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c07a80fd 1Last revised: 19-Jan-1996 by Charles Bailey
a0d0e21e 2
748a9306 3The VMS port of Perl is still under development. At this time, the Perl
4binaries built under VMS handle internal operations properly, for the most
5part, as well as most of the system calls which have close equivalents under
6VMS. There are still some incompatibilities in process handling (e.g the
7fork/exec model for creating subprocesses doesn't do what you might expect
8under Unix), and there remain some file handling differences from Unix. Over
9the longer term, we'll try to get many of the useful VMS system services
10integrated as well, depending on time and people available. Of course, if
11you'd like to add something yourself, or join the porting team, we'd love to
12have you!
14The current sources and build procedures have been tested on a VAX using VAXC
15and DECC, and on an AXP using DECC. If you run into problems with other
16compilers, please let us know.
a0d0e21e 17
18Note to DECC users: Some early versions of the DECCRTL contained a few bugs
19which affect Perl performance:
20 - Newlines are lost on I/O through pipes, causing lines to run together.
21 This shows up as RMS RTB errors when reading from a pipe. You can
22 work around this by having one process write data to a file, and
23 then having the other read the file, instead of the pipe. This is
24 fixed in version 4 of DECC.
25 - The modf() routine returns a non-integral value for some values above
26 INT_MAX; the Perl "int" operator will return a non-integral value in
27 these cases. This is fixed in version 4 of DECC.
28 - On the AXP, if SYSNAM privilege is enabled, the CRTL chdir() routine
29 changes the process default device and directory permanently, even
30 though the call specified that the change should not persist after
31 Perl exited. This is fixed by DEC CSC patch AXPACRT04_061.
33* Other software required
35At the moment, in addition to basic VMS, you'll need two things:
36 - a C compiler: VAXC, DECC, or gcc for the VAX; DECC for the AXP
37 - a make tool: DEC's MMS (version 2.6 or later) or the free analog MMK
38 (available from, or a standard make utility (e.g. GNU make,
39 also available from
40In addition, you may include socket support if you have an IP stack running
41on your system. See the topic "Socket support" for more information.
43* Socket support
45Perl includes a number of IP socket routines among its builtin functions,
46which are available if you choose to compile Perl with socket support. Since
a0d0e21e 47IP networking is an optional addition to VMS, there are several different IP
48stacks available, so it's difficult to automate the process of building Perl
49with socket support in a way which will work on all systems.
a0d0e21e 50
748a9306 51By default, Perl is built without IP socket support. If you define the macro
c07a80fd 52SOCKET when invoking MMK, however, socket support will be included. As
748a9306 53distributed, Perl for VMS includes support for the SOCKETSHR socket library,
a0d0e21e 54which is layered on MadGoat software's vendor-independent NETLIB interface.
748a9306 55This provides support for all socket calls used by Perl except the
4633a7c4 56[g|s]etnet*() routines, which are replaced for the moment by stubs which
748a9306 57generate a fatal error if a Perl script attempts to call one of these routines.
58Both SOCKETSHR and NETLIB are available from MadGoat ftp sites, such as or
61You can link Perl directly to your TCP/IP stack's library, *as long as* it
62supplies shims for stdio routines which will properly handle both sockets and
63normal file descriptors. This is necessary because Perl does not distinguish
64between the two, and will try to make normal stdio calls such as read() and
65getc() on socket file descriptors. If you'd like to link Perl directly to
66your IP stack, then make the following changes:
67 - In Descrip.MMS, locate the section beginning with .ifdef SOCKET, and
68 change the SOCKLIB macro so that it translates to the filespec of your
69 IP stack's socket library. This will be added to the RTL options file.
70 - Edit the file SockAdapt.H in the [.VMS] subdirectory so that it
eacfb5f1 71 includes the Socket.H, In.H, Inet.H, NetDb.H, and, if necessary,
72 Errno.H header files for your IP stack, or so that it declares the
73 standard TCP/IP constants and data structures appropriately. (See
74 the distributed copy of SockAdapt.H for a collection of the structures
75 needed by Perl itself, and [.ext.Socket]Socket.xs for a list of the
76 constants used by the Socket extension, if you elect to built it.)
77 You should also define any logical names necessary for your C compiler
78 to find these files before invoking MM[KS] to build Perl.
79 - Edit the file SockAdapt.C in the [.VMS] subdirectory so that it
80 contains routines which substitute for any IP library routines
748a9306 81 required by Perl which your IP stack does not provide. This may
a0d0e21e 82 require a little trial and error; we'll try to compile a complete
748a9306 83 list soon of socket routines required by Perl.
a0d0e21e 84
4633a7c4 85
748a9306 86* Building Perl under VMS
a0d0e21e 87
748a9306 88Since you're reading this, presumably you've unpacked the Perl distribution
89into its directory tree, in which you will find a [.vms] subdirectory below
90the directory in which this file is found. If this isn't the case, then you'll
91need to unpack the distribution properly, or manually edit Descrip.MMS or
748a9306 92the VMS Makefile to alter directory paths as necessary. (I'd advise using the
93`normal' directory tree, at least for the first time through.) This
94subdirectory contains several files, among which are the following:
eacfb5f1 95 Config.VMS - A template Config.H set up for VMS.
96 Descrip.MMS - The MMS/MMK dependency file for building Perl
97 GenConfig.Pl - A Perl script to generate Config.SH retrospectively
98 from Config.VMS, since the Configure shell script which
99 normally generates Config.SH doesn't run under VMS.
100 GenOpt.Com - A little DCL procedure used to write some linker options
101 files, since not all make utilities can do this easily.
748a9306 102 Gen_ShrFls.Pl - A Perl script which generates linker options files and
a0d0e21e 103 MACRO declarations for PerlShr.Exe.
eacfb5f1 104 Makefile - The make dependency file for building Perl
748a9306 105 MMS2Make.Pl - A Perl script used to generate Makefile from Descrip.MMS
106 PerlVMS.pod - Documentation for VMS-specific behavior of Perl
107 Perly_[CH].VMS - Versions of the byacc output from Perl's grammar,
108 modified to include VMS-specific C compiler options
109 SockAdapt.[CH] - C source code used to integrate VMS TCP/IP support
110 Test.Com - DCL driver for Perl regression tests
111 VMSish.H - C header file containing VMS-specific definitions
112 VMS.C - C source code for VMS-specific routines
113 VMS_Yfix.Pl - Perl script to convert Perly.[CH] to Perly_[CH].VMS
114 WriteMain.Pl - Perl script to generate Perlmain.C
115The [.Ext...] directories contain VMS-specific extensions distributed with
116Perl. There may also be other files in [.VMS...] pertaining to features under
117development; for the most part, you can ignore them. Note that packages in
118[.ext.*] are not built with Perl by default; you build the ones you want
119once the basic Perl build is complete (see the perlvms docs for instructions
120on building extensions.)
a0d0e21e 121
748a9306 122Config.VMS and Decrip.MMS/Makefile are set up to build a version of Perl which
123includes all features known to work when this release was assembled. If you
124have code at your site which would support additional features (e.g. emulation
125of Unix system calls), feel free to make the appropriate changes to these
748a9306 126files. (Note: Do not use or edit config.h in the main Perl source directory;
a0d0e21e 127it is superseded by the current Config.VMS during the build.) You may also
748a9306 128wish to make site-specific changes to Descrip.MMS or Makefile to reflect local
129conventions for naming of files, etc.
131There are several pieces of system-specific information which become part of
132the Perl Config extension. Under VMS, the data for Config are generated by the
133script GenConfig.Pl in the [.VMS] subdirectory. It tries to ascertain the
134necessary information from various files, or from the system itself, and
135generally does the right thing. There is a list of hard-coded values at the
136end of this script which specifies items that are correct for most VMS systems,
137but may be incorrect for you, if your site is set up in an unusual fashion. If
138you're familiar with Perl's Config extension, feel free to edit these values as
139necessary. If this doesn't mean much to you, don't worry -- the information is
140probably correct, and even if it's not, none of these parameters affect your
141ability to build or run Perl. You'll only get the wrong answer if you ask for
142it specifically from Config.
144Examine the information at the beginning of Descrip.MMS for information about
748a9306 145specifying alternate C compilers or building a version of Perl with debugging
a0d0e21e 146support. For instance, if you want to use DECC, you'll need to include the
c07a80fd 147/macro="decc=1" qualifier to MMK (If you're using make, these options are not
148supported.) If you're on an AXP system, define the macro __AXP__ (MMK does
149this for you), and DECC will automatically be selected.
151To start the build, set default to the main source directory. Since
152Descrip.MMS assumes that VMS commands have their usual meaning, and makes use
153of command-line macros, you may want to be certain that you haven't defined DCL
154symbols which would interfere with the build. Then, if you are using MMS or
155MMK, say
a0d0e21e 156$ MMS/Descrip=[.VMS] ! or MMK
157(N.B. If you are using MMS, you must use version 2.6 or later; a bug in
158earlier versions produces malformed cc command lines.) If you are using a
159version of make, say
160$ Make -f [.VMS]Makefile
161Note that the Makefile doesn't support conditional compilation, is
a0d0e21e 162set up to use VAXC on a VAX, and does not include socket support. You can
163either edit the Makefile by hand, using Descrip.MMS as a guide, or use the
164Makefile to build Miniperl.Exe, and then run the Perl script,
a0d0e21e 165found in the [.VMS] subdirectory, to generate a new Makefile with the options
166appropriate to your site.
168If you are using MM[SK], and you decide to rebuild Perl with a different set
169of parameters (e.g. changing the C compiler, or adding socket support), be
170sure to say
171$ MMK/Descrip=[.VMS] realclean
172first, in order to remove files generated during the previous build. If
173you omit this step, you risk ending up with a copy of Perl which
174composed partially of old files and partially of new ones, which may lead
175to strange effects when you try to run Perl.
a0d0e21e 176
177A bug in some early versions of the DECC RTL on the AXP causes newlines
178to be lost when writing to a pipe. A different bug in some patched versions
179of DECC 4.0 for VAX can also scramble preprocessor output. Finally, gcc 2.7.2
180has yet another preprocessor bug, which causes line breaks to be inserted
181into the output at inopportune times. Each of these bugs causes
182to fail, since it can't parse the preprocessor output to identify global
183variables and routines. This problem is generally manifested as missing
184global symbols when linking PerlShr.Exe or Perl.Exe. You can work around
185it by defining the macro PIPES_BROKEN when you invoke MMS or MMK.
188This will build the following files:
189 Miniperl.Exe - a stand-alone version of without any extensions.
748a9306 190 Miniperl has all the intrinsic capabilities of Perl,
191 but cannot make use of the DynaLoader or any
192 extensions which use XS code.
748a9306 193 PerlShr.Exe - a shareable image containing most of Perl's internal
194 routines and global variables. Perl.Exe is linked to
195 this image, as are all dynamic extensions, so everyone's
196 using the same set of global variables and routines.
748a9306 197 Perl.Exe - the main Perl executable image. It's contains the
198 main() routine, plus code for any statically linked
199 extensions.
200 PerlShr_Attr.Opt - A linker options file which specifies psect attributes
201 matching those in PerlShr.Exe. It should be used when
202 linking images against PerlShr.Exe
203 PerlShr_Bld.Opt - A linker options file which specifies various things
204 used to build PerlShr.Exe. It should be used when
205 rebuilding PerlShr.Exe via MakeMaker-produced
206 Descrip.MMS files for static extensions.
207 c2ph - Perl program which generates template code to access
208 C struct members from Perl.
209 h2ph - Perl program which generates template code to access
210 #defined constants in a C header file from Perl,
211 using the "old-style" interface. (Largely supplanted
212 by h2xs.)
213 h2xs - Perl program which generates template files for creating
214 XSUB extensions, optionally beginning with the #defined
215 constants in a C header file.
2114d1da 216 [.lib.pod]perldoc - A Perl program which locates and displays documentation
c07a80fd 217 for Perl and its extensions.
218 [.Lib] - the Perl extension which saves configuration information
219 about Perl and your system.
eacfb5f1 220 [.Lib] - The Perl extension which performs dynamic linking of
a0d0e21e 221 shareable images for extensions.
222 Several subdirectories under [.Lib] containing preprocessed files or
223 site-specific files.
224There are, of course, a number of other files created for use during the build.
225Once you've got the binaries built, you may wish to `build' the `tidy' or
226`clean' targets to remove extra files.
228If you run into problems during the build, you can get help from the VMSPerl
229or perl5-porters mailing lists (see below). When you report the problem,
230please include the following information:
231 - The version of Perl you're trying to build. Please include any
232 "letter" patchlevel, in addition to the version number. If the
233 build successfully created Miniperl.Exe, you can check this by
234 saying '$ MCR Sys$Disk:[]Miniperl -v'. Also, please mention
235 where you obtained the distribution kit; in particular, note
236 whether you were using a basic Perl kit or the VMS test kit
237 (see below).
238 - The exact command you issued to build Perl.
239 - A copy of all error messages which were generated during the build.
240 Please include enough of the build log to establish the context of
241 the error messages.
242 - A summary of your configuration. If the build progressed far enough
243 to generate Miniperl.Exe and [.Lib], you can obtain this
244 by saying '$ MCR Sys$Disk:[]Miniperl "-V"' (note the "" around -V).
245 If not, then you can say '$ MMK/Descrip=[.VMS] printconfig' to
246 produce the summary.
247This may sound like a lot of information to send, but it'll often make
248it easier for someone to spot the problem, instead of having to give
249a spectrum of possibilities.
a0d0e21e 252
748a9306 253* Installing Perl once it's built
255Once the build is complete, you'll need to do the following:
256 - Put PerlShr.Exe in a common directory, and make it world-readable.
257 If you place it in a location other than Sys$Share, you'll need to
258 define the logical name PerlShr to point to the image. (If you're
259 installing on a VMScluster, be sure that each node is using the
260 copy of PerlShr you expect [e.g. if you put PerlShr.Exe in Sys$Share,
261 do they all share Sys$Share?]).
eacfb5f1 262 - Put Perl.Exe in a common directory, and make it world-executable.
748a9306 263 - Define a foreign command to invoke Perl, using a statement like
a0d0e21e 264 $ Perl == "$dev:[dir]Perl.Exe"
748a9306 265 - Create a world-readable directory tree for Perl library modules,
a0d0e21e 266 scripts, and what-have-you, and define PERL_ROOT as a rooted logical
267 name pointing to the top of this tree (i.e. if your Perl files were
268 going to live in DKA1:[Util.Perl5...], then you should
269 $ Define/Translation=Concealed Perl_Root DKA1:[Util.Perl5.]
270 (Be careful to follow the rules for rooted logical names; in particular,
271 remember that a rooted logical name cannot have as its device portion
272 another rooted logical name - you've got to supply the actual device name
273 and directory path to the root directory.)
274 - Place the files from the [.lib...] directory tree in the distribution
275 package into a [.lib...] directory tree off the root directory described
276 above.
748a9306 277 - Most of the Perl documentation lives in the [.pod] subdirectory, and
278 is written in a simple markup format which can be easily read. In this
279 directory as well are pod2man and pod2html translators to reformat the
280 docs for common display engines; a pod2hlp translator is under development.
281 These files are copied to [.lib.pod] during the installation.
282 - Define a foreign command to execute perldoc, such as
283 $ Perldoc == "''Perl' Perl_Root:[lib.pod]Perldoc -t"
284 This will allow users to retrieve documentation using Perldoc. For
285 more details, say "perldoc perldoc".
eacfb5f1 286That's it.
a0d0e21e 287
288If you run into a bug in Perl, please submit a bug report. The PerlBug
289program, found in the [.lib] directory, will walk you through the process
290of assembling the necessary information into a bug report, and sending
291of to the Perl bug reporting address,
293* For more information
748a9306 295If you're interested in more information on Perl in general, consult the Usenet
296newsgroups comp.lang.perl.announce and comp.lang.perl.misc. The FAQ for these
297groups provides pointers to other online sources of information, as well as
298books describing Perl in depth.
a0d0e21e 299
748a9306 300If you're interested in up-to-date information on Perl development and
a0d0e21e 301internals, you might want to subscribe to the perl5-porters mailing list. You
748a9306 302can do this by sending a message to, containing
a0d0e21e 303the single line
16d20bd9 304subscribe perl5-porters
2114d1da 305This is a high-volume list at the moment (>50 messages/day).
a0d0e21e 306
307If you're interested in ongoing information about the VMS port, you can
308subscribe to the VMSperl mailing list by sending a request to
LW (it's to a human, not a list server - this is a small
310operation at the moment). And, as always, we welcome any help or code you'd
311like to offer - you can send mail to or directly to
312the VMSperl list at
314Finally, if you'd like to try out the latest changes to VMS Perl, you can
315retrieve a test distribution kit by anonymous ftp from, in
316the file [.perl5], where "ppp" is the current Perl
317patchlevel, and "yymmddx" is a sequence number indicating the date that
318particular kit was assembled. In order to make retrieval convenient, this
319kit is also available by the name Perl5_VMSTest.Zip. These test kits contain
320"unofficial" patches from the perl5-porters group, test patches for important
321bugs, and VMS-specific fixes and improvements which have occurred since the
322last Perl release. Most of these changes will be incorporated in the next
323release of Perl, but until Larry Wall's looked at them and said they're OK,
324none of them should be considered official.
4633a7c4 325
748a9306 326Good luck using Perl. Please let us know how it works for you - we can't
327guarantee that we'll be able to fix bugs quickly, but we'll try, and we'd
328certainly like to know they're out there.
331* Acknowledgements
333There are, of course, far too many people involved in the porting and testing
748a9306 334of Perl to mention everyone who deserves it, so please forgive us if we've
a0d0e21e 335missed someone. That said, special thanks are due to the following:
336 Tim Adye <>
337 for the VMS emulations of getpw*()
338 David Denholm <>
339 for extensive testing and provision of pipe and SocketShr code,
340 Mark Pizzolato <>
341 for the getredirection() code
342 Rich Salz <>
343 for readdir() and related routines
344 Richard Dyson <> and
345 Kent Covert <>
346 for additional testing on the AXP.
347and to the entire VMSperl group for useful advice and suggestions. In addition
348the perl5-porters, especially Andy Dougherty <>
349and Tim Bunce <>, deserve credit for their creativity and
350willingness to work with the VMS newcomers. Finally, the greatest debt of
c07a80fd 351gratitude is due to Larry Wall <>, for having the ideas which
352have made our sleepless nights possible.
355The VMSperl group