perlos390 - building and installing Perl for OS/390 and z/OS at Linux.org

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PERLOS390(1) Perl Programmers Reference Guide PERLOS390(1)

NAME
perlos390 - building and installing Perl for OS/390 and z/OS

SYNOPSIS
This document will help you Configure, build, test and install Perl on OS/390 (aka z/OS) Unix System Services.

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.

You may need to carry out some system configuration tasks before running the Configure script for Perl.

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.ibm.com/servers/eserver/zseries/zos/unix/bpxa1toy.html

Unpacking Perl distribution on OS/390
If using ftp remember to transfer the distribution in binary format.

Gunzip/gzip for OS/390 is discussed at:

http://www.ibm.com/servers/eserver/zseries/zos/unix/bpxa1ty1.html

to extract an ASCII tar archive on OS/390, try this:

pax -o to=IBM-1047,from=ISO8859-1 -r < latest.tar

zcat latest.tar.Z | pax -o to=IBM-1047,from=ISO8859-1 -r

If you get lots of errors of the form

tar: FSUM7171 ...: cannot set uid/gid: EDC5139I Operation not permitted.

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

rm -rf perl-...

and then use pax.

Setup and utilities for Perl on OS/390
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:

cp /samples/yyparse.c /etc

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.

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 "Tools".

Some people have reported encountering "Out of memory!" errors while trying to build Perl using GNU make
You might also want to have GNU groff for OS/390 installed before running the "make install" step for Perl.

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:

#define SO_REUSEPORT 0x0200 /* allow local address & port
reuse */ /

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.

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).

Configure Perl on OS/390
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:

· 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.)

is nothing to worry about at all.

· 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.

· 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:

CEE3501S The module libperl.dll was not found.
From entry point __dllstaticinit at compile unit offset +00000194 at

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.

· 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.

· 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

make install

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.

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 settings. Check that the following
command returns reasonable values:

ulimit -a

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 Socket extension then be sure to fix
the syntax error in the system header /usr/include/sys/socket.h.

Testing Anomalies with Perl on OS/390
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 anomalies:

· 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.

· 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

The important parts of that are the second argument (the increment) to HEAP, and allowing the stack to be
"Above the (16M) line". If the heap increment is too small then when perl (for example loading
unicode/Name.pl) tries to create a "big" (400K+) string it cannot fit in a single segment and you get "Out
of Memory!" - even if there is still plenty of memory available.

A related issue is use with perl's malloc. Perl's malloc uses "sbrk()" to get memory, and "sbrk()" is
limited to the first allocation so in this case something like:

HEAP(8M,500K,ANYWHERE,KEEP,8K,4K)

is needed to get through the test suite.

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.

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 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.

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.

The problem can be further examined in a roughly equivalent C program:

#include <stdio.h>
#include <math.h>
main()
{
double r1,r2;
double x = 100000.0;

perl Makefile.PL
make
make test
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 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:

perl Makefile.PL
make
make perl
make test
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.

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:

export _C89_CCMODE=1

If tcsh is your login shell then use the setenv command.

AUTHORS
David Fiander and Peter Prymmer with thanks to Dennis Longnecker and William Raffloer for valuable reports,
LPAR and PTF feedback. 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.

SEE ALSO
INSTALL, perlport, perlebcdic, ExtUtils::MakeMaker.

http://www.ibm.com/servers/eserver/zseries/zos/unix/bpxa1toy.html

http://www.redbooks.ibm.com/redbooks/SG245944.html

http://www.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/

Mailing list for Perl on OS/390
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 [email protected].