perlos390.1

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.

Some of the configuration files in /etc used by the
networking APIs are either missing or have the wrong
names.  In particular, make sure that there's either
an /etc/resolv.conf or an /etc/hosts, so that
\&\fIgethostbyname()\fR works, and make sure that the file
/etc/proto has been renamed to /etc/protocol (\s-1NOT\s0
/etc/protocols, as used by other Unix systems).
You may have to look for things like \s-1HOSTNAME\s0 and \s-1DOMAINORIGIN\s0
in the \*(L"//'\s-1SYS1\s0.TCPPARMS(\s-1TCPDATA\s0)'\*(R" \s-1PDS\s0 member in order to
properly set up your /etc networking files.
.Sh "Build, Test, Install Perl on \s-1OS/390\s0"
.IX Subsection "Build, Test, Install Perl on OS/390"
Simply put:
.PP
.Vb 3
\&    sh Configure
\&    make
\&    make test
.Ve
.PP
if everything looks ok (see the next section for test/IVP diagnosis) then:
.PP
.Vb 1
\&    make install
.Ve
.PP
this last step may or may not require UID=0 privileges depending
on how you answered the questions that Configure asked and whether
or not you have write access to the directories you specified.
.Sh "Build Anomalies with Perl on \s-1OS/390\s0"
.IX Subsection "Build Anomalies with Perl on OS/390"
\&\*(L"Out of memory!\*(R" messages during the build of Perl are most often fixed
by re building the \s-1GNU\s0 make utility for \s-1OS/390\s0 from a source code kit.
.PP
Another memory limiting item to check is your \s-1MAXASSIZE\s0 parameter in your
\&'\s-1SYS1\s0.PARMLIB(BPXPRMxx)' data set (note too that as of V2R8 address space
limits can be set on a per user \s-1ID\s0 basis in the \s-1USS\s0 segment of a \s-1RACF\s0
profile).  People have reported successful builds of Perl with \s-1MAXASSIZE\s0
parameters as small as 503316480 (and it may be possible to build Perl
with a \s-1MAXASSIZE\s0 smaller than that).
.PP
Within \s-1USS\s0 your /etc/profile or \f(CW$HOME\fR/.profile may limit your ulimit
settings.  Check that the following command returns reasonable values:
.PP
.Vb 1
\&    ulimit \-a
.Ve
.PP
To conserve memory you should have your compiler modules loaded into the
Link Pack Area (\s-1LPA/ELPA\s0) rather than in a link list or step lib.
.PP
If the c89 compiler complains of syntax errors during the build of the
Socket extension then be sure to fix the syntax error in the system
header /usr/include/sys/socket.h.
.Sh "Testing Anomalies with Perl on \s-1OS/390\s0"
.IX Subsection "Testing Anomalies with Perl on OS/390"
The \*(L"make test\*(R" step runs a Perl Verification Procedure, usually before
installation.  You might encounter \s-1STDERR\s0 messages even during a successful
run of \*(L"make test\*(R".  Here is a guide to some of the more commonly seen
anomalies:
.IP "\(bu" 4
A message of the form:
.Sp
.Vb 5
\& comp/cpp.............ERROR CBC3191 ./.301989890.c:1     The character $ is not a
\&  valid C source character.
\& FSUM3065 The COMPILE step ended with return code 12.
\& FSUM3017 Could not compile .301989890.c. Correct the errors and try again.
\& ok
.Ve
.Sp
indicates that the t/comp/cpp.t test of Perl's \-P command line switch has
passed but that the particular invocation of c89 \-E in the cpp script does
not suppress the C compiler check of source code validity.
.IP "\(bu" 4
A message of the form:
.Sp
.Vb 4
\& io/openpid...........CEE5210S The signal SIGHUP was received.
\& CEE5210S The signal SIGHUP was received.
\& CEE5210S The signal SIGHUP was received.
\& ok
.Ve
.Sp
indicates that the t/io/openpid.t test of Perl has passed but done so
with extraneous messages on stderr from \s-1CEE\s0.
.IP "\(bu" 4
A message of the form:
.Sp
.Vb 5
\& lib/ftmp\-security....File::Temp::_gettemp: Parent directory (/tmp/) is not safe
\& (sticky bit not set when world writable?) at lib/ftmp\-security.t line 100
\& File::Temp::_gettemp: Parent directory (/tmp/) is not safe (sticky bit not
\& set when world writable?) at lib/ftmp\-security.t line 100
\& ok
.Ve
.Sp
indicates a problem with the permissions on your /tmp directory within the \s-1HFS\s0.
To correct that problem issue the command:
.Sp
.Vb 1
\&     chmod a+t /tmp
.Ve
.Sp
from an account with write access to the directory entry for /tmp.
.IP "\(bu" 4
Out of Memory!
.Sp
Recent perl test suite is quite memory hunrgy. In addition to the comments
above on memory limitations it is also worth checking for _CEE_RUNOPTS
in your environment. Perl now has (in miniperlmain.c) a C #pragma
to set \s-1CEE\s0 run options, but the environment variable wins.
.Sp
The C code asks for:
.Sp
.Vb 1
\& #pragma runopts(HEAP(2M,500K,ANYWHERE,KEEP,8K,4K) STACK(,,ANY,) ALL31(ON))
.Ve
.Sp
The important parts of that are the second argument (the increment) to \s-1HEAP\s0,
and allowing the stack to be \*(L"Above the (16M) line\*(R". If the heap
increment is too small then when perl (for example loading unicode/Name.pl) tries
to create a \*(L"big\*(R" (400K+) string it cannot fit in a single segment
and you get \*(L"Out of Memory!\*(R" \- even if there is still plenty of memory
available.
.Sp
A related issue is use with perl's malloc. Perl's malloc uses \f(CW\*(C`sbrk()\*(C'\fR
to get memory, and \f(CW\*(C`sbrk()\*(C'\fR is limited to the first allocation so in this
case something like:
.Sp
.Vb 1
\&  HEAP(8M,500K,ANYWHERE,KEEP,8K,4K)
.Ve
.Sp
is needed to get through the test suite.
.Sh "Installation Anomalies with Perl on \s-1OS/390\s0"
.IX Subsection "Installation Anomalies with Perl on OS/390"
The installman script will try to run on \s-1OS/390\s0.  There will be fewer errors
if you have a roff utility installed.  You can obtain \s-1GNU\s0 groff from the
Redbook \s-1SG24\-5944\-00\s0 ftp site.
.Sh "Usage Hints for Perl on \s-1OS/390\s0"
.IX Subsection "Usage Hints for Perl on OS/390"
When using perl on \s-1OS/390\s0 please keep in mind that the \s-1EBCDIC\s0 and \s-1ASCII\s0
character sets are different.  See perlebcdic.pod for more on such character
set issues.  Perl builtin functions that may behave differently under
\&\s-1EBCDIC\s0 are also mentioned in the perlport.pod document.
.PP
Open Edition (\s-1UNIX\s0 System Services) from V2R8 onward does support
#!/path/to/perl script invocation.  There is a \s-1PTF\s0 available from
\&\s-1IBM\s0 for V2R7 that will allow shell/kernel support for #!.  \s-1USS\s0
releases prior to V2R7 did not support the #! means of script invocation.
If you are running V2R6 or earlier then see:
.PP
.Vb 1
\&    head \`whence perldoc\`
.Ve
.PP
for an example of how to use the \*(L"eval exec\*(R" trick to ask the shell to
have Perl run your scripts on those older releases of Unix System Services.
.PP
If you are having trouble with square brackets then consider switching your
rlogin or telnet client.  Try to avoid older 3270 emulators and \s-1ISHELL\s0 for
working with Perl on \s-1USS\s0.
.Sh "Floating Point Anomalies with Perl on \s-1OS/390\s0"
.IX Subsection "Floating Point Anomalies with Perl on OS/390"
There appears to be a bug in the floating point implementation on S/390
systems such that calling \fIint()\fR on the product of a number and a small
magnitude number is not the same as calling \fIint()\fR on the quotient of
that number and a large magnitude number.  For example, in the following
Perl code:
.PP
.Vb 4
\&    my $x = 100000.0;
\&    my $y = int($x * 1e\-5) * 1e5; # \*(Aq0\*(Aq
\&    my $z = int($x / 1e+5) * 1e5;  # \*(Aq100000\*(Aq
\&    print "\e$y is $y and \e$z is $z\en"; # $y is 0 and $z is 100000
.Ve
.PP
Although one would expect the quantities \f(CW$y\fR and \f(CW$z\fR to be the same and equal
to 100000 they will differ and instead will be 0 and 100000 respectively.
.PP
The problem can be further examined in a roughly equivalent C program:
.PP
.Vb 10
\&    #include <stdio.h>
\&    #include <math.h>
\&    main()
\&    {
\&    double r1,r2;
\&    double x = 100000.0;
\&    double y = 0.0;
\&    double z = 0.0;
\&    x = 100000.0 * 1e\-5;
\&    r1 = modf (x,&y);
\&    x = 100000.0 / 1e+5;
\&    r2 = modf (x,&z);
\&    printf("y is %e and z is %e\en",y*1e5,z*1e5);
\&    /* y is 0.000000e+00 and z is 1.000000e+05 (with c89) */
\&    }
.Ve
.Sh "Modules and Extensions for Perl on \s-1OS/390\s0"
.IX Subsection "Modules and Extensions for Perl on OS/390"
Pure pure (that is non xs) modules may be installed via the usual:
.PP
.Vb 4
\&    perl Makefile.PL
\&    make
\&    make test
\&    make install
.Ve
.PP
If you built perl with dynamic loading capability then that would also
be the way to build xs based extensions.  However, if you built perl with
the default static linking you can still build xs based extensions for \s-1OS/390\s0
but you will need to follow the instructions in ExtUtils::MakeMaker for
building statically linked perl binaries.  In the simplest configurations
building a static perl + xs extension boils down to:
.PP
.Vb 6
\&    perl Makefile.PL
\&    make
\&    make perl
\&    make test
\&    make install
\&    make \-f Makefile.aperl inst_perl MAP_TARGET=perl
.Ve
.PP
In most cases people have reported better results with \s-1GNU\s0 make rather
than the system's /bin/make program, whether for plain modules or for
xs based extensions.
.PP
If the make process encounters trouble with either compilation or
linking then try setting the _C89_CCMODE to 1.  Assuming sh is your
login shell then run:
.PP
.Vb 1
\&    export _C89_CCMODE=1
.Ve
.PP
If tcsh is your login shell then use the setenv command.
.SH "AUTHORS"
.IX Header "AUTHORS"
David Fiander and Peter Prymmer with thanks to Dennis Longnecker
and William Raffloer for valuable reports, \s-1LPAR\s0 and \s-1PTF\s0 feedback.
Thanks to Mike MacIsaac and Egon Terwedow for \s-1SG24\-5944\-00\s0.
Thanks to Ignasi Roca for pointing out the floating point problems.
Thanks to John Goodyear for dynamic loading help.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\s-1INSTALL\s0, perlport, perlebcdic, ExtUtils::MakeMaker.
.PP
.Vb 1
\&    http://www\-1.ibm.com/servers/eserver/zseries/zos/unix/bpxa1toy.html
\&
\&    http://www.redbooks.ibm.com/abstracts/sg245944.html
\&
\&    http://www\-1.ibm.com/servers/eserver/zseries/zos/unix/bpxa1ty1.html#opensrc
\&
\&    http://www.xray.mpe.mpg.de/mailing\-lists/perl\-mvs/
\&
\&    http://publibz.boulder.ibm.com:80/cgi\-bin/bookmgr_OS390/BOOKS/ceea3030/
\&
\&    http://publibz.boulder.ibm.com:80/cgi\-bin/bookmgr_OS390/BOOKS/CBCUG030/
.Ve
.Sh "Mailing list for Perl on \s-1OS/390\s0"
.IX Subsection "Mailing list for Perl on OS/390"
If you are interested in the \s-1VM/ESA\s0, z/OS (formerly known as \s-1OS/390\s0)
and POSIX-BC (\s-1BS2000\s0) ports of Perl then see the perl-mvs mailing list.
To subscribe, send an empty message to perl\-mvs\[e-mail].
.PP
See also:
.PP
.Vb 1
\&    http://lists.perl.org/showlist.cgi?name=perl\-mvs
.Ve
.PP
There are web archives of the mailing list at:
.PP
.Vb 2
\&    http://www.xray.mpe.mpg.de/mailing\-lists/perl\-mvs/
\&    http://archive.develooper.com/perl\[e-mail]/
.Ve
.SH "HISTORY"
.IX Header "HISTORY"
This document was originally written by David Fiander for the 5.005
release of Perl.
.PP
This document was podified for the 5.005_03 release of Perl 11 March 1999.
.PP
Updated 28 November 2001 for broken URLs.
.PP
Updated 12 November 2000 for the 5.7.1 release of Perl.
.PP
Updated 15 January 2001 for the 5.7.1 release of Perl.
.PP
Updated 24 January 2001 to mention dynamic loading.
.PP
Updated 12 March 2001 to mention //'\s-1SYS1\s0.TCPPARMS(\s-1TCPDATA\s0)'.