Last Revised 02-June-1998 by Dan Sugalski Originally by Charles Bailey * Important safety tip The build and install procedures have changed significantly from the 5.004 releases! Make sure you read the "Building Perl" and "Installing Perl" sections before you build or install. * Intro The VMS port of Perl is as functionally complete as any other Perl port (and as complete as the ports on some Unix systems). The Perl binaries provide all the Perl system calls that are either available under VMS or reasonably emulated. There are some incompatibilites in process handling (e.g the fork/exec model for creating subprocesses doesn't do what you might expect under Unix), mainly because VMS and Unix handle processes and sub-processes very differently. There are still some unimplemented system functions, and of coursse we could use modules implementing useful VMS system services, so if you'd like to lend a hand we'd love to have you. Join the Perl Porting Team Now! The current sources and build procedures have been tested on a VAX using VaxC and Dec C, and on an AXP using Dec C. If you run into problems with other compilers, please let us know. There are issues with varions versions of Dec C, so if you're not running a relatively modern version, check the Dec C issues section later on in this document. * Other required software In addition to VMS, you'll need: 1) A C compiler. Dec C for AXP, or VAX C, Dec C, or gcc for the VAX. 2) A make tool. Dec's MMS (v2.6 or later), or MadGoat's free MMS analog MMK (available from ftp.madgoat.com/madgoat) both work just fine. Gnu Make might work, but it's been so long since anyone's tested it that we're not sure. MMK's free, though, so go ahead and use that. If you want to include socket support, you'll need a TCP stack and either Dec C, or socket libraries. See the Socket Support topic for more details. * Building Perl Building perl has two steps, configuration and compilation. To configure perl (a necessary first step), issue the command @CONFIGURE from the top of an unpacked perl directory. You'll be asked a series of questions, and the answers to them (along with the capabilities of your C compiler and network stack) will determine how perl's built. If you've got multiple C compilers installed, you'll have your choice of which one to use. Using Dec C is recommended over Vax C--the compiler is newer, and supported. (Vax C was decommisioned around 1993) Various older versions had some gotchas, so if you're using a version older than 5.2, check the Dec C Issues section. We'll also point out that Dec C will get you at least a ten-fold increase in line-oriented IO over Vax C. The optimizer is amazingly better, too. If you can use Dec C, then you *really*, *really* should. The configuration script will print out, at the very end, the MMS or MMK command you need to compile perl. Issue it (exactly as printed) to start the build. Once you issue your MMS command, sit back and wait. Perl should build and link without a problem. If it doesn't, check the Gotchas to watch out for section. If that doesn't help, send some mail to the VMSPERL mailing list. Instructions are in the Mailing Lists section. As a handy shortcut, the command: @CONFIGURE "-des" (note the quotes and case) will choose reasonable defaults. (It takes Dec C over Vax C, Dec C sockets over SOCKETSHR sockets, and either over no sockets) * Testing Perl Once Perl has built cleanly, you need to test it to make sure things work. This step is very important--there are always things that can go wrong somehow and get you a dysfunctional Perl. Testing is very easy, though, as there's a full test suite in the perl distribution. To run the tests, enter the *exact* MMS line you used to compile Perl and add the word "test" to the end, like this: Compile Command: $MMS/Macro=("__AXP__=1","decc=1","DECCRTL_SOCKETS=1") Test Command: $MMS/Macro=("__AXP__=1","decc=1","DECCRTL_SOCKETS=1") test MMS will run all the tests. This may take some time, as there are a lot of tests. If any tests fail, there will be a note made on-screen. At the end of all the tests, a summary of the tests, the number passed and failed, and the time taken will be displayed. If any tests fail, it means something's wrong with Perl. If the test suite hangs (some tests can take upwards of two or three minutes, or more if you're on an especially slow machine, depending on you machine speed, so don't be hasty), then the test *after* the last one displayed failed. Don't install Perl unless you're confident that you're OK. Regardless of how confident you are, make a bug report to the VMSPerl mailing list. If one or more tests fail, you can get more info on the failure by issuing this command sequence: $ @[.VMS]TEST .typ "-v" [.subdir]test.T where ".typ" is the file type of the Perl images you just built (if you didn't do anything special, use .EXE), and "[.subdir]test.T" is the test that failed. For example, with a normal Perl build, if the test indicated that [.op]time failed, then you'd do this: $ @[.VMS]TEST .EXE "-v" [.OP]TIME.T When you send in a bug report for failed tests, please include the output from this command, which is run from the main source directory: MCR []MINIPERL "-V" Note that "-V" really is a capital V in double quotes. This will dump out a couple of screens worth of config info, and can help us diagnose the problem. * Cleaning up and starting fresh If you need to recompile from scratch, you have to make sure you clean up first. There's a procedure to do it--enter the *exact* MMS line you used to compile and add "realclean" at the end, like this: Compile Command: $MMS/Macro=("__AXP__=1","decc=1","DECCRTL_SOCKETS=1") Cleanup Command: $MMS/Macro=("__AXP__=1","decc=1","DECCRTL_SOCKETS=1") realclean If you don't do this, things may behave erratically. They might not, too, so it's best to be sure and do it. * Installing Perl There are several steps you need to take to get Perl installed and running. 1) Create a directory somewhere and define the concealed logical PERL_ROOT to point to it. For example, DEFINE/TRANS=(CONC,TERM) PERL_ROOT dka200:[perl.] 2) Run the install script via: MMS install or MMK install If for some reason it complains about target INSTALL being up to date, throw a /FORCE switch on the MMS or MMK command. 3) Either define the symbol PERL somewhere, such as SYS$MANAGER:SYLOGIN.COM, to be "PERL :== $PERL_ROOT:[000000]PERL.EXE", or install Perl into DCLTABLES.EXE (Check out the section "Installing Perl into DCLTABLES" for more info), or put the image in a directory that's in your DCL$PATH (if you're using VMS 6.2 or higher). 4) Optionally define the command PERLDOC as PERLDOC :== $PERL_ROOT:[000000]PERL PERL_ROOT:[LIB.POD]PERLDOC.COM -T Note that if you wish to use most as a pager please see ftp://space.mit.edu/pub/davis/ for both most and slang. 5) Optionally define the command PERLBUG (the Perl bug report generator) as PERLBUG :== $PERL_ROOT:[000000]PERL PERL_ROOT:[LIB]PERLBUG.COM" 6) Optionally define the command POD2MAN (Converts POD files to nroff source suitable for converting to man pages. Also quiets complaints during module builds) as DEFINE/NOLOG POD2MAN PERL_ROOT:[LIB.POD]POD2MAN.COM POD2MAN :== $PERL_ROOT:[000000]PERL POD2MAN * Installing Perl into DCLTABLES Execute the following command file to define PERL as a DCL command. You'll need CMKRNL priv to install the new dcltables.exe. $ create perl.cld ! ! modify to reflect location of your perl.exe ! define verb perl image perl_root:[000000]perl.exe cliflags (foreign) $! $ set command perl /table=sys$common:[syslib]dcltables.exe - /output=sys$common:[syslib]dcltables.exe $ install replace sys$common:[syslib]dcltables.exe $ exit * Changing compile-time things Most of the user-definable features of Perl are enabled or disabled in [.VMS]CONFIG.VMS. There's code in there to Do The Right Thing, but that may end up being the wrong thing for you. Make sure you understand what you're doing, since changes here can get you a busted perl. Odds are that there's nothing here to change, unless you're on a version of VMS later than 6.2 and Dec C later than 5.6. Even if you are, the correct values will still be chosen, most likely. Poking around here should be unnecessary. The one exception is the various *DIR install locations. Changing those requires changes in genconfig.pl as well. Be really careful if you need to change these,a s they can cause some fairly subtle problems. * Extra things in the Perl distribution In addition to the standard stuff that gets installed, there are two optional extensions, DCLSYM and STDIO, that are handy. Instructions for these two modules are in [.VMS.EXT.DCLSYM] and [.VMS.EXT.STDIO], respectively. * Socket Support Perl includes a number of functions for IP sockets, which are available if you choose to compile Perl with socket support. (See the section Compiling Perl for more info on selecting a socket stack) Since IP networking is an optional addition to VMS, there are several different IP stacks available. How well integrated they are into the system depends on the stack, your version of VMS, and the version of your C compiler. The most portable solution uses the SOCKETSHR library. In combination with either UCX or NetLib, this supports all the major TCP stacks (Multinet, Pathways, TCPWare, UCX, and CMU) on all versions of VMS Perl runs on, with all the compilers on both VAX and Alpha. The socket interface is also consistent across versions of VMS and C compilers. It has a problem with UDP sockets when used with Multinet, though, so you should be aware of that. The other solution available is to use the socket routines built into Dec C. Which routines are available depend on the version of VMS you're running, and require proper UCX emulation by your TCP/IP vendor. Relatively current versions of Multinet, TCPWare, Pathway, and UCX all provide the required libraries--check your manuals or release notes to see if your version is new enough. * Reporting Bugs If you come across what you think might be a bug in Perl, please report it. There's a script in PERL_ROOT:[UTILS], perlbug, that walks you through the process of creating a bug report. This script includes details of your installation, and is very handy. Completed bug reports should go to PERLBUG@PERL.COM. * Gotchas to watch out for Probably the single biggest gotcha in compiling Perl is giving the wrong switches to MMS/MMK when you build. Use *exactly* what the configure script prints! The next big gotcha is directory depth. Perl can create directories four and five levels deep during the build, so you don't have to be too deep to start to hit the RMS 8 level point. It's best to do a $DEFINE/TRANS=(CONC,TERM) PERLSRC disk:[dir.dir.dir.perldir.]" (note the trailing period) and $SET DEFAULT PERLSRC:[000000] before building. Perl modules can be just as bad (or worse), so watch out for them, too. The configuration script will warn if it thinks you're too deep. Finally, the third thing that bites people is leftover pieces from a failed build. If things go wrong, make sure you do a "(MMK|MMS|make) realclean" before you rebuild. * Dec C issues Note to DECC users: Some early versions (pre-5.2, some pre-4. If you're Dec C 5.x or higher, with current patches if anym you're fine) of the DECCRTL contained a few bugs which affect Perl performance: - Newlines are lost on I/O through pipes, causing lines to run together. This shows up as RMS RTB errors when reading from a pipe. You can work around this by having one process write data to a file, and then having the other read the file, instead of the pipe. This is fixed in version 4 of DECC. - The modf() routine returns a non-integral value for some values above INT_MAX; the Perl "int" operator will return a non-integral value in these cases. This is fixed in version 4 of DECC. - On the AXP, if SYSNAM privilege is enabled, the CRTL chdir() routine changes the process default device and directory permanently, even though the call specified that the change should not persist after Perl exited. This is fixed by DEC CSC patch AXPACRT04_061. * Mailing Lists There are several mailing lists available to the Perl porter. For VMS specific issues (including both Perl questions and installation problems) there is the VMSPERL mailing list. It's usually a low-volume (10-12 messages a week) mailing list. The subscription address is VMSPERL-REQUEST@NEWMAN.UPENN.EDU. Send a mail message with just the words SUBSCRIBE VMSPERL in the body of the message. The VMSPERL mailing list address is VMSPERL@NEWMAN.UPENN.EDU. Any mail sent there gets echoed to all subscribers of the list. The Perl5-Porters list is for anyone involved in porting Perl to a platform. This includes you, if you want to participate. It's a high-volume list (60-100 messages a day during active development times), so be sure you want to be there. The subscription address is Perl5-Porters-request@perl.org. Send a message with just the word SUBSCRIBE in the body. The posting address is Perl5-Porters@perl.org. * Acknowledgements A real big thanks needs to go to Charles Bailey , who is ultimately responsible for Perl 5.004 running on VMS. Without him, nothing the rest of us have done would be at all important. There are, of course, far too many people involved in the porting and testing of Perl to mention everyone who deserves it, so please forgive us if we've missed someone. That said, special thanks are due to the following: Tim Adye for the VMS emulations of getpw*() David Denholm for extensive testing and provision of pipe and SocketShr code, Mark Pizzolato for the getredirection() code Rich Salz for readdir() and related routines Peter Prymmer for extensive contributions to recent version support, development of VMS-specific extensions, and dissemination of information about VMS Perl, the Stanford Synchrotron Radiation Laboratory and the Laboratory of Nuclear Studies at Cornell University for the the opportunity to test and develop for the AXP, and to the entire VMSperl group for useful advice and suggestions. In addition the perl5-porters deserve credit for their creativity and willingness to work with the VMS newcomers. Finally, the greatest debt of gratitude is due to Larry Wall , for having the ideas which have made our sleepless nights possible. Thanks, The VMSperl group