\-KR)
\&    perltw              Perl for Traditional Chinese (in Big5)
.Ve
.Sh "Platform-Specific"
.IX Subsection "Platform-Specific"
.Vb 10
\&    perlaix             Perl notes for AIX
\&    perlamiga           Perl notes for AmigaOS
\&    perlapollo          Perl notes for Apollo DomainOS
\&    perlbeos            Perl notes for BeOS
\&    perlbs2000          Perl notes for POSIX\-BC BS2000
\&    perlce              Perl notes for WinCE
\&    perlcygwin          Perl notes for Cygwin
\&    perldgux            Perl notes for DG/UX
\&    perldos             Perl notes for DOS
\&    perlepoc            Perl notes for EPOC
\&    perlfreebsd         Perl notes for FreeBSD
\&    perlhpux            Perl notes for HP\-UX
\&    perlhurd            Perl notes for Hurd
\&    perlirix            Perl notes for Irix
\&    perllinux           Perl notes for Linux
\&    perlmachten         Perl notes for Power MachTen
\&    perlmacos           Perl notes for Mac OS (Classic)
\&    perlmacosx          Perl notes for Mac OS X
\&    perlmint            Perl notes for MiNT
\&    perlmpeix           Perl notes for MPE/iX
\&    perlnetware         Perl notes for NetWare
\&    perlopenbsd         Perl notes for OpenBSD
\&    perlos2             Perl notes for OS/2
\&    perlos390           Perl notes for OS/390
\&    perlos400           Perl notes for OS/400
\&    perlplan9           Perl notes for Plan 9
\&    perlqnx             Perl notes for QNX
\&    perlriscos          Perl notes for RISC OS
\&    perlsolaris         Perl notes for Solaris
\&    perlsymbian         Perl notes for Symbian
\&    perltru64           Perl notes for Tru64
\&    perluts             Perl notes for UTS
\&    perlvmesa           Perl notes for VM/ESA
\&    perlvms             Perl notes for VMS
\&    perlvos             Perl notes for Stratus VOS
\&    perlwin32           Perl notes for Windows
.Ve
.PP
By default, the manpages listed above are installed in the 
\&\fI/usr/local/man/\fR directory.
.PP
Extensive additional documentation for Perl modules is available.  The
default configuration for perl will place this additional documentation
in the \fI/usr/local/lib/perl5/man\fR directory (or else in the \fIman\fR
subdirectory of the Perl library directory).  Some of this additional
documentation is distributed standard with Perl, but you'll also find
documentation for third-party modules there.
.PP
You should be able to view Perl's documentation with your \fIman\fR\|(1)
program by including the proper directories in the appropriate start-up
files, or in the \s-1MANPATH\s0 environment variable.  To find out where the
configuration has installed the manpages, type:
.PP
.Vb 1
\&    perl \-V:man.dir
.Ve
.PP
If the directories have a common stem, such as \fI/usr/local/man/man1\fR
and \fI/usr/local/man/man3\fR, you need only to add that stem
(\fI/usr/local/man\fR) to your \fIman\fR\|(1) configuration files or your \s-1MANPATH\s0
environment variable.  If they do not share a stem, you'll have to add
both stems.
.PP
If that doesn't work for some reason, you can still use the
supplied \fIperldoc\fR script to view module information.  You might
also look into getting a replacement man program.
.PP
If something strange has gone wrong with your program and you're not
sure where you should look for help, try the \fB\-w\fR switch first.  It
will often point out exactly where the trouble is.
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
Perl is a language optimized for scanning arbitrary
text files, extracting information from those text files, and printing
reports based on that information.  It's also a good language for many
system management tasks.  The language is intended to be practical
(easy to use, efficient, complete) rather than beautiful (tiny,
elegant, minimal).
.PP
Perl combines (in the author's opinion, anyway) some of the best
features of C, \fBsed\fR, \fBawk\fR, and \fBsh\fR, so people familiar with
those languages should have little difficulty with it.  (Language
historians will also note some vestiges of \fBcsh\fR, Pascal, and even
BASIC-PLUS.)  Expression syntax corresponds closely to C
expression syntax.  Unlike most Unix utilities, Perl does not
arbitrarily limit the size of your data\*(--if you've got the memory,
Perl can slurp in your whole file as a single string.  Recursion is of
unlimited depth.  And the tables used by hashes (sometimes called
\&\*(L"associative arrays\*(R") grow as necessary to prevent degraded
performance.  Perl can use sophisticated pattern matching techniques to
scan large amounts of data quickly.  Although optimized for
scanning text, Perl can also deal with binary data, and can make dbm
files look like hashes.  Setuid Perl scripts are safer than C programs
through a dataflow tracing mechanism that prevents many stupid
security holes.
.PP
If you have a problem that would ordinarily use \fBsed\fR or \fBawk\fR or
\&\fBsh\fR, but it exceeds their capabilities or must run a little faster,
and you don't want to write the silly thing in C, then Perl may be for
you.  There are also translators to turn your \fBsed\fR and \fBawk\fR
scripts into Perl scripts.
.PP
But wait, there's more...
.PP
Begun in 1993 (see perlhist), Perl version 5 is nearly a complete
rewrite that provides the following additional benefits:
.IP "\(bu" 4
modularity and reusability using innumerable modules
.Sp
Described in perlmod, perlmodlib, and perlmodinstall.
.IP "\(bu" 4
embeddable and extensible
.Sp
Described in perlembed, perlxstut, perlxs, perlcall,
perlguts, and xsubpp.
.IP "\(bu" 4
roll-your-own magic variables (including multiple simultaneous \s-1DBM\s0
implementations)
.Sp
Described in perltie and AnyDBM_File.
.IP "\(bu" 4
subroutines can now be overridden, autoloaded, and prototyped
.Sp
Described in perlsub.
.IP "\(bu" 4
arbitrarily nested data structures and anonymous functions
.Sp
Described in perlreftut, perlref, perldsc, and perllol.
.IP "\(bu" 4
object-oriented programming
.Sp
Described in perlobj, perlboot, perltoot, perltooc,
and perlbot.
.IP "\(bu" 4
support for light-weight processes (threads)
.Sp
Described in perlthrtut and threads.
.IP "\(bu" 4
support for Unicode, internationalization, and localization
.Sp
Described in perluniintro, perllocale and Locale::Maketext.
.IP "\(bu" 4
lexical scoping
.Sp
Described in perlsub.
.IP "\(bu" 4
regular expression enhancements
.Sp
Described in perlre, with additional examples in perlop.
.IP "\(bu" 4
enhanced debugger and interactive Perl environment,
with integrated editor support
.Sp
Described in perldebtut, perldebug and perldebguts.
.IP "\(bu" 4
\&\s-1POSIX\s0 1003.1 compliant library
.Sp
Described in \s-1POSIX\s0.
.PP
Okay, that's \fIdefinitely\fR enough hype.
.SH "AVAILABILITY"
.IX Header "AVAILABILITY"
Perl is available for most operating systems, including virtually
all Unix-like platforms.  See \*(L"Supported Platforms\*(R" in perlport
for a listing.
.SH "ENVIRONMENT"
.IX Header "ENVIRONMENT"
See perlrun.
.SH "AUTHOR"
.IX Header "AUTHOR"
Larry Wall <[e-mail]>, with the help of oodles of other folks.
.PP
If your Perl success stories and testimonials may be of help to others 
who wish to advocate the use of Perl in their applications, 
or if you wish to simply express your gratitude to Larry and the 
Perl developers, please write to perl\[e-mail] .
.SH "FILES"
.IX Header "FILES"
.Vb 1
\& "@INC"                 locations of perl libraries
.Ve
.SH "SEE ALSO"
.IX Header "SEE ALSO"
.Vb 2
\& a2p    awk to perl translator
\& s2p    sed to perl translator
\&
\& http://www.perl.org/       the Perl homepage
\& http://www.perl.com/       Perl articles (O\*(AqReilly)
\& http://www.cpan.org/       the Comprehensive Perl Archive
\& http://www.pm.org/         the Perl Mongers
.Ve
.SH "DIAGNOSTICS"
.IX Header "DIAGNOSTICS"
The \f(CW\*(C`use warnings\*(C'\fR pragma (and the \fB\-w\fR switch) produces some 
lovely diagnostics.
.PP
See perldiag for explanations of all Perl's diagnostics.  The \f(CW\*(C`use
diagnostics\*(C'\fR pragma automatically turns Perl's normally terse warnings
and errors into these longer forms.
.PP
Compilation errors will tell you the line number of the error, with an
indication of the next token or token type that was to be examined.
(In a script passed to Perl via \fB\-e\fR switches, each
\&\fB\-e\fR is counted as one line.)
.PP
Setuid scripts have additional constraints that can produce error
messages such as \*(L"Insecure dependency\*(R".  See perlsec.
.PP
Did we mention that you should definitely consider using the \fB\-w\fR
switch?
.SH "BUGS"
.IX Header "BUGS"
The \fB\-w\fR switch is not mandatory.
.PP
Perl is at the mercy of your machine's definitions of various
operations such as type casting, \fIatof()\fR, and floating-point
output with \fIsprintf()\fR.
.PP
If your stdio requires a seek or eof between reads and writes on a
particular stream, so does Perl.  (This doesn't apply to \fIsysread()\fR
and \fIsyswrite()\fR.)
.PP
While none of the built-in data types have any arbitrary size limits
(apart from memory size), there are still a few arbitrary limits:  a
given variable name may not be longer than 251 characters.  Line numbers
displayed by diagnostics are internally stored as short integers,
so they are limited to a maximum of 65535 (higher numbers usually being
affected by wraparound).
.PP
You may mail your bug reports (be sure to include full configuration
information as output by the myconfig program in the perl source
tree, or by \f(CW\*(C`perl \-V\*(C'\fR) to [e-mail] .  If you've succeeded
in compiling perl, the \fBperlbug\fR script in the \fIutils/\fR subdirectory
can be used to help mail in a bug report.
.PP
Perl actually stands for Pathologically Eclectic Rubbish Lister, but
don't tell anyone I said that.
.SH "NOTES"
.IX Header "NOTES"
The Perl motto is \*(L"There's more than one way to do it.\*(R"  Divining
how many more is left as an exercise to the reader.
.PP
The three principal virtues of a programmer are Laziness,
Impatience, and Hubris.  See the Camel Book for why.