Directions for building and installing Perl 5 can be found in
the file F<README.vms> in the main source directory of the
-Perl distribution..
+Perl distribution.
=head1 Organization of Perl Images
=head2 Core Images
-During the installation process, three Perl images are produced.
+During the build process, three Perl images are produced.
F<Miniperl.Exe> is an executable image which contains all of
the basic functionality of Perl, but cannot take advantage of
-Perl extensions. It is used to generate several files needed
-to build the complete Perl and various extensions. Once you've
-finished installing Perl, you can delete this image.
-
-Most of the complete Perl resides in the shareable image
-F<PerlShr.Exe>, which provides a core to which the Perl executable
-image and all Perl extensions are linked. You should place this
-image in F<Sys$Share>, or define the logical name F<PerlShr> to
-translate to the full file specification of this image. It should
-be world readable. (Remember that if a user has execute only access
-to F<PerlShr>, VMS will treat it as if it were a privileged shareable
-image, and will therefore require all downstream shareable images to be
-INSTALLed, etc.)
-
+Perl XS extensions and has a hard-wired list of library locations
+for loading pure-Perl modules. It is used extensively to build and
+test Perl and various extensions, but is not installed.
+
+Most of the complete Perl resides in the shareable image F<PerlShr.Exe>,
+which provides a core to which the Perl executable image and all Perl
+extensions are linked. It is generally located via the logical name
+F<PERLSHR>. While it's possible to put the image in F<SYS$SHARE> to
+make it loadable, that's not recommended. And while you may wish to
+INSTALL the image for performance reasons, you should not install it
+with privileges; if you do, the result will not be what you expect as
+image privileges are disabled during Perl start-up.
Finally, F<Perl.Exe> is an executable image containing the main
entry point for Perl, as well as some initialization code. It
$ 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 if you are running a version of VMS prior
-to V7.1 you shouldn't nest the source directory
-too deeply in your directory structure lest you exceed 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.site_perl.auto>I<Arch>.I<Extname>F<]> 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<.>). (See the MakeMaker documentation
-for more details on installation options for extensions.)
-However, it can be manually placed in any of several locations:
+is sufficient to handle most extensions. (See the MakeMaker
+documentation for more details on installation options for
+extensions.)
=over 4
expects, if a VMS path cannot be translated to a Unix path, it is
passed through unchanged, so C<unixify("[...]")> will return C<[...]>.
-The handling of extended characters is largely complete in the
-VMS-specific C infrastructure of Perl, but more work is still needed to
-fully support extended syntax filenames in several core modules. In
-particular, at this writing PathTools has only partial support for
-directories containing some extended characters.
-
There are several ambiguous cases where a conversion routine cannot
determine whether an input filename is in Unix format or in VMS format,
since now both VMS and Unix file specifications may have characters in
=head2 Filename Case
-Perl follows VMS defaults and override settings in preserving (or not
-preserving) filename case. Case is not preserved on ODS-2 formatted
-volumes on any architecture. On ODS-5 volumes, filenames may be case
-preserved depending on process and feature settings. Perl now honors
-DECC$EFS_CASE_PRESERVE and DECC$ARGV_PARSE_STYLE on those systems where
-the CRTL supports these features. When these features are not enabled
-or the CRTL does not support them, Perl follows the traditional CRTL
-behavior of downcasing command-line arguments and returning file
-specifications in lower case only.
+Perl enables DECC$EFS_CASE_PRESERVE and DECC$ARGV_PARSE_STYLE by
+default. Note that the latter only takes effect when extended parse
+is set in the process in which Perl is running. When these features
+are explicitly disabled in the environment or the CRTL does not support
+them, Perl follows the traditional CRTL behavior of downcasing command-line
+arguments and returning file specifications in lower case only.
I<N. B.> It is very easy to get tripped up using a mixture of other
programs, external utilities, and Perl scripts that are in varying
such as MMK or MMS may generate a filename in all upper case even on an
ODS-5 volume. If this filename is later retrieved by a Perl script or
module in a case preserving environment, that upper case name may not
-match the mixed-case or lower-case exceptions of the Perl code. Your
+match the mixed-case or lower-case expectations of the Perl code. Your
best bet is to follow an all-or-nothing approach to case preservation:
either don't use it at all, or make sure your entire toolchain and
application environment support and use it.
=head1 PERL5LIB and PERLLIB
-The PERL5LIB and PERLLIB logical names work as documented in L<perl>,
-except that the element separator is '|' instead of ':'. The
+The PERL5LIB and PERLLIB environment elements work as documented in L<perl>,
+except that the element separator is, by default, '|' instead of ':'.
+However, when running under a Unix shell as determined by the logical
+name C<GNV$UNIX_SHELL>, the separator will be ':' as on Unix systems. The
directory specifications may use either VMS or Unix syntax.
=head1 The Perl Forked Debugger
This allows the programmer to look at the execution stack and variables to
find out the cause of the exception. As the debugger is being invoked as
the Perl interpreter is about to do a fatal exit, continuing the execution
-in debug mode is usally not practical.
+in debug mode is usually not practical.
Starting Perl in the VMS debugger may change the program execution
profile in a way that such problems are not reproduced.
caller, chdir, chmod, chown, chomp, chop, chr,
close, closedir, cos, crypt*, defined, delete, die, do, dump*,
each, endgrent, endpwent, eof, eval, exec*, exists, exit, exp,
- fileno, flock getc, getgrent*, getgrgid*, getgrnam, getlogin, getppid,
- getpwent*, getpwnam*, getpwuid*, glob, gmtime*, goto,
+ fileno, flock getc, getgrent*, getgrgid*, getgrnam, getlogin,
+ getppid, getpwent*, getpwnam*, getpwuid*, glob, gmtime*, goto,
grep, hex, ioctl, import, index, int, join, keys, kill*,
- last, lc, lcfirst, lchown*, length, link*, local, localtime, log, lstat, m//,
- map, mkdir, my, next, no, oct, open, opendir, ord, pack,
- pipe, pop, pos, print, printf, push, q//, qq//, qw//,
- qx//*, quotemeta, rand, read, readdir, readlink*, redo, ref, rename,
- require, reset, return, reverse, rewinddir, rindex,
+ last, lc, lcfirst, lchown*, length, link*, local, localtime, log,
+ lstat, m//, map, mkdir, my, next, no, oct, open, opendir, ord,
+ pack, pipe, pop, pos, print, printf, push, q//, qq//, qw//,
+ qx//*, quotemeta, rand, read, readdir, readlink*, redo, ref,
+ rename, require, reset, return, reverse, rewinddir, rindex,
rmdir, s///, scalar, seek, seekdir, select(internal),
select (system call)*, setgrent, setpwent, shift, sin, sleep,
socketpair, sort, splice, split, sprintf, sqrt, srand, stat,
See L</"$?"> for a description of the encoding of the Unix value to
produce a native VMS status containing it.
-
=item dump
Rather than causing Perl to abort and dump core, the C<dump>
=item CRTL_ENV
-This string tells Perl to consult the CRTL's internal C<environ>
-array of key-value pairs, using I<name> as the key. In most cases,
-this contains only a few keys, but if Perl was invoked via the C
-C<exec[lv]e()> function, as is the case for CGI processing by some
-HTTP servers, then the C<environ> array may have been populated by
-the calling program.
+This string tells Perl to consult the CRTL's internal C<environ> array
+of key-value pairs, using I<name> as the key. In most cases, this
+contains only a few keys, but if Perl was invoked via the C
+C<exec[lv]e()> function, as is the case for some embedded Perl
+applications or when running under a shell such as GNV bash, the
+C<environ> array may have been populated by the calling program.
=item CLISYM_[LOCAL]
you make while Perl is running do not affect the behavior of C<%ENV>.
If F<PERL_ENV_TABLES> is not defined, then Perl defaults to consulting
first the logical name tables specified by F<LNM$FILE_DEV>, and then
-the CRTL C<environ> array.
+the CRTL C<environ> array. This default order is reversed when the
+logical name F<GNV$UNIX_SHELL> is defined, such as when running under
+GNV bash.
-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.
+For operations on %ENV entries based on logical names or DCL symbols, the
+key string is treated as if it were entirely uppercase, regardless of the
+case actually specified in the Perl expression. Entries in %ENV based on the
+CRTL's environ array preserve the case of the key string when stored, and
+lookups are case sensitive.
When an element of C<%ENV> is read, the locations to which
F<PERL_ENV_TABLES> points are checked in order, and the value
(The same is done if an existing logical name was defined in
executive or kernel mode; an existing user or supervisor mode
logical name is reset to the new value.) If the value is an empty
-string, the logical name's translation is defined as a single NUL
-(ASCII 00) character, since a logical name cannot translate to a
+string, the logical name's translation is defined as a single C<NUL>
+(ASCII C<\0>) character, since a logical name cannot translate to a
zero-length string. (This restriction does not apply to CLI symbols
or CRTL C<environ> values; they are set to the empty string.)
-An element of the CRTL C<environ> array can be set only if your
-copy of Perl knows about the CRTL's C<setenv()> function. (This is
-present only in some versions of the DECCRTL; check C<$Config{d_setenv}>
-to see whether your copy of Perl was built with a CRTL that has this
-function.)
-
-When an element of C<%ENV> is set to C<undef>,
-the element is looked up as if it were being read, and if it is
-found, it is deleted. (An item "deleted" from the CRTL C<environ>
-array is set to the empty string; this can only be done if your
-copy of Perl knows about the CRTL C<setenv()> function.) Using
-C<delete> to remove an element from C<%ENV> has a similar effect,
-but after the element is deleted, another attempt is made to
-look up the element, so an inner-mode logical name or a name in
-another location will replace the logical name just deleted.
-In either case, only the first value found searching PERL_ENV_TABLES
-is altered. It is not possible at present to define a search list
+
+When an element of C<%ENV> is set to C<undef>, the element is looked
+up as if it were being read, and if it is found, it is deleted. (An
+item "deleted" from the CRTL C<environ> array is set to the empty
+string.) Using C<delete> to remove an element from C<%ENV> has a
+similar effect, but after the element is deleted, another attempt is
+made to look up the element, so an inner-mode logical name or a name
+in another location will replace the logical name just deleted. In
+either case, only the first value found searching PERL_ENV_TABLES is
+altered. It is not possible at present to define a search list
logical name via %ENV.
The element C<$ENV{DEFAULT}> is special: when read, it returns
process-permanent files, such as C<SYS$INPUT> and C<SYS$OUTPUT>.
The translations for these logical names are prepended with a
two-byte binary value (0x1B 0x00) that needs to be stripped off
-if you wantto use it. (In previous versions of Perl it wasn't
+if you want to use it. (In previous versions of Perl it wasn't
possible to get the values of these logical names, as the null
byte acted as an end-of-string marker)
https://perl5.git.perl.org / perl5.git / blobdiff