X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/80a5d8e74b5512d4ab704d0e83466ae41247ce55..HEAD:/README.os390?ds=sidebyside diff --git a/README.os390 b/README.os390 index d3b299b..3cadfe2 100644 --- a/README.os390 +++ b/README.os390 @@ -1,212 +1,268 @@ +# vim: syntax=pod + This document is written in pod format hence there are punctuation -characters in odd places. Do not worry, you've apparently got the -ASCII->EBCDIC translation worked out correctly. You can read more +characters in odd places. You can read more about pod in pod/perlpod.pod or the short summary in the INSTALL file. =head1 NAME -README.os390 - building and installing Perl for OS/390 and z/OS +perlos390 - building and installing Perl for z/OS (previously called OS/390) =head1 SYNOPSIS This document will help you Configure, build, test and install Perl -on OS/390 (aka z/OS) Unix System Services. +on z/OS Unix System Services. =head1 DESCRIPTION -This is a fully ported Perl for OS/390 Version 2 Release 3, 5, 6, 7, -8, and 9. It may work on other versions or releases, but those are -the ones we've tested it on. +This is a ported Perl for z/OS. It has been tested on z/OS 2.4 and +should work fine with z/OS 2.5. +It may work on other versions or releases, but those are +the ones it has been tested on. -You may need to carry out some system configuration tasks before -running the Configure script for Perl. +The native character set for z/OS is EBCDIC, but it can also run in ASCII mode. +Perl can support either, but you have to compile it explicitly for one or the +other. You could have both an ASCII perl, and an EBCDIC perl on the same +machine. If you use ASCII mode and an ASCII perl, the Encode module shipped +with perl can be used to translate files from various EBCDIC code pages for +handling by perl, and then back on output +This document describes how to build a 64-bit Dynamic Perl, either ASCII or +EBCDIC. You can interactively choose other configurations, as well as many +other options in the Configure script that is run as part of the build +process. You may need to carry out some system configuration tasks before +running Configure, as detailed below. =head2 Tools -The z/OS Unix Tools and Toys list may prove helpful and contains links -to ports of much of the software helpful for building Perl. -http://www-1.ibm.com/servers/eserver/zseries/zos/unix/bpxa1toy.html +You will want to get GNU make 4.1 or later. GNU make can be downloaded from a +port that Rocket Software provides. You will need the z/OS c99 compiler from +IBM (though xlc in c99 mode without optimization turned on works in EBCDIC). +If you want the latest development version of Perl, you will need git. +You can use git on another platform and transfer the result via sftp or ftp to +z/OS. But there is a z/OS native git client port available through Rocket +Software. -=head2 Unpacking Perl distribution on OS/390 +You may also need the gunzip client port that Rocket Software provides to unzip +any zipped tarball you upload to z/OS. -If using ftp remember to transfer the distribution in binary format. +=head2 Building a 64-bit Dynamic ASCII Perl -Gunzip/gzip for OS/390 is discussed at: +For building from an official stable release of Perl, go to +L and choose any one of the +"Download latest stable source" buttons. This will get you a tarball. The +name of that tarball will be something like 'perl-V.R.M,tar,gz', where V.R.M is +the version/release/modification of the perl you are downloading. Do - http://www-1.ibm.com/servers/eserver/zseries/zos/unix/faq/bpxqp1.html + gunzip perl-V.R.M.tar.gz -to extract an ASCII tar archive on OS/390, try this: +Then one of: - pax -o to=IBM-1047,from=ISO8859-1 -r < latest.tar + tar -xvf perl-V.R.M.tar -or + pax -r -f perl-V.R.M.tar - zcat latest.tar.Z | pax -o to=IBM-1047,from=ISO8859-1 -r +Either of these will create the source directory. You can rename it to +whatever you like; for these instructions, 'perl' is assumed to be the name. -If you get lots of errors of the form +If instead you want the latest unstable development release, using the native +git on z/OS, clone Perl: - tar: FSUM7171 ...: cannot set uid/gid: EDC5139I Operation not permitted. + git clone https://github.com/Perl/perl5.git perl -you didn't read the above and tried to use tar instead of pax, you'll -first have to remove the (now corrupt) perl directory +Either way, once you have a 'perl' directory containing the source, cd into it, +and tag all the code as ASCII: - rm -rf perl-... + cd perl + chtag -R -h -t -cISO8859-1 * -and then use pax. +Configure the build environment as 64-bit, Dynamic, ASCII, development, +deploying it to F: -=head2 Setup and utilities for Perl on OS/390 + export PATH=$PWD:$PATH + export LIBPATH=$PWD:$PATH + ./Configure -Dprefix=/usr/local/perl/ascii -des -Dusedevel \ + -Duse64bitall -Dusedl -Be sure that your yacc installation is in place including any necessary -parser template files. If you have not already done so then be sure to: +If you are building from a stable source, you don't need "-Dusedevel". +(If you run Configure without options, it will interactively ask you about +every possible option based on its probing of what's available on your +particular machine, so you can choose as you go along.) - cp /samples/yyparse.c /etc +Run GNU make to build Perl -This may also be a good time to ensure that your /etc/protocol file -and either your /etc/resolv.conf or /etc/hosts files are in place. -The IBM document that described such USS system setup issues was -SC28-1890-07 "OS/390 UNIX System Services Planning", in particular -Chapter 6 on customizing the OE shell. + make -GNU make for OS/390, which is recommended for the build of perl (as -well as building CPAN modules and extensions), is available from the -L. +Run tests to ensure Perl is working correctly. Currently, there are about a +dozen failing tests out of nearly 2500 -Some people have reported encountering "Out of memory!" errors while -trying to build Perl using GNU make binaries. If you encounter such -trouble then try to download the source code kit and build GNU make -from source to eliminate any such trouble. You might also find GNU make -(as well as Perl and Apache) in the red-piece/book "Open Source Software -for OS/390 UNIX", SG24-5944-00 from IBM. + make test_harness -If instead of the recommended GNU make you would like to use the system -supplied make program then be sure to install the default rules file -properly via the shell command: +Install Perl into F: - cp /samples/startup.mk /etc + make install -and be sure to also set the environment variable _C89_CCMODE=1 (exporting -_C89_CCMODE=1 is also a good idea for users of GNU make). +=head2 Building a 64-bit Dynamic EBCDIC Perl -You might also want to have GNU groff for OS/390 installed before -running the `make install` step for Perl. +You will need a working perl on some box with connectivity to the destination +machine. On z/OS, it could be an ASCII perl, or a previous EBCDIC one. +Many machines will already have a pre-built perl already running, or one can +easily be downloaded from L. -There is a syntax error in the /usr/include/sys/socket.h header file -that IBM supplies with USS V2R7, V2R8, and possibly V2R9. The problem with -the header file is that near the definition of the SO_REUSEPORT constant -there is a spurious extra '/' character outside of a comment like so: +Follow the directions above in "Building a 64-bit Dynamic ASCII Perl" as far as +getting a populated 'perl' directory. Then come back here to proceed. - #define SO_REUSEPORT 0x0200 /* allow local address & port - reuse */ / +The downloaded perl will need to be converted to 1047 EBCDIC. To do this: -You could edit that header yourself to remove that last '/', or you might -note that Language Environment (LE) APAR PQ39997 describes the problem -and PTF's UQ46272 and UQ46271 are the (R8 at least) fixes and apply them. -If left unattended that syntax error will turn up as an inability for Perl -to build its "Socket" extension. + cd perl + Porting/makerel -e -For successful testing you may need to turn on the sticky bit for your -world readable /tmp directory if you have not already done so (see man chmod). +If the Porting/makerel step fails with an error that it can not issue the tar +command, proceed to issue the command interactively, where V.R.M is the +version/release/modification of Perl you are uploading: -=head2 Configure Perl on OS/390 + cd ../ + tar cf - --format=ustar perl-V.R.M | gzip --best > perl-V.R.M.tar.gz -Once you've unpacked the distribution, run "sh Configure" (see INSTALL -for a full discussion of the Configure options). There is a "hints" file -for os390 that specifies the correct values for most things. Some things -to watch out for include: +Use sftp to upload the zipped tar file to z/OS: -=over 4 + sftp + cd /tmp + put perl-V.R.M.tar.gz -=item * +Unzip and untar the zipped tar file on z/OS: -A message of the form: + cd /tmp + gunzip perl-V.R.M.tar.gz - (I see you are using the Korn shell. Some ksh's blow up on Configure, - mainly on older exotic systems. If yours does, try the Bourne shell instead.) +Then one of: -is nothing to worry about at all. + tar -xvf perl-V.R.M.tar -=item * + pax -r -f perl-V.R.M.tar -Some of the parser default template files in /samples are needed in /etc. -In particular be sure that you at least copy /samples/yyparse.c to /etc -before running Perl's Configure. This step ensures successful extraction -of EBCDIC versions of parser files such as perly.c, perly.h, and x2p/a2p.c. -This has to be done before running Configure the first time. If you failed -to do so then the easiest way to re-Configure Perl is to delete your -misconfigured build root and re-extract the source from the tar ball. -Then you must ensure that /etc/yyparse.c is properly in place before -attempting to re-run Configure. +You now have the source code for the EBCDIC Perl on z/OS and can proceed to +build it. This is analagous to how you would build the code for ASCII, but +note: you B tag the code but instead leave it untagged. -=item * +Configure the build environment as 64-bit, Dynamic, native, development, +deploying it to F: -This port will support dynamic loading, but it is not selected by -default. If you would like to experiment with dynamic loading then -be sure to specify -Dusedl in the arguments to the Configure script. -See the comments in hints/os390.sh for more information on dynamic loading. -If you build with dynamic loading then you will need to add the -$archlibexp/CORE directory to your LIBPATH environment variable in order -for perl to work. See the config.sh file for the value of $archlibexp. -If in trying to use Perl you see an error message similar to: + export PATH=$PWD:$PATH + export LIBPATH=$PWD:$PATH + ./Configure -Dprefix=/usr/local/perl/ebcdic -des -Dusedevel \ + -Duse64bitall -Dusedl - CEE3501S The module libperl.dll was not found. - From entry point __dllstaticinit at compile unit offset +00000194 at +If you are building from a stable source, you don't need "-Dusedevel". +(If you run Configure without options, it will interactively ask you about +every possible option based on its probing of what's available on your +particular machine, so you can choose as you go along.) -then your LIBPATH does not have the location of libperl.x and either -libperl.dll or libperl.so in it. Add that directory to your LIBPATH and -proceed. +Run GNU make to build Perl -=item * + make -Do not turn on the compiler optimization flag "-O". There is -a bug in either the optimizer or perl that causes perl to -not work correctly when the optimizer is on. +Run tests to ensure Perl is working correctly. -=item * + make test_harness -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 -gethostbyname() works, and make sure that the file -/etc/proto has been renamed to /etc/protocol (NOT -/etc/protocols, as used by other Unix systems). -You may have to look for things like HOSTNAME and DOMAINORIGIN -in the "//'SYS1.TCPPARMS(TCPDATA)'" PDS member in order to -properly set up your /etc networking files. +You might also want to have GNU groff for OS/390 installed before +running the "make install" step for Perl. + +Install Perl into F: + + make install + +EBCDIC Perl is still a work in progress. All the core code works as far as we +know, but various modules you might want to download from CPAN do not. The +failures range from very minor to catastrophic. Many of them are simply bugs +in the tests, with the module actually working properly. This happens because, +for example, the test is coded to expect a certain character ASCII code point; +when it gets the EBCDIC value back instead, it complains. But the code +actually worked. Other potential failures that aren't really failures stem +from checksums coming out differently, since C, for example, has a different +bit representation between the character sets. A test that is expecting the +ASCII value will show failure, even if the module is working perfectly. Also +in sorting, uppercase letters come before lowercase letters on ASCII systems; +the reverse on EBCDIC. + +Some CPAN modules come bundled with the downloaded perl. And a few of those +have yet to be fixed to pass on EBCDIC platforms. As a result they are skipped +when you run 'make test'. The current list is: + + Archive::Tar + Config::Perl::V + CPAN::Meta + CPAN::Meta::YAML + Digest::MD5 + Digest::SHA + Encode + ExtUtils::MakeMaker + ExtUtils::Manifest + HTTP::Tiny + IO::Compress + IPC::Cmd + JSON::PP + libnet + MIME::Base64 + Module::Metadata + PerlIO::via-QuotedPrint + Pod::Checker + podlators + Pod::Simple + Socket + Test::Harness + +See also F for other potential gotchas. -=back +=head2 Setup and utilities for Perl on OS/390 -=head2 Build, Test, Install Perl on OS/390 +This may also be a good time to ensure that your F file +and either your F or F files are in place. +The IBM document that describes such USS system setup issues is +"z/OS UNIX System Services Planning" -Simply put: +For successful testing you may need to turn on the sticky bit for your +world readable /tmp directory if you have not already done so (see man chmod). - sh Configure - make - make test +=head2 Useful files for trouble-shooting -if everything looks ok (see the next section for test/IVP diagnosis) then: +If your configuration is failing, read hints/os390.sh +This file provides z/OS specific options to direct the build process. - make install +=head3 Shell + +A message of the form: + + (I see you are using the Korn shell. Some ksh's blow up on Configure, + mainly on older exotic systems. If yours does, try the Bourne shell + instead.) -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. +is nothing to worry about at all. + +=head3 Dynamic loading + +Dynamic loading is required if you want to use XS modules from CPAN (like +DBI (and DBD's), JSON::XS, and Text::CSV_XS) or update CORE modules from +CPAN with newer versions (like Encode) without rebuilding all of the perl +binary. + +The instructions above will create a dynamic Perl. If you do not want to +use dynamic loading, remove the -Dusedl option. +See the comments in hints/os390.sh for more information on dynamic loading. + +=head3 Optimizing + +Optimization has not been turned on yet. There may be issues if Perl +is optimized. =head2 Build Anomalies with Perl on OS/390 "Out of memory!" messages during the build of Perl are most often fixed by re building the GNU make utility for OS/390 from a source code kit. -Another memory limiting item to check is your MAXASSIZE parameter in your -'SYS1.PARMLIB(BPXPRMxx)' data set (note too that as of V2R8 address space -limits can be set on a per user ID basis in the USS segment of a RACF -profile). People have reported successful builds of Perl with MAXASSIZE -parameters as small as 503316480 (and it may be possible to build Perl -with a MAXASSIZE smaller than that). - -Within USS your /etc/profile or $HOME/.profile may limit your ulimit +Within USS your F or F<$HOME/.profile> may limit your ulimit settings. Check that the following command returns reasonable values: ulimit -a @@ -214,72 +270,30 @@ settings. Check that the following command returns reasonable values: To conserve memory you should have your compiler modules loaded into the Link Pack Area (LPA/ELPA) rather than in a link list or step lib. -If the c89 compiler complains of syntax errors during the build of the +If the 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. =head2 Testing Anomalies with Perl on OS/390 -The `make test` step runs a Perl Verification Procedure, usually before +The "make test" step runs a Perl Verification Procedure, usually before installation. You might encounter STDERR messages even during a successful -run of `make test`. Here is a guide to some of the more commonly seen +run of "make test". Here is a guide to some of the more commonly seen anomalies: -=over 4 - -=item * - -A message of the form: - - 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 - -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. - -=item * - -A message of the form: - - io/openpid...........CEE5210S The signal SIGHUP was received. - CEE5210S The signal SIGHUP was received. - CEE5210S The signal SIGHUP was received. - ok - -indicates that the t/io/openpid.t test of Perl has passed but done so -with extraneous messages on stderr from CEE. - -=item * - -A message of the form: - - 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 - -indicates a problem with the permissions on your /tmp directory within the HFS. -To correct that problem issue the command: - - chmod a+t /tmp +=head3 Out of Memory (31-bit only) -from an account with write access to the directory entry for /tmp. +Out of memory problems should not be an issue, unless you are attempting to build +a 31-bit Perl. -=item * - -Out of Memory! - -Recent perl test suite is quite memory hunrgy. In addition to the comments +If you _are_ building a 31-bit Perl, the constrained environment may mean you +need to change memory options for Perl. +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 +in your environment. Perl now has (in miniperlmain.c) a C #pragma for 31-bit only to set CEE run options, but the environment variable wins. -The C code asks for: +The 31-bit C code asks for: #pragma runopts(HEAP(2M,500K,ANYWHERE,KEEP,8K,4K) STACK(,,ANY,) ALL31(ON)) @@ -298,74 +312,20 @@ case something like: is needed to get through the test suite. +=head2 Usage Hints for Perl on z/OS -=back - -=head2 Installation Anomalies with Perl on OS/390 - -The installman script will try to run on OS/390. There will be fewer errors -if you have a roff utility installed. You can obtain GNU groff from the -Redbook SG24-5944-00 ftp site. - -=head2 Usage Hints for Perl on OS/390 - -When using perl on OS/390 please keep in mind that the EBCDIC and ASCII -character sets are different. See perlebcdic.pod for more on such character +When using Perl on z/OS please keep in mind that the EBCDIC and ASCII +character sets are different. See L for more on such character set issues. Perl builtin functions that may behave differently under EBCDIC are also mentioned in the perlport.pod document. -Open Edition (UNIX System Services) from V2R8 onward does support -#!/path/to/perl script invocation. There is a PTF available from -IBM for V2R7 that will allow shell/kernel support for #!. USS -releases prior to V2R7 did not support the #! means of script invocation. -If you are running V2R6 or earlier then see: - - head `whence perldoc` - -for an example of how to use the "eval exec" trick to ask the shell to -have Perl run your scripts on those older releases of Unix System Services. - If you are having trouble with square brackets then consider switching your rlogin or telnet client. Try to avoid older 3270 emulators and ISHELL for working with Perl on USS. -=head2 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 int() on the product of a number and a small -magnitude number is not the same as calling int() on the quotient of -that number and a large magnitude number. For example, in the following -Perl code: - - my $x = 100000.0; - my $y = int($x * 1e-5) * 1e5; # '0' - my $z = int($x / 1e+5) * 1e5; # '100000' - print "\$y is $y and \$z is $z\n"; # $y is 0 and $z is 100000 - -Although one would expect the quantities $y and $z to be the same and equal -to 100000 they will differ and instead will be 0 and 100000 respectively. +=head2 Modules and Extensions for Perl on z/OS (Static Only) -The problem can be further examined in a roughly equivalent C program: - - #include - #include - 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\n",y*1e5,z*1e5); - /* y is 0.000000e+00 and z is 1.000000e+05 (with c89) */ - } - -=head2 Modules and Extensions for Perl on OS/390 - -Pure pure (that is non xs) modules may be installed via the usual: +Pure Perl (that is non XS) modules may be installed via the usual: perl Makefile.PL make @@ -373,11 +333,11 @@ Pure pure (that is non xs) modules may be installed via the usual: make install 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 OS/390 +be the way to build XS based extensions. However, if you built perl with +static linking you can still build XS based extensions for z/OS 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: +building a static perl + XS extension boils down to: perl Makefile.PL make @@ -386,15 +346,34 @@ building a static perl + xs extension boils down to: make install make -f Makefile.aperl inst_perl MAP_TARGET=perl -In most cases people have reported better results with GNU make rather -than the system's /bin/make program, whether for plain modules or for -xs based extensions. +=head2 Running Perl on z/OS + +To run the 64-bit Dynamic Perl environment, update your PATH and LIBPATH +to include the location you installed Perl into, and then run the perl you +installed as perlV.R.M where V/R/M is the Version/Release/Modification level +of the current development level. +If you are running the ASCII/EBCDIC Bi-Modal Perl environment, you also need to +set up your ASCII/EBCDIC Bi-Modal environment variables, and ensure any Perl +source code you run is tagged appropriately as ASCII or EBCDIC using +"chtag -t -c": + +=over -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: +=item For ASCII Only: - export _C89_CCMODE=1 + export _BPXK_AUTOCVT=ON + export _CEE_RUNOPTS="FILETAG(AUTOCVT,AUTOTAG),POSIX(ON)" + export _TAG_REDIR_ERR="txt" + export _TAG_REDIR_IN="txt" + export _TAG_REDIR_OUT="txt" + +=item For ASCII or EBCDIC: + + export PATH=/usr/local/perl/ascii:$PATH + export LIBPATH=/usr/local/perl/ascii/lib:$LIBPATH + perlV.R.M args + +=back If tcsh is your login shell then use the setenv command. @@ -406,53 +385,35 @@ Thanks to Mike MacIsaac and Egon Terwedow for SG24-5944-00. Thanks to Ignasi Roca for pointing out the floating point problems. Thanks to John Goodyear for dynamic loading help. -=head1 SEE ALSO - -L, L, L, L. - - http://www-1.ibm.com/servers/eserver/zseries/zos/unix/bpxa1toy.html +Mike Fulton and Karl Williamson have provided updates for UTF8, DLL, 64-bit and +ASCII/EBCDIC Bi-Modal support - http://www.redbooks.ibm.com/abstracts/sg245944.html +=head1 OTHER SITES - http://www-1.ibm.com/servers/eserver/zseries/zos/unix/bpxa1ty1.html#opensrc +L provides documentation and tools +for building various z/OS Perl configurations and has some useful tools in the +'bin' directory you may want to use for building z/OS Perl yourself. - http://www.xray.mpe.mpg.de/mailing-lists/perl-mvs/ - - http://publibz.boulder.ibm.com:80/cgi-bin/bookmgr_OS390/BOOKS/ceea3030/ +=head1 HISTORY - http://publibz.boulder.ibm.com:80/cgi-bin/bookmgr_OS390/BOOKS/CBCUG030/ +Updated 24 December 2021 to enable initial ASCII support -=head2 Mailing list for Perl on OS/390 +Updated 03 October 2019 for perl-5.33.3+ -If you are interested in the VM/ESA, z/OS (formerly known as OS/390) -and POSIX-BC (BS2000) ports of Perl then see the perl-mvs mailing list. -To subscribe, send an empty message to perl-mvs-subscribe@perl.org. +Updated 28 November 2001 for broken URLs. -See also: +Updated 12 March 2001 to mention //'SYS1.TCPPARMS(TCPDATA)'. - http://lists.perl.org/showlist.cgi?name=perl-mvs +Updated 24 January 2001 to mention dynamic loading. -There are web archives of the mailing list at: +Updated 15 January 2001 for the 5.7.1 release of Perl. - http://www.xray.mpe.mpg.de/mailing-lists/perl-mvs/ - http://archive.develooper.com/perl-mvs@perl.org/ +Updated 12 November 2000 for the 5.7.1 release of Perl. -=head1 HISTORY +This document was podified for the 5.005_03 release of Perl 11 March 1999. This document was originally written by David Fiander for the 5.005 release of Perl. -This document was podified for the 5.005_03 release of Perl 11 March 1999. - -Updated 28 November 2001 for broken URLs. - -Updated 12 November 2000 for the 5.7.1 release of Perl. - -Updated 15 January 2001 for the 5.7.1 release of Perl. - -Updated 24 January 2001 to mention dynamic loading. - -Updated 12 March 2001 to mention //'SYS1.TCPPARMS(TCPDATA)'. - =cut