1 Last revised: 12-Jun-1995 by Charles Bailey bailey@genetics.upenn.edu
3 The VMS port of Perl is still under development. At this time, the Perl
4 binaries built under VMS handle internal operations properly, for the most
5 part, as well as most of the system calls which have close equivalents under
6 VMS. There are still some incompatibilities in process handling (e.g the
7 fork/exec model for creating subprocesses doesn't do what you might expect
8 under Unix), and there remain some file handling differences from Unix. Over
9 the longer term, we'll try to get many of the useful VMS system services
10 integrated as well, depending on time and people available. Of course, if
11 you'd like to add something yourself, or join the porting team, we'd love to
14 The current sources and build procedures have been tested on a VAX using VAXC
15 and on an AXP using DECC. If you run into problems with other compilers,
18 Note to DECC users: Some early versions of the DECCRTL contained a few bugs
19 which 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
35 At 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 or the free analog MMK (available from ftp.spc.edu)
38 or a standard make utility (e.g. GNU make, also available from
40 In addition, you may include socket support if you have a IP stack running
41 on your system. See the topic "Socket support" for more information.
45 Perl includes a number of IP socket routines among its builtin functions,
46 which are available if you choose to compile Perl with socket support. Since
47 IP networking is an optional addition to VMS, there are several different IP
48 stacks available, it's difficult to automate the process of building Perl with
49 socket support in a way which will work on all systems.
51 By default, Perl is built without IP socket support. If you define the macro
52 SOCKET when invoking MMS, however, socket support will be included. As
53 distributed, Perl for VMS includes support for the SOCKETSHR socket library,
54 which is layered on MadGoat software's vendor-independent NETLIB interface.
55 This provides support for all socket calls used by Perl except the
56 [g|s]etnet*() routines, which are replaced for the moment by stubs which
57 generate a fatal error if a Perl script attempts to call one of these routines.
58 You can link Perl directly to your TCP/IP stack's library, *as long as* it
59 supplies shims for stdio routines which will properly handle both sockets and
60 normal file descriptors. This is necessary because Perl does not distinguish
61 between the two, and will try to make normal stdio calls such as read() and
62 getc() on socket file descriptors. If you'd like to link Perl directly to
63 your IP stack, then make the following changes:
64 - In Descrip.MMS, locate the section beginning with .ifdef SOCKET, and
65 change the SOCKLIB macro so that it translates to the filespec of your
66 IP stack's socket library. This will be added to the RTL options file.
67 - Edit the file SockAdapt.H in the [.VMS] subdirectory so that it
68 includes the Socket.h, In.H, Inet.H, NetDb.H, and, if necessary,
69 Errno.H header files for your IP stack, or so that it declares the
70 standard TCP/IP constants and data structures appropriately. (See
71 the distributed copy of SockAdapt.H for a collection of the structures
72 needed by Perl itself, and [.ext.Socket]Socket.xs for a list of the
73 constants used by the Socket extension, if you elect to built it.)
74 You should also define any logical names necessary for your C compiler
75 to find these files before invoking MM[KS] to build Perl.
76 - Edit the file SockAdapt.C in the [.VMS] subdirectory so that it
77 contains routines which substitute for any IP library routines
78 required by Perl which your IP stack does not provide. This may
79 require a little trial and error; we'll try to compile a complete
80 list soon of socket routines required by Perl.
83 * Building Perl under VMS
85 Since you're reading this, presumably you've unpacked the Perl distribution
86 into its directory tree, in which you will find a [.vms] subdirectory below
87 the directory in which this file is found. If this isn't the case, then you'll
88 need to unpack the distribution properly, or manually edit Descrip.MMS or
89 the VMS Makefile to alter directory paths as necessary. (I'd advise using the
90 `normal' directory tree, at least for the first time through.) This
91 subdirectory contains several files, among which are the following:
92 Config.VMS - A template C header file set up for VMS.
93 Descrip.MMS - The MMS/MMK dependency file for building Perl
94 GenConfig.Pl - A Perl script to generate Config.SH retrospectively
95 from Config.VMS, since the Configure shell script which
96 normally generates Config.SH doesn't run under VMS.
97 GenOpt.Com - A little DCL procedure used to write some linker options
98 files, since not all make utilities can do this easily.
99 Gen_ShrFls.Pl - A Perl script which generates linker options files and
100 MACRO declarations for PerlShr.Exe.
101 Makefile - The make dependency file for building Perl
102 MMS2Make.Pl - A Perl script used to generate Makefile from Descrip.MMS
103 VMSish.H - C header file containing VMS-specific definitions
104 VMS.C - C source code for VMS-specific routines
105 WriteMain.Pl - A Perl script used to generate perlmain.c during the build.
106 There may also be other files pertaining to features under development; for the
107 most part, you can ignore them.
109 Config.VMS and Decrip.MMS/Makefile are set up to build a version of Perl which
110 includes all features known to work when this release was assembled. If you
111 have code at your site which would support additional features (e.g. emulation
112 of Unix system calls), feel free to make the appropriate changes to these
113 files. (Note: Do not use or edit config.h in the main Perl source directory;
114 it is superseded by the current Config.VMS during the build.) You may also
115 wish to make site-specific changes to Descrip.MMS or Makefile to reflect local
116 conventions for naming of files, etc.
118 At the moment, system-specific information which becomes part of the Perl
119 Config extension is hard-coded into the file genconfig.pl in the vms
120 subdirectory. Before you build Perl, you should make any changes to the list
121 at the end of this file necessary to reflect your system (e.g your hostname and
124 Examine the information at the beginning of Descrip.MMS for information about
125 specifying alternate C compilers or building a version of Perl with debugging
126 support. For instance, if you want to use DECC, you'll need to include the
127 /macro="decc=1" qualifier to MMS (If you're using make, these options are not
128 supported.) If you're on an AXP system, define the macro __AXP__ (MMK does
129 this for you), and DECC will automatically be selected.
131 To start the build, set default to the main source directory. Since
132 Descrip.MMS assumes that VMS commands have their usual meaning, and makes use
133 of command-line macros, you may want to be certain that you haven't defined DCL
134 symbols which would interfere with the build. Then, if you are using MMS or
136 $ MMS/Descrip=[.VMS] ! or MMK
137 If you are using make, say
138 $ Make -f [.VMS]Makefile
139 Note that the Makefile doesn't support conditional compilation, is
140 set up to use VAXC on a VAX, and does not include socket support. You can
141 either edit the Makefile by hand, using Descrip.MMS as a guide, or use the
142 Makefile to build Miniperl.Exe, and then run the Perl script MMS2Make.pl,
143 found in the [.VMS] subdirectory, to generate a new Makefile with the options
144 appropriate to your site.
146 Note for sites using early versions of DECC: A bug in some versions of the
147 DECC RTL causes newlines to be lost when writing to a pipe. This causes
148 Gen_ShrFls.pl to fail, since it can't read the preprocessor output to identify
149 global variables and routines. You can work around this problem by defining
150 the macro DECC_PIPES_BROKEN when you invoke MMS or MMK.
152 This will build the following files:
153 Miniperl.Exe - a stand-alone version of without any extensions.
154 Miniperl has all the intrinsic capabilities of Perl,
155 but cannot make use of the DynaLoader or any
156 extensions which use XS code.
157 PerlShr.Exe - a shareable image containing most of Perl's internal
158 routines and global variables. Perl.Exe is linked to
159 this image, as are all dynamic extensions, so everyone's
160 using the same set of global variables and routines.
161 Perl.Exe - the main Perl executable image. It's contains the
162 main() routine, plus code for any statically linked
164 PerlShr_Attr.Opt - A linker options file which specifies psect attributes
165 matching those in PerlShr.Exe. It should be used when
166 linking images against PerlShr.Exe
167 PerlShr_Bld.Opt - A linker options file which specifies various things
168 used to build PerlShr.Exe. It should be used when
169 rebuilding PerlShr.Exe via MakeMaker-produced
170 Descrip.MMS files for static extensions.
171 [.Lib]Config.pm - the Perl extension which saves configuration information
172 about Perl and your system.
173 [.lib]DynaLoader.pm - The Perl extension which performs dynamic linking of
174 shareable images for extensions.
175 There are, of course, a number of other files created for use during the build.
176 Once you've got the binaries built, you may wish to `build' the `tidy' or
177 `clean' targets to remove extra files.
180 * Installing Perl once it's built
182 Once the build is complete, you'll need to do the following:
183 - Put PerlShr.Exe in a common directory, and make it world-readable.
184 If you place it in a location other than Sys$Share, you'll need to
185 define the logical name PerlShr to point to the image.
186 - Put Perl.Exe in a common directory, and make it world executable
187 - Define a foreign command to invoke Perl, using a statement like
188 $ Perl == "$dev:[dir]Perl.Exe"
189 - Create a world-readable directory tree for Perl library modules,
190 scripts, and what-have-you, and define PERL_ROOT as a rooted logical
191 name pointing to the top of this tree (i.e. if your Perl files were
192 going to live in DKA1:[Util.Perl5...], then you should
193 $ Define/Translation=Concealed Perl_Root DKA1:[Util.Perl5.]
194 (Be careful to follow the rules for rooted logical names; in particular,
195 remember that a rooted logical name cannot have as its device portion
196 another rooted logical name - you've got to supply the actual device name
197 and directory path to the root directory.)
198 - Define the logical name PERLSHR as the full file specification of
199 PERLSHR.EXE, so executable images linked to it can find it. Alternatively,
200 you can justput PERLSHR.EXE int SYS$SHARE.
201 - Place the files from the [.lib...] directory tree in the distribution
202 package into a [.lib...] directory tree off the root directory described
204 - Most of the Perl documentation lives in the [.pod] subdirectory, and
205 is written in a simple markup format which can be easily read. In this
206 directory as well are pod2man and pod2html translators to reformat the
207 docs for common display engines; a pod2hlp translator is under development.
208 Information on Perl can also be gleaned from the files in the [.doc]
209 subdirectory (internals documents and summaries of changes), and from
210 the test scripts in the [.t...] subdirectories.
214 * For more information
216 If you're interested in more information on Perl in general, consult the Usenet
217 newsgroup comp.lang.perl. The FAQ for that group provides pointers to other
218 online sources of information, as well as books describing Perl in depth.
220 If you're interested in up-to-date information on Perl development and
221 internals, you might want to subscribe to the perl5-porters mailing list. You
222 can do this by sending a message to perl5-porters-request@nicoh.com, containing
224 subscribe perl5-porters
225 This is a moderately high-volume list at the moment (25-50 messages/day).
227 If you're interested in ongoing information about the VMS port, you can
228 subscribe to the VMSperl mailing list by sending a request to
229 bailey@genetics.upenn.edu (it's to a human, not a list server - this is a small
230 operation at the moment). And, as always, we welcome any help or code you'd
231 like to offer - you can send mail to bailey@genetics.upenn.edu or directly to
232 the VMSperl list at vmsperl@genetics.upenn.edu.
234 Finally, if you'd like to try out the latest changes to VMS Perl, you can
235 retrieve a test distribution kit by anonymous ftp from genetics.upenn.edu, in
236 the file [.perl5]perl5_ppp_yymmddx.zip, where "ppp" is the current Perl
237 patchlevel, and "yymmddx" is a sequence number indicating the date that
238 particular kit was assembled. These test kits contain "unofficial" patches
239 from the perl5-porters group, test patches for important bugs, and VMS-specific
240 fixes and improvements which have occurred since the last Perl release. Most
241 of these changes will be incorporated in the next release of Perl, but until
242 Larry Wall's looked at them and said they're OK, none of them should be
245 Good luck using Perl. Please let us know how it works for you - we can't
246 guarantee that we'll be able to fix bugs quickly, but we'll try, and we'd
247 certainly like to know they're out there.
252 There are, of course, far too many people involved in the porting and testing
253 of Perl to mention everyone who deserves it, so please forgive us if we've
254 missed someone. That said, special thanks are due to the following:
255 Tim Adye <T.J.Adye@rl.ac.uk>
256 for the VMS emulations of getpw*()
257 David Denholm <denholm@conmat.phys.soton.ac.uk>
258 for extensive testing and provision of pipe and SocketShr code,
259 Mark Pizzolato <mark@infocomm.com>
260 for the getredirection() code
261 Rich Salz <rsalz@bbn.com>
262 for readdir() and related routines
263 Denis Haskin <DWH@epub.ziff.com>
264 for work on a pod-to-hlp translator for the Perl documentation
265 Richard Dyson <dyson@blaze.physics.uiowa.edu> and
266 Kent Covert <kacovert@miavx1.acs.muohio.edu>
267 for additional testing on the AXP.
268 and to the entire VMSperl group for useful advice and suggestions. In addition
269 the perl5-porters, especially Andy Dougherty <doughera@lafcol.lafayette.edu>
270 and Tim Bunce <Tim.Bunce@ig.co.uk>, deserve credit for their creativity and
271 willingness to work with the VMS newcomers. Finally, the greatest debt of
272 gratitude is due to Larry Wall <lwall@netlabs.com>, for having the ideas which
273 have made our sleepless nights possible.