The new(er) way of controlling Unicode I/O (and other) features;
[p5sagit/p5-mst-13.2.git] / README.vms
CommitLineData
b4bc034f 1If you read this file _as_is_, just ignore the equal signs on the left.
2This file is written in the POD format (see [.POD]PERLPOD.POD;1) which is
3specially designed to be readable as is.
fb73857a 4
b4bc034f 5=head1 NAME
6
7README.vms - Configuring, building, testing, and installing perl on VMS
8
9=head1 SYNOPSIS
10
11To configure, build, test, and install perl on VMS:
12
13 @ Configure
14 mms
15 mms test
16 mms install
17
18mmk may be used in place of mms in the last three steps.
19
20=head1 DESCRIPTION
21
22=head2 Important safety tip
97abc6ad 23
3a385817 24The build and install procedures have changed significantly from the 5.004
b4bc034f 25releases! Make sure you read the "Configuring the Perl Build", "Building
26Perl", and "Installing Perl" sections of this document before you build or
e7948fac 27install. Also please note other changes in the current release by having
28a look at L<perldelta/VMS>.
97abc6ad 29
b4bc034f 30Also note that, as of Perl version 5.005 and later, an ANSI C compliant
31compiler is required to build Perl. VAX C is *not* ANSI compliant, as it
32died a natural death some time before the standard was set. Therefore
1bc81404 33VAX C will not compile Perl 5.005 or later. We are sorry about that.
3bf5f72b 34
e7948fac 35If you are stuck without Compaq (formerly DEC) C consider trying Gnu C
36instead, though there have been no recent reports of builds using Gnu C.
37There is minimal support for Compaq C++ but this support is not complete;
38if you get it working please write to the vmsperl list (for info see
39L</"Mailing Lists">).
3bf5f72b 40
b4bc034f 41
a83b6f46 42=head2 Introduction to Perl on VMS
fb73857a 43
44The VMS port of Perl is as functionally complete as any other Perl port
45(and as complete as the ports on some Unix systems). The Perl binaries
46provide all the Perl system calls that are either available under VMS or
b4bc034f 47reasonably emulated. There are some incompatibilities in process handling
48(e.g. the fork/exec model for creating subprocesses doesn't do what you
fb73857a 49might expect under Unix), mainly because VMS and Unix handle processes and
50sub-processes very differently.
51
b4bc034f 52There are still some unimplemented system functions, and of course we
fb73857a 53could use modules implementing useful VMS system services, so if you'd like
b4bc034f 54to lend a hand we'd love to have you. Join the Perl Porting Team Now!
fb73857a 55
56The current sources and build procedures have been tested on a VAX using
b4bc034f 57DEC C, and on an AXP using DEC C. If you run into problems with
1bc81404 58other compilers, please let us know. (Note: DEC C was renamed to Compaq C
59around version 6.2).
fb73857a 60
b4bc034f 61There are issues with various versions of DEC C, so if you're not running a
62relatively modern version, check the "DEC C issues" section later on in this
fb73857a 63document.
64
a83b6f46 65=head2 Other required software for Compiling Perl on VMS
b4bc034f 66
67In addition to VMS and DCL you will need two things:
fb73857a 68
b4bc034f 69=over 4
70
71=item 1 A C compiler.
72
1bc81404 73DEC (now Compaq) C or gcc for VMS (AXP or VAX).
b4bc034f 74
75=item 2 A make tool.
76
77DEC's MMS (v2.6 or later), or MadGoat's free MMS
78analog MMK (available from ftp.madgoat.com/madgoat) both work
79just fine. Gnu Make might work, but it's been so long since
80anyone's tested it that we're not sure. MMK is free though, so
81go ahead and use that.
82
83=back
84
a83b6f46 85=head2 Additional software that is optional for Perl on VMS
fb73857a 86
9f3f8d50 87You may also want to have on hand:
b4bc034f 88
89=over 4
90
91=item 1 GUNZIP/GZIP.EXE for VMS
92
93A de-compressor for *.gz and *.tgz files available from a number
58979ab1 94of web/ftp sites and is distributed on the OpenVMS Freeware CD-ROM
95from Compaq.
b4bc034f 96
9f3f8d50 97 http://www.fsf.org/order/ftp.html
adc5a9a5 98 http://www.openvms.compaq.com/freeware/
1bc81404 99 http://www.crinoid.com/utils/
b4bc034f 100
101=item 2 VMS TAR
102
103For reading and writing unix tape archives (*.tar files). Vmstar is also
58979ab1 104available from a number of web/ftp sites and is distributed on the OpenVMS
105Freeware CD-ROM from Compaq.
b4bc034f 106
9f3f8d50 107 ftp://ftp.lp.se/vms/
adc5a9a5 108 http://www.openvms.compaq.com/freeware/
b4bc034f 109
110=item 3 UNZIP.EXE for VMS
111
112A combination decompressor and archive reader/writer for *.zip files.
113Unzip is available from a number of web/ftp sites.
114
adc5a9a5 115 http://www.info-zip.org/UnZip.html
116 http://www.openvms.compaq.com/freeware/
58979ab1 117 ftp://ftp.openvms.compaq.com/
b4bc034f 118 ftp://ftp.madgoat.com/madgoat/
adc5a9a5 119 ftp://ftp.process.com/vms-freeware/
b4bc034f 120
121=item 4 MOST
122
123Most is an optional pager that is convenient to use with perldoc (unlike
124TYPE/PAGE, MOST can go forward and backwards in a document and supports
125regular expression searching). Most builds with the slang
126library on VMS. Most and slang are available from:
127
128 ftp://space.mit.edu/pub/davis/
adc5a9a5 129 ftp://ftp.process.com/vms-freeware/narnia/
b4bc034f 130
1bc81404 131=item 5 GNU PATCH and DIFFUTILS for VMS
132
133Patches to Perl are usually distributed as GNU unified or contextual diffs.
134Such patches are created by the GNU diff program (part of the diffutils
135distribution) and applied with GNU patch. VMS ports of these utilities are
136available here:
137
138 http://www.crinoid.com/utils/
adc5a9a5 139 http://www.openvms.compaq.com/freeware/
1bc81404 140
b4bc034f 141=back
142
9f3f8d50 143Please note that UNZIP and GUNZIP are not the same thing (they work with
b4bc034f 144different formats). Many of the useful files from CPAN (the Comprehensive
58979ab1 145Perl Archive Network) are in *.tar.gz or *.tgz format (this includes copies
146of the source code for perl as well as modules and scripts that you may
147wish to add later) hence you probably want to have GUNZIP.EXE and
148VMSTAR.EXE on your VMS machine.
fb73857a 149
b4bc034f 150If you want to include socket support, you'll need a TCP/IP stack and either
151DEC C, or socket libraries. See the "Socket Support (optional)" topic
152for more details.
fb73857a 153
b4bc034f 154=head1 Configuring the Perl build
fb73857a 155
97abc6ad 156To configure perl (a necessary first step), issue the command
fb73857a 157
b4bc034f 158 @ Configure
fb73857a 159
b4bc034f 160from the top of an unpacked perl source directory. You will be asked a
161series of questions, and the answers to them (along with the capabilities
162of your C compiler and network stack) will determine how perl is custom
163built for your machine.
fb73857a 164
b4bc034f 165If you have multiple C compilers installed, you'll have your choice of
166which one to use. Various older versions of DEC C had some caveats, so if
167you're using a version older than 5.2, check the "DEC C Issues" section.
fb73857a 168
b4bc034f 169If you have any symbols or logical names in your environment that may
170interfere with the build or regression testing of perl then configure.com
171will try to warn you about them. If a logical name is causing
7bb57f25 172you trouble but is in an LNM table that you do not have write access to
173then try defining your own to a harmless equivalence string in a table
174such that it is resolved before the other (e.g. if TMP is defined in the
b4bc034f 175SYSTEM table then try DEFINE TMP "NL:" or somesuch in your process table)
176otherwise simply deassign the dangerous logical names. The potentially
177troublesome logicals and symbols are:
7bb57f25 178
179 TMP "LOGICAL"
180 LIB "LOGICAL"
181 T "LOGICAL"
182 FOO "LOGICAL"
183 EXT "LOGICAL"
184 TEST "SYMBOL"
fb73857a 185
97abc6ad 186As a handy shortcut, the command:
187
b4bc034f 188 @ Configure "-des"
189
190(note the quotation marks and case) will choose reasonable defaults
191automatically (it takes DEC C over Gnu C, DEC C sockets over SOCKETSHR
1bc81404 192sockets, and either over no sockets). Some options can be given
193explicitly on the command line; the following example specifies a
194non-default location for where Perl will be installed:
195
196 @ Configure "-d" "-Dprefix=dka100:[utils.perl5.]"
197
dab31494 198Note that the installation location would be by default where you unpacked
fe05d1a7 199the source with a "_ROOT." appended. For example if you unpacked the perl
dab31494 200source into:
201
202 DKA200:[PERL-5_10_2...]
203
adc5a9a5 204Then the PERL_SETUP.COM that gets written out by CONFIGURE.COM will
dab31494 205try to DEFINE your installation PERL_ROOT to be:
206
fe05d1a7 207 DKA200:[PERL-5_10_2_ROOT.]
dab31494 208
1bc81404 209More help with configure.com is available from:
b4bc034f 210
211 @ Configure "-h"
212
213See the "Changing compile-time options (optional)" section below to learn
214even more details about how to influence the outcome of the important
215configuration step. If you find yourself reconfiguring and rebuilding
216then be sure to also follow the advice in the "Cleaning up and starting
217fresh (optional)" and the checklist of items in the "CAVEATS" sections
218below.
219
a83b6f46 220=head2 Changing compile-time options (optional) for Perl on VMS
b4bc034f 221
222Most of the user definable features of Perl are enabled or disabled in
adc5a9a5 223configure.com, which processes the hints file config_h.SH. There is
224code in there to Do The Right Thing, but that may end up being the
225wrong thing for you. Make sure you understand what you are doing since
226inappropriate changes to configure.com or config_h.SH can render perl
227unbuildable; odds are that there's nothing in there you'll need to
228change.
b4bc034f 229
230The one exception is the various *DIR install locations. Changing those
231requires changes in genconfig.pl as well. Be really careful if you need to
232change these, as they can cause some fairly subtle problems.
233
a83b6f46 234=head2 Socket Support (optional) for Perl on VMS
b4bc034f 235
236Perl includes a number of functions for IP sockets, which are available if
237you choose to compile Perl with socket support. Since IP networking is an
238optional addition to VMS, there are several different IP stacks available.
239How well integrated they are into the system depends on the stack, your
240version of VMS, and the version of your C compiler.
241
242The most portable solution uses the SOCKETSHR library. In combination with
243either UCX or NetLib, this supports all the major TCP stacks (Multinet,
244Pathways, TCPWare, UCX, and CMU) on all versions of VMS Perl runs on, with
245all the compilers on both VAX and Alpha. The socket interface is also
246consistent across versions of VMS and C compilers. It has a problem with
247UDP sockets when used with Multinet, though, so you should be aware of
248that.
249
250The other solution available is to use the socket routines built into DEC
251C. Which routines are available depend on the version of VMS you're
252running, and require proper UCX emulation by your TCP/IP vendor.
253Relatively current versions of Multinet, TCPWare, Pathway, and UCX all
254provide the required libraries--check your manuals or release notes to see
255if your version is new enough.
256
257=head1 Building Perl
258
259The configuration script will print out, at the very end, the MMS or MMK
260command you need to compile perl. Issue it (exactly as printed) to start
261the build.
97abc6ad 262
b4bc034f 263Once you issue your MMS or MMK command, sit back and wait. Perl should
264compile and link without a problem. If a problem does occur check the
265"CAVEATS" section of this document. If that does not help send some
266mail to the VMSPERL mailing list. Instructions are in the "Mailing Lists"
267section of this document.
97abc6ad 268
b4bc034f 269=head1 Testing Perl
fb73857a 270
b4bc034f 271Once Perl has built cleanly you need to test it to make sure things work.
272This step is very important since there are always things that can go wrong
273somehow and yield a dysfunctional Perl for you.
fb73857a 274
275Testing is very easy, though, as there's a full test suite in the perl
b4bc034f 276distribution. To run the tests, enter the *exact* MMS line you used to
fb73857a 277compile Perl and add the word "test" to the end, like this:
278
b4bc034f 279If the compile command was:
fb73857a 280
b4bc034f 281 MMS
fb73857a 282
b4bc034f 283then the test command ought to be:
fb73857a 284
b4bc034f 285 MMS test
fb73857a 286
b4bc034f 287MMS (or MMK) will run all the tests. This may take some time, as there are
288a lot of tests. If any tests fail, there will be a note made on-screen.
289At the end of all the tests, a summary of the tests, the number passed and
290failed, and the time taken will be displayed.
fb73857a 291
96d6186e 292The test driver invoked via MMS TEST has a DCL wrapper ([.VMS]TEST.COM) that
293downgrades privileges to NETMBX, TMPMBX for the duration of the test run,
294and then restores them to their prior state upon completion of testing.
295This is done to ensure that the tests run in a private sandbox and can do no
296harm to your system even in the unlikely event something goes badly wrong in
297one of the test scripts while running the tests from a privileged account.
298A side effect of this safety precaution is that the account used to run the
299test suite must be the owner of the directory tree in which Perl has been
300built; otherwise the manipulations of temporary files and directories
301attempted by some of the tests will fail.
302
b4bc034f 303If any tests fail, it means something is wrong with Perl. If the test suite
fb73857a 304hangs (some tests can take upwards of two or three minutes, or more if
9f3f8d50 305you're on an especially slow machine, depending on your machine speed, so
fb73857a 306don't be hasty), then the test *after* the last one displayed failed. Don't
307install Perl unless you're confident that you're OK. Regardless of how
308confident you are, make a bug report to the VMSPerl mailing list.
309
b4bc034f 310If one or more tests fail, you can get more information on the failure by
311issuing this command sequence:
fb73857a 312
b4bc034f 313 @ [.VMS]TEST .typ "" "-v" [.subdir]test.T
fb73857a 314
315where ".typ" is the file type of the Perl images you just built (if you
316didn't do anything special, use .EXE), and "[.subdir]test.T" is the test
317that failed. For example, with a normal Perl build, if the test indicated
96d6186e 318that t/op/time failed, then you'd do this:
fb73857a 319
b4bc034f 320 @ [.VMS]TEST .EXE "" "-v" [.OP]TIME.T
fb73857a 321
96d6186e 322Note that test names are reported in UNIX syntax and relative to the
323top-level build directory. When supplying them individually to the test
324driver, you can use either UNIX or VMS syntax, but you must give the path
325relative to the [.T] directory and you must also add the .T extension to the
326filename. So, for example if the test lib/Math/Trig fails, you would run:
327
328 @ [.VMS]TEST .EXE "" -"v" [-.lib.math]trig.t
329
fb73857a 330When you send in a bug report for failed tests, please include the output
331from this command, which is run from the main source directory:
332
b4bc034f 333 MCR []MINIPERL "-V"
334
335Note that -"V" really is a capital V in double quotes. This will dump out a
336couple of screens worth of configuration information, and can help us
337diagnose the problem. If (and only if) that did not work then try enclosing
338the output of:
339
340 MMS printconfig
fb73857a 341
9f3f8d50 342If (and only if) that did not work then try enclosing the output of:
343
b4bc034f 344 @ [.vms]myconfig
fb73857a 345
b4bc034f 346You may also be asked to provide your C compiler version ("CC/VERSION NL:"
347with DEC C, "gcc --version" with GNU CC). To obtain the version of MMS or
348MMK you are running try "MMS/ident" or "MMK /ident". The GNU make version
349can be identified with "make --version".
350
a83b6f46 351=head2 Cleaning up and starting fresh (optional) installing Perl on VMS
fb73857a 352
353If you need to recompile from scratch, you have to make sure you clean up
b4bc034f 354first. There is a procedure to do it--enter the *exact* MMS line you used
355to compile and add "realclean" at the end, like this:
fb73857a 356
b4bc034f 357if the compile command was:
fb73857a 358
b4bc034f 359 MMS
fb73857a 360
b4bc034f 361then the cleanup command ought to be:
fb73857a 362
b4bc034f 363 MMS realclean
fb73857a 364
b4bc034f 365If you do not do this things may behave erratically during the subsequent
366rebuild attempt. They might not, too, so it is best to be sure and do it.
fb73857a 367
b4bc034f 368=head1 Installing Perl
fb73857a 369
370There are several steps you need to take to get Perl installed and
3a385817 371running.
fb73857a 372
a3ef2c6f 373=over 4
b4bc034f 374
a3ef2c6f 375=item 1
fb73857a 376
a3ef2c6f 377Check your default file protections with
fb73857a 378
a3ef2c6f 379 SHOW PROTECTION /DEFAULT
fb73857a 380
a3ef2c6f 381and adjust if necessary with SET PROTECTION=(code)/DEFAULT.
fb73857a 382
a3ef2c6f 383=item 2
3a385817 384
1bc81404 385Decide where you want Perl to be installed (unless you have already done so
386by using the "prefix" configuration parameter -- see the example in the
387"Configuring the Perl build" section).
b4bc034f 388
1bc81404 389The DCL script PERL_SETUP.COM that is written by CONFIGURE.COM will help you
390with the definition of the PERL_ROOT and PERLSHR logical names and the PERL
391foreign command symbol. Take a look at PERL_SETUP.COM and modify it if you
392want to. The installation process will execute PERL_SETUP.COM and copy
393files to the directory tree pointed to by the PERL_ROOT logical name defined
394there, so make sure that you have write access to the parent directory of
395what will become the root of your Perl installation.
fb73857a 396
a3ef2c6f 397=item 3
b4bc034f 398
a3ef2c6f 399Run the install script via:
b4bc034f 400
a3ef2c6f 401 MMS install
b4bc034f 402
a3ef2c6f 403or
9f3f8d50 404
a3ef2c6f 405 MMK install
b4bc034f 406
a3ef2c6f 407If for some reason it complains about target INSTALL being up to date,
408throw a /FORCE switch on the MMS or MMK command.
b4bc034f 409
a3ef2c6f 410=back
411
1bc81404 412Copy PERL_SETUP.COM to a place accessible to your perl users.
413
a3ef2c6f 414For example:
fb73857a 415
a3ef2c6f 416 COPY PERL_SETUP.COM SYS$LIBRARY:
b4bc034f 417
a3ef2c6f 418If you want to have everyone on the system have access to perl
419then add a line that reads
fb73857a 420
a3ef2c6f 421 $ @sys$library:perl_setup
491527d0 422
a3ef2c6f 423to SYS$MANAGER:SYLOGIN.COM.
85988417 424
a3ef2c6f 425Two alternatives to the foreign symbol would be to install PERL into
426DCLTABLES.EXE (Check out the section "Installing Perl into DCLTABLES
427(optional)" for more information), or put the image in a
428directory that's in your DCL$PATH (if you're using VMS V6.2 or higher).
85988417 429
a3ef2c6f 430An alternative to having PERL_SETUP.COM define the PERLSHR logical name
431is to simply copy it into the system shareable library directory with:
432
433 copy perl_root:[000000]perlshr.exe sys$share:
85988417 434
a3ef2c6f 435See also the "INSTALLing images (optional)" section.
491527d0 436
a83b6f46 437=head2 Installing Perl into DCLTABLES (optional) on VMS
fb73857a 438
9ef4b0a6 439Execute the following command file to define PERL as a DCL command.
b4bc034f 440You'll need CMKRNL privilege to install the new dcltables.exe.
fb73857a 441
7bb57f25 442 $ create perl.cld
443 !
444 ! modify to reflect location of your perl.exe
445 !
446 define verb perl
447 image perl_root:[000000]perl.exe
448 cliflags (foreign)
449 $!
450 $ set command perl /table=sys$common:[syslib]dcltables.exe -
451 /output=sys$common:[syslib]dcltables.exe
452 $ install replace sys$common:[syslib]dcltables.exe
453 $ exit
fb73857a 454
a83b6f46 455=head2 INSTALLing Perl images (optional) on VMS
9f3f8d50 456
457On systems that are using perl quite a bit, and particularly those with
458minimal RAM, you can boost the performance of perl by INSTALLing it as
adc5a9a5 459a known image. PERLSHR.EXE is typically larger than 3000 blocks
9f3f8d50 460and that is a reasonably large amount of IO to load each time perl is
461invoked.
462
463 INSTALL ADD PERLSHR/SHARE
b4bc034f 464 INSTALL ADD PERL/HEADER
9f3f8d50 465
466should be enough for PERLSHR.EXE (/share implies /header and /open),
467while /HEADER should do for PERL.EXE (perl.exe is not a shared image).
468
b4bc034f 469If your code 'use's modules, check to see if there is a shareable image for
470them, too. In the base perl build, POSIX, IO, Fcntl, Opcode, SDBM_File,
e7948fac 471DCLsym, and Stdio, and other extensions all have shared images that can be
472installed /SHARE.
9f3f8d50 473
b4bc034f 474How much of a win depends on your memory situation, but if you are firing
9f3f8d50 475off perl with any regularity (like more than once every 20 seconds or so)
b4bc034f 476it is probably beneficial to INSTALL at least portions of perl.
9f3f8d50 477
478While there is code in perl to remove privileges as it runs you are advised
479to NOT INSTALL PERL.EXE with PRIVs!
fb73857a 480
dab31494 481=head2 Running h2ph to create perl header files (optional) on VMS
482
483If using DEC C or Compaq C ensure that you have extracted loose versions
484of your compiler's header or *.H files. Be sure to check the contents of:
485
486 SYS$LIBRARY:DECC$RTLDEF.TLB
487 SYS$LIBRARY:SYS$LIB_C.TLB
488 SYS$LIBRARY:SYS$STARLET_C.TLB
489
490etcetera.
491
492If using GNU cc then also check your GNU_CC:[000000...] tree for the locations
493of the GNU cc headers.
494
b4bc034f 495=head1 Reporting Bugs
fb73857a 496
497If you come across what you think might be a bug in Perl, please report
498it. There's a script in PERL_ROOT:[UTILS], perlbug, that walks you through
499the process of creating a bug report. This script includes details of your
500installation, and is very handy. Completed bug reports should go to
9f3f8d50 501perlbug@perl.com.
fb73857a 502
b4bc034f 503=head1 CAVEATS
fb73857a 504
505Probably the single biggest gotcha in compiling Perl is giving the wrong
b4bc034f 506switches to MMS/MMK when you build. Use *exactly* what the configure.com
507script prints!
508
509The next big gotcha is directory depth. Perl can create directories four,
510five, or even six levels deep during the build, so you don't have to be
dab31494 511too deep to start to hit the RMS 8 level limit (for ODS 2 volumes which were
512common on versions of VMS prior to V7.2 and even with V7.2 on the VAX).
513It is best to do:
b4bc034f 514
515 DEFINE/TRANS=(CONC,TERM) PERLSRC "disk:[dir.dir.dir.perldir.]"
516 SET DEFAULT PERLSRC:[000000]
517
518before building in cases where you have to unpack the distribution so deep
519(note the trailing period in the definition of PERLSRC). Perl modules
520from CPAN can be just as bad (or worse), so watch out for them, too. Perl's
521configuration script will warn if it thinks you are too deep (at least on
522a VAX or on Alpha versions of VMS prior to 7.2). But MakeMaker will not
523warn you if you start out building a module too deep in a directory.
524
525Be sure that the process that you use to build perl has a PGFLQ greater
526than 100000. Be sure to have a correct local time zone to UTC offset
527defined (in seconds) in the logical name SYS$TIMEZONE_DIFFERENTIAL before
528running the regression test suite. The SYS$MANAGER:UTC$CONFIGURE_TDF.COM
529procedure will help you set that logical for your system but may require
530system privileges. For example, a location 5 hours west of UTC (such as
531the US East coast while not on daylight savings time) would have:
532
533 DEFINE SYS$TIMEZONE_DIFFERENTIAL "-18000"
534
535A final thing that causes trouble is leftover pieces from a failed
536build. If things go wrong make sure you do a "(MMK|MMS|make) realclean"
fb73857a 537before you rebuild.
538
a83b6f46 539=head2 DEC C issues with Perl on VMS
fb73857a 540
b4bc034f 541Note to DEC C users: Some early versions (pre-5.2, some pre-4. If you're DEC
c54e8273 542C 5.x or higher, with current patches if any, you're fine) of the DECCRTL
fb73857a 543contained a few bugs which affect Perl performance:
b4bc034f 544
545=over 4
546
547=item - pipes
548
549Newlines are lost on I/O through pipes, causing lines to run together.
550This shows up as RMS RTB errors when reading from a pipe. You can
551work around this by having one process write data to a file, and
552then having the other read the file, instead of the pipe. This is
553fixed in version 4 of DEC C.
554
555=item - modf()
556
557The modf() routine returns a non-integral value for some values above
558INT_MAX; the Perl "int" operator will return a non-integral value in
559these cases. This is fixed in version 4 of DEC C.
560
561=item - ALPACRT ECO
562
563On the AXP, if SYSNAM privilege is enabled, the CRTL chdir() routine
564changes the process default device and directory permanently, even
565though the call specified that the change should not persist after
566Perl exited. This is fixed by DEC CSC patch ALPACRT04_061 or later.
567See also:
568
172b4273 569 http://ftp.support.compaq.com/patches/.new/openvms.shtml
b4bc034f 570
571=back
572
573Please note that in later versions "DEC C" may also be known as
574"Compaq C".
575
a83b6f46 576=head2 GNU issues with Perl on VMS
b4bc034f 577
578It has been a while since the GNU utilities such as GCC or GNU make
579were used to build perl on VMS. Hence they may require a great deal
580of source code modification to work again.
581
582 http://slacvx.slac.stanford.edu/HELP/GCC
583 http://www.progis.de/
b4bc034f 584 http://www.lp.se/products/gnu.html
585
e7948fac 586=head2 Floating Point Considerations
587
588Prior to 5.8.0, Perl simply accepted the default floating point options of the
589C compiler, namely representing doubles with D_FLOAT on VAX and G_FLOAT on
590Alpha. Single precision floating point values are represented in F_FLOAT
591format when either D_FLOAT or G_FLOAT is in use for doubles. Beginning with
5925.8.0, Alpha builds now use IEEE floating point formats by default, which in
593VMS parlance are S_FLOAT for singles and T_FLOAT for doubles. IEEE is not
594available on VAX, so F_FLOAT and D_FLOAT remain the defaults for singles and
595doubles respectively. The available non-default options are G_FLOAT on VAX
596and D_FLOAT or G_FLOAT on Alpha.
597
598The use of IEEE on Alpha introduces NaN, infinity, and denormalization
599capabilities not available with D_FLOAT and G_FLOAT. When using one of those
600non-IEEE formats, silent underflow and overflow are emulated in the conversion
601of strings to numbers, but it is preferable to get the real thing by using
602IEEE where possible.
603
604Regardless of what floating point format you consider preferable, be aware
605that the choice may have an impact on compatibility with external libraries,
606such as database interfaces, and with existing data, such as data created with
607the C<pack> function and written to disk, or data stored via the Storable
608extension. For example, a C<pack("d", $foo)")> will create a D_FLOAT,
609G_FLOAT, or T_FLOAT depending on what your Perl was configured with. When
610written to disk, the value can only be retrieved later by a Perl configured
611with the same floating point option that was in effect when it was created.
612
613To obtain a non-IEEE build on Alpha, simply answer no to the "Use IEEE math?"
614question during the configuration. To obtain an option different from the C
615compiler default on either VAX or Alpha, put in the option that you want in
616answer to the "Any additional cc flags?" question. For example, to obtain a
617G_FLOAT build on VAX, put in C</FLOAT=G_FLOAT>.
618
49fd6f17 619=head2 Multinet issues with Perl on VMS
620
621Prior to the release of Perl 5.8.0 it was noted that the regression
622test for lib/Net/hostent (in file [.lib.Net]hostent.t) will fail owing
623to problems with the hostent structure returned by C calls to either
624gethostbyname() or gethostbyaddr() using DEC or Compaq C with a
625Multinet TCP/IP stack. The problem was noted in Multinet 4.3A
626using either Compaq C 6.5 or DEC C 6.0, and with Multinet 4.2A
627using DEC C 5.2, but could easily affect other versions of Multinet.
c2a352b2 628Process Software Inc. has acknowledged a bug in the Multinet version
629of UCX$IPC_SHR and has provided an ECO for it. The ECO is called
630UCX_LIBRARY_EMULATION-010_A044 and is available from:
49fd6f17 631
632 http://www.multinet.process.com/eco.html
633
c2a352b2 634As of this writing, the ECO is only available for Multinet versions
6354.3A and later. You may determine the version of Multinet that you
636are running using the command:
49fd6f17 637
638 multinet show /version
639
640from the DCL command prompt.
641
c2a352b2 642If the ECO is unavailable for your version of Multinet and you are
643unable to upgrade, you might try using Perl programming constructs
644such as:
49fd6f17 645
646 $address = substr($gethostbyname_addr,0,4);
647
648to temporarily work around the problem, or if you are brave
649and do not mind the possibility of breaking IPv6 addresses,
650you might modify the pp_sys.c file to add an ad-hoc correction
651like so:
652
653
654 --- pp_sys.c;1 Thu May 30 14:42:17 2002
655 +++ pp_sys.c Thu May 30 12:54:02 2002
656 @@ -4684,6 +4684,10 @@
657 }
658 #endif
659
660 + if (hent) {
661 + hent->h_length = 4;
662 + }
663 +
664 if (GIMME != G_ARRAY) {
665 PUSHs(sv = sv_newmortal());
666 if (hent) {
667
668then re-compile and re-test your perl. After the installation
669of the Multinet ECO you ought to back out any such changes though.
670
b4bc034f 671=head1 Mailing Lists
672
673There are several mailing lists available to the Perl porter. For VMS
fb73857a 674specific issues (including both Perl questions and installation problems)
b4bc034f 675there is the VMSPERL mailing list. It is usually a low-volume (10-12
fb73857a 676messages a week) mailing list.
677
1bc81404 678To subscribe, send a mail message to VMSPERL-SUBSCRIBE@PERL.ORG. The VMSPERL
679mailing list address is VMSPERL@PERL.ORG. Any mail sent there gets echoed
680to all subscribers of the list. There is a searchable archive of the list
681on the web at:
b4bc034f 682
683 http://www.xray.mpe.mpg.de/mailing-lists/vmsperl/
a83b6f46 684
1bc81404 685To unsubscribe from VMSPERL send a message to VMSPERL-UNSUBSCRIBE@PERL.ORG.
686Be sure to do so from the subscribed account that you are canceling.
b4bc034f 687
a83b6f46 688=head2 Web sites for Perl on VMS
b4bc034f 689
690Vmsperl pages on the web include:
691
692 http://www.sidhe.org/vmsperl/index.html
1bc81404 693 http://www.crinoid.com/
b4bc034f 694 http://duphy4.physics.drexel.edu/pub/cgi_info.htmlx
468f45d5 695 http://www.cpan.org/modules/by-module/VMS/
60d9c7be 696 http://www.xray.mpe.mpg.de/mailing-lists/vmsperl/
b4bc034f 697 http://www.best.com/~pvhp/vms/
adc5a9a5 698 http://www-ang.kfunigraz.ac.at/~binder/perl.html
60d9c7be 699 http://lists.perl.org/showlist.cgi?name=vmsperl
700 http://archive.develooper.com/vmsperl@perl.org/
adc5a9a5 701 http://www.openvms.compaq.com/openvms/products/ips/apache/csws_modperl.html
fb73857a 702
b4bc034f 703=head1 SEE ALSO
704
705Perl information for users and programmers about the port of perl to VMS is
706available from the [.VMS]PERLVMS.POD file that gets installed as L<perlvms>.
707For administrators the perlvms document also includes a detailed discussion
708of extending vmsperl with CPAN modules after Perl has been installed.
709
710=head1 AUTHORS
711
adc5a9a5 712Revised 10-October-2001 by Craig Berry craigberry@mac.com.
1bc81404 713Revised 25-February-2000 by Peter Prymmer pvhp@best.com.
714Revised 27-October-1999 by Craig Berry craigberry@mac.com.
b4bc034f 715Revised 01-March-1999 by Dan Sugalski dan@sidhe.org.
716Originally by Charles Bailey bailey@newman.upenn.edu.
717
718=head1 ACKNOWLEDGEMENTS
fb73857a 719
720A real big thanks needs to go to Charles Bailey
b4bc034f 721bailey@newman.upenn.edu, who is ultimately responsible for Perl 5.004
fb73857a 722running on VMS. Without him, nothing the rest of us have done would be at
723all important.
724
725There are, of course, far too many people involved in the porting and testing
726of Perl to mention everyone who deserves it, so please forgive us if we've
727missed someone. That said, special thanks are due to the following:
b4bc034f 728
729 Tim Adye T.J.Adye@rl.ac.uk
fb73857a 730 for the VMS emulations of getpw*()
b4bc034f 731 David Denholm denholm@conmat.phys.soton.ac.uk
fb73857a 732 for extensive testing and provision of pipe and SocketShr code,
b4bc034f 733 Mark Pizzolato mark@infocomm.com
fb73857a 734 for the getredirection() code
b4bc034f 735 Rich Salz rsalz@bbn.com
fb73857a 736 for readdir() and related routines
b4bc034f 737 Peter Prymmer pvhp@best.com
fb73857a 738 for extensive testing, as well as development work on
739 configuration and documentation for VMS Perl,
b4bc034f 740 Dan Sugalski dan@sidhe.org
fb73857a 741 for extensive contributions to recent version support,
742 development of VMS-specific extensions, and dissemination
743 of information about VMS Perl,
744 the Stanford Synchrotron Radiation Laboratory and the
745 Laboratory of Nuclear Studies at Cornell University for
9f3f8d50 746 the opportunity to test and develop for the AXP,
a3ef2c6f 747 John Hasstedt John.Hasstedt@sunysb.edu
748 for VAX VMS V7.2 support
b4bc034f 749
fb73857a 750and to the entire VMSperl group for useful advice and suggestions. In
751addition the perl5-porters deserve credit for their creativity and
752willingness to work with the VMS newcomers. Finally, the greatest debt of
b4bc034f 753gratitude is due to Larry Wall larry@wall.org, for having the ideas which
fb73857a 754have made our sleepless nights possible.
755
756Thanks,
757The VMSperl group
b4bc034f 758
759=cut
760