perlos2.1

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.

.PP
.Vb 1
\&        extproc perl \-S \-my_opts
.Ve
.PP
rename your program to \fIfoo.cmd\fR, and start it by typing
.PP
.Vb 1
\&        foo arg1 arg2 arg3
.Ve
.PP
Note that because of stupid \s-1OS/2\s0 limitations the full path of the perl
script is not available when you use \f(CW\*(C`extproc\*(C'\fR, thus you are forced to
use \f(CW\*(C`\-S\*(C'\fR perl switch, and your script should be on the \f(CW\*(C`PATH\*(C'\fR. As a plus
side, if you know a full path to your script, you may still start it
with
.PP
.Vb 1
\&        perl ../../blah/foo.cmd arg1 arg2 arg3
.Ve
.PP
(note that the argument \f(CW\*(C`\-my_opts\*(C'\fR is taken care of by the \f(CW\*(C`extproc\*(C'\fR line
in your script, see "\f(CW\*(C`extproc\*(C'\fR on the first line").
.PP
To understand what the above \fImagic\fR does, read perl docs about \f(CW\*(C`\-S\*(C'\fR
switch \- see perlrun, and cmdref about \f(CW\*(C`extproc\*(C'\fR:
.PP
.Vb 4
\&        view perl perlrun
\&        man perlrun
\&        view cmdref extproc
\&        help extproc
.Ve
.PP
or whatever method you prefer.
.PP
There are also endless possibilities to use \fIexecutable extensions\fR of
4os2, \fIassociations\fR of \s-1WPS\s0 and so on... However, if you use
*nixish shell (like \fIsh.exe\fR supplied in the binary distribution),
you need to follow the syntax specified in \*(L"Switches\*(R" in perlrun.
.PP
Note that \fB\-S\fR switch supports scripts with additional extensions 
\&\fI.cmd\fR, \fI.btm\fR, \fI.bat\fR, \fI.pl\fR as well.
.Sh "Starting \s-1OS/2\s0 (and \s-1DOS\s0) programs under Perl"
.IX Subsection "Starting OS/2 (and DOS) programs under Perl"
This is what \fIsystem()\fR (see \*(L"system\*(R" in perlfunc), \f(CW\*(C`\`\`\*(C'\fR (see
\&\*(L"I/O Operators\*(R" in perlop), and \fIopen pipe\fR (see \*(L"open\*(R" in perlfunc)
are for. (Avoid \fIexec()\fR (see \*(L"exec\*(R" in perlfunc) unless you know what you
do).
.PP
Note however that to use some of these operators you need to have a
sh-syntax shell installed (see \*(L"Pdksh\*(R", 
\&\*(L"Frequently asked questions\*(R"), and perl should be able to find it
(see \*(L"\s-1PERL_SH_DIR\s0\*(R").
.PP
The cases when the shell is used are:
.IP "1." 4
One-argument \fIsystem()\fR (see \*(L"system\*(R" in perlfunc), \fIexec()\fR (see \*(L"exec\*(R" in perlfunc)
with redirection or shell meta-characters;
.IP "2." 4
Pipe-open (see \*(L"open\*(R" in perlfunc) with the command which contains redirection 
or shell meta-characters;
.IP "3." 4
Backticks \f(CW\*(C`\`\`\*(C'\fR (see \*(L"I/O Operators\*(R" in perlop) with the command which contains
redirection or shell meta-characters;
.IP "4." 4
If the executable called by \fIsystem()\fR/\fIexec()\fR/pipe\-\fIopen()\fR/\f(CW\*(C`\`\`\*(C'\fR is a script
with the \*(L"magic\*(R" \f(CW\*(C`#!\*(C'\fR line or \f(CW\*(C`extproc\*(C'\fR line which specifies shell;
.IP "5." 4
If the executable called by \fIsystem()\fR/\fIexec()\fR/pipe\-\fIopen()\fR/\f(CW\*(C`\`\`\*(C'\fR is a script
without \*(L"magic\*(R" line, and \f(CW$ENV{EXECSHELL}\fR is set to shell;
.IP "6." 4
If the executable called by \fIsystem()\fR/\fIexec()\fR/pipe\-\fIopen()\fR/\f(CW\*(C`\`\`\*(C'\fR is not
found (is not this remark obsolete?);
.IP "7." 4
For globbing (see \*(L"glob\*(R" in perlfunc, \*(L"I/O Operators\*(R" in perlop)
(obsolete? Perl uses builtin globbing nowadays...).
.PP
For the sake of speed for a common case, in the above algorithms 
backslashes in the command name are not considered as shell metacharacters.
.PP
Perl starts scripts which begin with cookies
\&\f(CW\*(C`extproc\*(C'\fR or \f(CW\*(C`#!\*(C'\fR directly, without an intervention of shell.  Perl uses the
same algorithm to find the executable as \fIpdksh\fR: if the path
on \f(CW\*(C`#!\*(C'\fR line does not work, and contains \f(CW\*(C`/\*(C'\fR, then the directory
part of the executable is ignored, and the executable
is searched in \fI.\fR and on \f(CW\*(C`PATH\*(C'\fR.  To find arguments for these scripts
Perl uses a different algorithm than \fIpdksh\fR: up to 3 arguments are 
recognized, and trailing whitespace is stripped.
.PP
If a script
does not contain such a cooky, then to avoid calling \fIsh.exe\fR, Perl uses
the same algorithm as \fIpdksh\fR: if \f(CW$ENV{EXECSHELL}\fR is set, the
script is given as the first argument to this command, if not set, then
\&\f(CW\*(C`$ENV{COMSPEC} /c\*(C'\fR is used (or a hardwired guess if \f(CW$ENV{COMSPEC}\fR is
not set).
.PP
When starting scripts directly, Perl uses exactly the same algorithm as for 
the search of script given by \fB\-S\fR command-line option: it will look in
the current directory, then on components of \f(CW$ENV{PATH}\fR using the 
following order of appended extensions: no extension, \fI.cmd\fR, \fI.btm\fR, 
\&\fI.bat\fR, \fI.pl\fR.
.PP
Note that Perl will start to look for scripts only if \s-1OS/2\s0 cannot start the
specified application, thus \f(CW\*(C`system \*(Aqblah\*(Aq\*(C'\fR will not look for a script if 
there is an executable file \fIblah.exe\fR \fIanywhere\fR on \f(CW\*(C`PATH\*(C'\fR.  In
other words, \f(CW\*(C`PATH\*(C'\fR is essentially searched twice: once by the \s-1OS\s0 for
an executable, then by Perl for scripts.
.PP
Note also that executable files on \s-1OS/2\s0 can have an arbitrary extension, 
but \fI.exe\fR will be automatically appended if no dot is present in the name.  
The workaround is as simple as that:  since \fIblah.\fR and \fIblah\fR denote the 
same file (at list on \s-1FAT\s0 and \s-1HPFS\s0 file systems), to start an executable residing in file \fIn:/bin/blah\fR (no 
extension) give an argument \f(CW\*(C`n:/bin/blah.\*(C'\fR (dot appended) to \fIsystem()\fR.
.PP
Perl will start \s-1PM\s0 programs from \s-1VIO\s0 (=text\-mode) Perl process in a
separate \s-1PM\s0 session;
the opposite is not true: when you start a non-PM program from a \s-1PM\s0
Perl process, Perl would not run it in a separate session.  If a separate
session is desired, either ensure
that shell will be used, as in \f(CW\*(C`system \*(Aqcmd /c myprog\*(Aq\*(C'\fR, or start it using
optional arguments to \fIsystem()\fR documented in \f(CW\*(C`OS2::Process\*(C'\fR module.  This
is considered to be a feature.
.SH "Frequently asked questions"
.IX Header "Frequently asked questions"
.ie n .Sh """It does not work"""
.el .Sh "``It does not work''"
.IX Subsection "It does not work"
Perl binary distributions come with a \fItestperl.cmd\fR script which tries
to detect common problems with misconfigured installations.  There is a
pretty large chance it will discover which step of the installation you
managed to goof.  \f(CW\*(C`;\-)\*(C'\fR
.Sh "I cannot run external programs"
.IX Subsection "I cannot run external programs"
.IP "\(bu" 4
Did you run your programs with \f(CW\*(C`\-w\*(C'\fR switch? See 
\&\*(L"2 (and \s-1DOS\s0) programs under Perl\*(R" in Starting \s-1OS\s0.
.IP "\(bu" 4
Do you try to run \fIinternal\fR shell commands, like \f(CW\*(C`\`copy a b\`\*(C'\fR
(internal for \fIcmd.exe\fR), or \f(CW\*(C`\`glob a*b\`\*(C'\fR (internal for ksh)? You
need to specify your shell explicitly, like \f(CW\*(C`\`cmd /c copy a b\`\*(C'\fR,
since Perl cannot deduce which commands are internal to your shell.
.Sh "I cannot embed perl into my program, or use \fIperl.dll\fP from my program."
.IX Subsection "I cannot embed perl into my program, or use perl.dll from my program."
.ie n .IP "Is your program EMX-compiled with ""\-Zmt \-Zcrtdll""?" 4
.el .IP "Is your program EMX-compiled with \f(CW\-Zmt \-Zcrtdll\fR?" 4
.IX Item "Is your program EMX-compiled with -Zmt -Zcrtdll?"
Well, nowadays Perl \s-1DLL\s0 should be usable from a differently compiled
program too...  If you can run Perl code from \s-1REXX\s0 scripts (see
\&\s-1OS2::REXX\s0), then there are some other aspect of interaction which
are overlooked by the current hackish code to support
differently-compiled principal programs.
.Sp
If everything else fails, you need to build a stand-alone \s-1DLL\s0 for
perl. Contact me, I did it once. Sockets would not work, as a lot of
other stuff.
.IP "Did you use ExtUtils::Embed?" 4
.IX Item "Did you use ExtUtils::Embed?"
Some time ago I had reports it does not work.  Nowadays it is checked
in the Perl test suite, so grep \fI./t\fR subdirectory of the build tree
(as well as \fI*.t\fR files in the \fI./lib\fR subdirectory) to find how it
should be done \*(L"correctly\*(R".
.ie n .Sh """\`\`""\fP and pipe\-\f(CW""open"" do not work under \s-1DOS\s0."
.el .Sh "\f(CW\`\`\fP and pipe\-\f(CWopen\fP do not work under \s-1DOS\s0."
.IX Subsection " and pipe-open do not work under DOS."
This may a variant of just \*(L"I cannot run external programs\*(R", or a
deeper problem. Basically: you \fIneed\fR \s-1RSX\s0 (see \*(L"Prerequisites\*(R")
for these commands to work, and you may need a port of \fIsh.exe\fR which
understands command arguments. One of such ports is listed in
\&\*(L"Prerequisites\*(R" under \s-1RSX\s0. Do not forget to set variable
\&\f(CW"PERL_SH_DIR"\fR as well.
.PP
\&\s-1DPMI\s0 is required for \s-1RSX\s0.
.ie n .Sh "Cannot start ""find.exe ""pattern"" file"""
.el .Sh "Cannot start \f(CWfind.exe ``pattern'' file\fP"
.IX Subsection "Cannot start find.exe ""pattern"" file"
The whole idea of the \*(L"standard C \s-1API\s0 to start applications\*(R" is that
the forms \f(CW\*(C`foo\*(C'\fR and \f(CW"foo"\fR of program arguments are completely
interchangable.  \fIfind\fR breaks this paradigm;
.PP
.Vb 2
\&  find "pattern" file
\&  find pattern file
.Ve
.PP
are not equivalent; \fIfind\fR cannot be started directly using the above
\&\s-1API\s0.  One needs a way to surround the doublequotes in some other
quoting construction, necessarily having an extra non-Unixish shell in
between.
.PP
Use one of
.PP
.Vb 2
\&  system \*(Aqcmd\*(Aq, \*(Aq/c\*(Aq, \*(Aqfind "pattern" file\*(Aq;
\&  \`cmd /c \*(Aqfind "pattern" file\*(Aq\`
.Ve
.PP
This would start \fIfind.exe\fR via \fIcmd.exe\fR via \f(CW\*(C`sh.exe\*(C'\fR via
\&\f(CW\*(C`perl.exe\*(C'\fR, but this is a price to pay if you want to use
non-conforming program.
.SH "INSTALLATION"
.IX Header "INSTALLATION"
.Sh "Automatic binary installation"
.IX Subsection "Automatic binary installation"
The most convenient way of installing a binary distribution of perl is via perl installer
\&\fIinstall.exe\fR. Just follow the instructions, and 99% of the
installation blues would go away.
.PP
Note however, that you need to have \fIunzip.exe\fR on your path, and
\&\s-1EMX\s0 environment \fIrunning\fR. The latter means that if you just
installed \s-1EMX\s0, and made all the needed changes to \fIConfig.sys\fR,
you may need to reboot in between. Check \s-1EMX\s0 runtime by running
.PP
.Vb 1
\&        emxrev
.Ve
.PP
Binary installer also creates a folder on your desktop with some useful
objects.  If you need to change some aspects of the work of the binary
installer, feel free to edit the file \fIPerl.pkg\fR.  This may be useful
e.g., if you need to run the installer many times and do not want to
make many interactive changes in the \s-1GUI\s0.
.PP
\&\fBThings not taken care of by automatic binary installation:\fR
.ie n .IP """PERL_BADLANG""" 15
.el .IP "\f(CWPERL_BADLANG\fR" 15
.IX Item "PERL_BADLANG"
may be needed if you change your codepage \fIafter\fR perl installation,
and the new value is not supported by \s-1EMX\s0. See \*(L"\s-1PERL_BADLANG\s0\*(R".
.ie n .IP """PERL_BADFREE""" 15
.el .IP "\f(CWPERL_BADFREE\fR" 15
.IX Item "PERL_BADFREE"
see \*(L"\s-1PERL_BADFREE\s0\*(R".
.IP "\fIConfig.pm\fR" 15
.IX Item "Config.pm"
This file resides somewhere deep in the location you installed your
perl library, find it out by
.Sp
.Vb 1
\&  perl \-MConfig \-le "print $INC{\*(AqConfig.pm\*(Aq}"
.Ve
.Sp
While most important values in this file \fIare\fR updated by the binary
installer, some of them may need to be hand-edited. I know no such
data, please keep me informed if you find one.  Moreover, manual
changes to the installed version may need to be accompanied by an edit
of this file.
.PP
\&\fB\s-1NOTE\s0\fR. Because of a typo the binary installer of 5.00305
would install a variable \f(CW\*(C`PERL_SHPATH\*(C'\fR into \fIConfig.sys\fR. Please
remove this variable and put \f(CW\*(C`PERL_SH_DIR\*(C'\fR instead.
.Sh "Manual binary installation"
.IX Subsection "Manual binary installation"
As of version 5.00305, \s-1OS/2\s0 perl binary distribution comes split
into 11 components. Unfortunately, to enable configurable binary
installation, the file paths in the zip files are not absolute, but
relative to some directory.
.PP
Note that the extraction with the stored paths is still necessary
(default with unzip, specify \f(CW\*(C`\-d\*(C'\fR to pkunzip). However, you
need to know where to extract the files. You need also to manually
change entries in \fIConfig.sys\fR to reflect where did you put the
files. Note that if you have some primitive unzipper (like
\&\f(CW\*(C`pkunzip\*(C'\fR), you may get a lot of warnings/errors during
unzipping. Upgrade to \f(CW\*(C`(w)unzip\*(C'\fR.
.PP
Below is the sample of what to do to reproduce the configuration on my
machine.  In \fI\s-1VIEW\s0.EXE\fR you can press \f(CW\*(C`Ctrl\-Insert\*(C'\fR now, and
cut-and-paste from the resulting file \- created in the directory you
started \fI\s-1VIEW\s0.EXE\fR from.
.PP
For each component, we mention environment variables related to each
installation directory.  Either choose directories to match your
values of the variables, or create/append\-to variables to take into
account the directories.
.IP "Perl \s-1VIO\s0 and \s-1PM\s0 executables (dynamically linked)" 3
.IX Item "Perl VIO and PM executables (dynamically linked)"
.Vb 2
\&  unzip perl_exc.zip *.exe *.ico \-d f:/emx.add/bin
\&  unzip perl_exc.zip *.dll \-d f:/emx.add/dll
.Ve
.Sp
(have the directories with \f(CW\*(C`*.exe\*(C'\fR on \s-1PATH\s0, and \f(CW\*(C`*.dll\*(C'\fR on
\&\s-1LIBPATH\s0);
.IP "Perl_ \s-1VIO\s0 executable (statically linked)" 3
.IX Item "Perl_ VIO executable (statically linked)"
.Vb 1
\&  unzip perl_aou.zip \-d f:/emx.add/bin
.Ve
.Sp
(have the directory on \s-1PATH\s0);
.IP "Executables for Perl utilities" 3
.IX Item "Executables for Perl utilities"
.Vb 1
\&  unzip perl_utl.zip \-d f:/emx.add/bin
.Ve
.Sp
(have the directory on \s-1PATH\s0);
.IP "Main Perl library" 3
.IX Item "Main Perl library"
.Vb 1
\&  unzip perl_mlb.zip \-d f:/perllib/lib
.Ve
.Sp
If this directory is exactly the same as the prefix which was compiled
into \fIperl.exe\fR, you do not need to change
anything. However, for perl to find the library if you use a different
path, you need to
\&\f(CW\*(C`set PERLLIB_PREFIX\*(C'\fR in \fIConfig.sys\fR, see \*(L"\s-1PERLLIB_PREFIX\s0\*(R".
.IP "Additional Perl modules" 3
.IX Item "Additional Perl modules"
.Vb 1
\&  unzip perl_ste.zip \-d f:/perllib/lib/site_perl/5.8.3/
.Ve
.Sp
Same remark as above applies.  Additionally, if this directory is not
one of directories on \f(CW@INC\fR (and \f(CW@INC\fR is influenced by \f(CW\*(C`PERLLIB_PREFIX\*(C'\fR), you
need to put this
directory and subdirectory \fI./os2\fR in \f(CW\*(C`PERLLIB\*(C'\fR or \f(CW\*(C`PERL5LIB\*(C'\fR
variable. Do not use \f(CW\*(C`PERL5LIB\*(C'\fR unless you have it set already. See
\&\*(L"\s-1ENVIRONMENT\s0\*(R" in perl.
.Sp
\&\fB[Check whether this extraction directory is still applicable with
the new directory structure layout!]\fR
.IP "Tools to compile Perl modules" 3
.IX Item "Tools to compile Perl modules"
.Vb 1
\&  unzip perl_blb.zip \-d f:/perllib/lib