-=head1 Notes on Perl 5 for VMS
+=head1 NAME
+
+perlvms - VMS-specific documentation for Perl
+
+=head1 DESCRIPTION
Gathered below are notes describing details of Perl 5's
behavior on VMS. They are a supplement to the regular Perl 5
missed something you think should appear here, please don't
hesitate to drop a line to vmsperl@genetics.upenn.edu.
-=head1 Organization of Perl
+=head1 Organization of Perl Images
-=head2 Perl Images
+=head2 Core Images
During the installation process, three Perl images are produced.
F<Miniperl.Exe> is an executable image which contains all of
the C<MakeMaker> library modules supplied with Perl to generate
a F<Descrip.MMS> file for the extension.
-=head3 Installing static extensions
+=head2 Installing static extensions
Since static extensions are incorporated directly into
F<PerlShr.Exe>, you'll have to rebuild Perl to incorporate a
the library module for extension Foo::Bar would be copied
to a F<[.Foo.Bar]> subdirectory).
-=head3 Installic dynamic extensions
-
-First, you'll need to compile the XS code into a shareable image,
-either by hand or using the F<Descrip.MMS> supplied with the
-extension. If you're building the shareable image by hand, please
-note the following points:
- - The shareable image must be linked to F<PerlShr.Exe>, so it
- has access to Perl's global variables and routines. In
- order to specify the correct attributes for psects in
- F<PerlShr.Exe>, you should include the linker options file
- F<PerlShr_Attr.Opt> in the Link command. (This file is
- generated when F<PerlShr.Exe> is built, and is found in the
- main Perl source directory.
- - The entry point for the C<boot_>I<Extname> routine (where
- I<Extname> is the name of the extension, with all C<::>
- replaced by C<__>) must be a universal symbol. No other
- universal symbols are required to use the shareable image
- with Perl, though you may want to include additional
- universal symbols if you plan to share code or data among
- different extensions.
-The shareable image can be placed in any of several locations:
- - the F<[.Auto.>I<Extname>F<]> subdirectory of one of
- the directories in C<@INC>, where I<Extname> is the
- name of the extension, with each C<::> translated to C<.>
- (e.g. for extension Foo::Bar, you would use the
- F<[.Auto.Foo.Bar]> subdirectory), or
+=head2 Installing dynamic extensions
+
+In general, the distributed kit for a Perl extension includes
+a file named Makefile.PL, which is a Perl program which is used
+to create a F<Descrip.MMS> file which can be used to build and
+install the files required by the extension. The kit should be
+unpacked into a directory tree B<not> under the main Perl source
+directory, and the procedure for building the extension is simply
+
+ $ perl Makefile.PL ! Create Descrip.MMS
+ $ mmk ! Build necessary files
+ $ mmk test ! Run test code, if supplied
+ $ mmk install ! Install into public Perl tree
+
+I<N.B.> The procedure by which extensions are built and
+tested creates several levels (at least 4) under the
+directory in which the extension's source files live.
+For this reason, you shouldn't nest the source directory
+too deeply in your directory structure, lest you eccedd RMS'
+maximum of 8 levels of subdirectory in a filespec. (You
+can use rooted logical names to get another 8 levels of
+nesting, if you can't place the files near the top of
+the physical directory structure.)
+
+VMS support for this process in the current release of Perl
+is sufficient to handle most extensions. However, it does
+not yet recognize extra libraries required to build shareable
+images which are part of an extension, so these must be added
+to the linker options file for the extension by hand. For
+instance, if the F<PGPLOT> extension to Perl requires the
+F<PGPLOTSHR.EXE> shareable image in order to properly link
+the Perl extension, then the line C<PGPLOTSHR/Share> must
+be added to the linker options file F<PGPLOT.Opt> produced
+during the build process for the Perl extension.
+
+By default, the shareable image for an extension is placed
+in the F<[.Lib.Auto.I<Arch>.I<Extname>]> directory of the
+installed Perl directory tree (where I<Arch> is F<VMS_VAX> or
+F<VMS_AXP>, and I<Extname> is the name of the extension, with
+each C<::> translated to C<.>). However, it can be manually
+placed in any of several locations:
+ - the F<[.Lib.Auto.I<Extname>]> subdirectory of one of
+ the directories in C<@INC>, or
- one of the directories in C<@INC>, or
- a directory which the extensions Perl library module
passes to the DynaLoader when asking it to map
is the portion of the extension's name after the last C<::>, which
translates to the full file specification of the shareable image.
-Once you've got the shareable image set up, you should copy the
-extension's Perl library module to the appropriate library directory
-(see the section above on installing static extensions).
-
=head1 Installation
Directions for building and installing Perl 5 can be found in
separator is '|' instead of ':'. The directory
specifications may use either VMS or Unix syntax.
-=head1 %ENV
-
-Reading the elements of the %ENV array returns the
-translation of the logical name specified by the key,
-according to the normal search order of access modes and
-logical name tables. In addition, the keys C<home>,
-C<path>,C<term>, and C<user> return the CRTL "environment
-variables" of the same names. The key C<default> returns the
-current default device and directory specification.
-
-Setting an element of %ENV defines a supervisor-mode logical
-name in the process logical name table. C<Undef>ing or
-C<delete>ing an element of %ENV deletes the equivalent user-
-mode or supervisor-mode logical name from the process logical
-name table. If you use C<undef>, the %ENV element remains
-empty. If you use C<delete>, another attempt is made at
-logical name translation after the deletion, so an inner-mode
-logical name or a name in another logical name table will
-replace the logical name just deleted.
-
-In all operations on %ENV, the key string is treated as if it
-were entirely uppercase, regardless of the case actually
-specified in the Perl expression.
-
=head1 Perl functions
As of the time this document was last revised, the following
file tests*, abs, alarm, atan, binmode*, bless,
caller, chdir, chmod, chown, chomp, chop, chr,
- close, closedir, cos, defined, delete, die, do,
- each, endpwent, eof, eval, exec*, exists, exit,
- exp, fileno, fork*, getc, getpwent*, getpwnam*,
- getpwuid*, glob, goto, grep, hex, import, index,
- int, join, keys, kill, last, lc, lcfirst, length,
- local, localtime, log, m//, map, mkdir, my, next,
- no, oct, open, opendir, ord, pack, pipe, pop, pos,
- print, printf, push, q//, qq//, qw//, qx//,
- quotemeta, rand, read, readdir, redo, ref, rename,
+ close, closedir, cos, crypt*, defined, delete,
+ die, do, each, endpwent, eof, eval, exec*, exists,
+ exit, exp, fileno, fork*, getc, getlogin, getpwent*,
+ getpwnam*, getpwuid*, glob, gmtime*, goto, grep, hex,
+ import, index, int, join, keys, kill*, last, lc,
+ lcfirst, length, local, localtime, log, m//, map,
+ mkdir, my, next, no, oct, open, opendir, ord, pack,
+ pipe, pop, pos, print, printf, push, q//, qq//, qw//,
+ qx//, quotemeta, rand, read, readdir, redo, ref, rename,
require, reset, return, reverse, rewinddir, rindex,
- rmdir, s///, scalar, seek, seekdir, select(internal)*,
- setpwent, shift, sin, sleep, sort, splice, split,
- sprintf, sqrt, srand, stat, study, substr, sysread,
- system*, syswrite, tell, telldir, tie, time, times*,
- tr///, uc, ucfirst, umask, undef, unlink, unpack,
- untie, unshift, use, utime*, values, vec, wait,
- waitpid*, wantarray, warn, write, y///
+ rmdir, s///, scalar, seek, seekdir, select(internal),
+ select (system call)*, setpwent, shift, sin, sleep,
+ sort, splice, split, sprintf, sqrt, srand, stat,
+ study, substr, sysread, system*, syswrite, tell,
+ telldir, tie, time, times*, tr///, uc, ucfirst, umask,
+ undef, unlink*, unpack, untie, unshift, use, utime*,
+ values, vec, wait, waitpid*, wantarray, warn, write, y///
The following functions were not implemented in the VMS port,
and calling them produces a fatal error (usually) or
undefined behavior (rarely, we hope):
- chroot, crypt, dbmclose, dbmopen, dump, fcntl,
- flock, getlogin, getpgrp, getppid, getpriority,
- getgrent, kill, getgrgid, getgrnam, setgrent,
- endgrent, gmtime, ioctl, link, lstst, msgctl,
- msgget, msgsend, msgrcv, readlink,
- select(system call), semctl, semget, semop,
- setpgrp, setpriority, shmctl, shmget, shmread,
- shmwrite, socketpair, symlink, syscall, truncate
+ chroot, dbmclose, dbmopen, dump, fcntl, flock,
+ getpgrp, getppid, getpriority, getgrent, getgrgid,
+ getgrnam, setgrent, endgrent, ioctl, link, lstat,
+ msgctl, msgget, msgsend, msgrcv, readlink, semctl,
+ semget, semop, setpgrp, setpriority, shmctl, shmget,
+ shmread, shmwrite, socketpair, symlink, syscall, truncate
The following functions may or may not be implemented,
depending on what type of socket support you've built into
getnetent, getprotoent, getservent, sethostent,
setnetent, setprotoent, setservent, endhostent,
endnetent, endprotoent, endservent, getsockname,
- getsockopt, listen, recv, send, setsockopt,
- shutdown, socket
+ getsockopt, listen, recv, select(system call)*,
+ send, setsockopt, shutdown, socket
=item File tests
return TRUE whenever called, but will not affect I/O
operations on the filehandle given as its argument.
+=item crypt PLAINTEXT, USER
+
+The C<crypt> operator uses the C<sys$hash_password> system
+service to generate the hashed representation of PLAINTEXT.
+If USER is a valid username, the algorithm and salt values
+are taken from that user's UAF record. If it is not, then
+the preferred algorithm and a salt of 0 are used. The
+quadword encrypted value is returned as an 8-character string.
+
+The value returned by C<crypt> may be compared against
+the encrypted password from the UAF returned by the C<getpw*>
+functions, in order to authenticate users. If you're
+going to do this, remember that the encrypted password in
+the UAF was generated using uppercase username and
+password strings; you'll have to upcase the arguments to
+C<crypt> to insure that you'll get the proper value:
+
+ sub validate_passwd {
+ my($user,$passwd) = @_;
+ my($pwdhash);
+ if ( !($pwdhash = (getpwnam($user))[1]) ||
+ $pwdhash ne crypt("\U$passwd","\U$name") ) {
+ intruder_alert($name);
+ }
+ return 1;
+ }
+
=item exec LIST
The C<exec> operator behaves in one of two different ways.
use the C<system> operator or piped filehandles instead.
=item getpwent
+
=item getpwnam
+
=item getpwuid
These operators obtain the information described in L<perlfunc>,
contains the owner field from the UAF record. The C<$quota>
item is not used.
+=item gmtime
+
+The C<gmtime> operator will function properly if you have a
+working CRTL C<gmtime()> routine, or if the logical name
+SYS$TIMEZONE_DIFFERENTIAL is defined as the number of seconds
+which must be added to UTC to yield local time. (This logical
+name is defined automatically if you are running a version of
+VMS with built-in UTC support.) If neither of these cases is
+true, a warning message is printed, and C<undef> is returned.
+
+=item kill
+
+In most cases, C<kill> kill is implemented via the CRTL's C<kill()>
+function, so it will behave according to that function's
+documentation. If you send a SIGKILL, however, the $DELPRC system
+service is is called directly. This insures that the target
+process is actually deleted, if at all possible. (The CRTL's C<kill()>
+function is presently implemented via $FORCEX, which is ignored by
+supervisor-mode images like DCL.)
+
+Also, negative signal values don't do anything special under
+VMS; they're just converted to the corresponding positive value.
+
+=item select (system call)
+
+If Perl was not built with socket support, the system call
+version of C<select> is not available at all. If socket
+support is present, then the system call version of
+C<select> functions only for file descriptors attached
+to sockets. It will not provide information about regular
+files or pipes, since the CRTL C<select()> routine does not
+provide this functionality.
+
=item stat EXPR
Since VMS keeps track of files according to a different scheme
The C<system> operator creates a subprocess, and passes its
arguments to the subprocess for execution as a DCL command.
-Since the subprocess is created directly via lib$spawn, any
+Since the subprocess is created directly via C<lib$spawn()>, any
valid DCL command string may be specified. If LIST consists
of the empty string, C<system> spawns an interactive DCL subprocess,
in the same fashion as typiing B<SPAWN> at the DCL prompt.
accumulate the times of suprocesses spawned via pipes, L<system>,
or backticks.
+=item unlink LIST
+
+C<unlink> will delete the highest version of a file only; in
+order to delete all versions, you need to say
+ 1 while (unlink LIST);
+You may need to make this change to scripts written for a
+Unix system which expect that after a call to C<unlink>,
+no files with the names passed to C<unlink> will exist.
+(Note: This can be changed at compile time; if you
+C<use Config> and C<$Config{'d_unlink_all_versions'}> is
+C<define>, then C<unlink> will delete all versions of a
+file on the first call.)
+
+C<unlink> will delete a file if at all possible, even if it
+requires changing file protection (though it won't try to
+change the protection of the parent directory). You can tell
+whether you've got explicit delete access to a file by using the
+C<VMS::Filespec::candelete> operator. For instance, in order
+to delete only files to which you have delete access, you could
+say something like
+ sub safe_unlink {
+ my($file,$num);
+ foreach $file (@_) {
+ next unless VMS::Filespec::candelete($file);
+ $num += unlink $file;
+ }
+ $num;
+ }
+Finally, if C<unlink> has to change the file protection to
+delete the file, and you interrupt it in midstream, the file
+may be left intact, but with a changed ACL allowing you delete
+access.
+
=item utime LIST
Since ODS-2, the VMS file structure for disk files, does not keep
The FLAGS argument is ignored in all cases.
+=head1 Perl variables
+
+=item %ENV
+
+Reading the elements of the %ENV array returns the
+translation of the logical name specified by the key,
+according to the normal search order of access modes and
+logical name tables. If you append a semicolon to the
+logical name, followed by an integer, that integer is
+used as the translation index for the logical name,
+so that you can look up successive values for search
+list logical names. For instance, if you say
+
+ $ Define STORY once,upon,a,time,there,was
+ $ perl -e "for ($i = 0; $i <= 6; $i++) " -
+ _$ -e "{ print $ENV{'foo'.$i},' '}"
+
+Perl will print C<ONCE UPON A TIME THERE WAS>.
+
+The %ENV keys C<home>, C<path>,C<term>, and C<user>
+return the CRTL "environment variables" of the same
+names, if these logical names are not defined. The
+key C<default> returns the current default device
+and directory specification, regardless of whether
+there is a logical name DEFAULT defined..
+
+Setting an element of %ENV defines a supervisor-mode logical
+name in the process logical name table. C<Undef>ing or
+C<delete>ing an element of %ENV deletes the equivalent user-
+mode or supervisor-mode logical name from the process logical
+name table. If you use C<undef>, the %ENV element remains
+empty. If you use C<delete>, another attempt is made at
+logical name translation after the deletion, so an inner-mode
+logical name or a name in another logical name table will
+replace the logical name just deleted. It is not possible
+at present to define a search list logical name via %ENV.
+
+In all operations on %ENV, the key string is treated as if it
+were entirely uppercase, regardless of the case actually
+specified in the Perl expression.
+
+=item $?
+
+Since VMS status values are 32 bits wide, the value of C<$?>
+is simply the final status value of the last subprocess to
+complete. This differs from the behavior of C<$?> under Unix,
+and under VMS' POSIX environment, in that the low-order 8 bits
+of C<$?> do not specify whether the process terminated normally
+or due to a signal, and you do not need to shift C<$?> 8 bits
+to the right in order to find the process' exit status.
+
+=item $!
+
+The string value of C<$!> is that returned by the CRTL's
+strerror() function, so it will include the VMS message for
+VMS-specific errors. The numeric value of C<$!> is the
+value of C<errno>, except if errno is EVMSERR, in which
+case C<$!> contains the value of vaxc$errno. Setting C<$!>
+always sets errno to the value specified, and sets vaxc$errno
+to 4 (NONAME-F-NOMSG).
+
=head1 Revision date
This document was last updated on 16-Dec-1994, for Perl 5,
-patchlevel 0.
+patchlevel 2.
+
+=head1 AUTHOR
+
+Charles Bailey bailey@genetics.upenn.edu
+
projects / p5sagit/p5-mst-13.2.git / blobdiff