interconversion between VMS and Unix syntax; its
documentation provides more details.
-Filenames are, of course, still case-insensitive. For
-consistency, most Perl routines return filespecs using
-lower case letters only, regardless of the case used in
-the arguments passed to them. (This is true only when
-running under VMS; Perl respects the case-sensitivity
-of OSs like Unix.)
+Perl is now in the process of evolving to follow the setting of
+the DECC$* feature logicals in the interpretation of UNIX pathnames.
+This is still a work in progress.
+
+For handling extended characters, and case sensitivity, as long as
+DECC$POSIX_COMPLIANT_PATHNAMES, DECC$FILENAME_UNIX_REPORT, and
+DECC$FILENAME_UNIX_ONLY are not set, then the older Perl behavior
+for conversions of file specifications from UNIX to VMS is followed,
+except that VMS paths with concealed rooted logicals are now
+translated correctly to UNIX paths.
+
+With those features set, then new routines may handle the translation,
+because some of the rules are different. The presence of ./.../
+in a UNIX path is no longer translated to the VMS [...]. It will
+translate to [.^.^.^.]. To be compatible with what MakeMaker expects,
+if a VMS path can not be translated to a UNIX path when unixify
+is called, it is passed through unchanged. So unixify("[...]") will
+return "[...]".
+
+The handling of extended characters will also be better with the
+newer translation routines. But more work is needed to fully support
+extended file syntax names. In particular, at this writing Pathtools
+can not deal with directories containing some extended characters.
+
+There are several ambiguous cases where a conversion routine can not
+determine if an input filename is in UNIX format or in VMS format,
+since now both VMS UNIX file specifications can have characters in
+them that could be mistaken for syntax delimiters of the other type.
+So some pathnames simply can not be used in a mode that allows either
+type of pathname to be present.
+
+Perl will tend to assume that an ambiguous filename is in UNIX format.
+
+Allowing "." as a version delimiter is simply incompatible with
+determining if a pathname is already VMS format or UNIX with the
+extended file syntax. There is no way to know if "perl-5.8.6" that
+TAR produces is a UNIX "perl-5.8.6" or a VMS "perl-5.8;6" when
+passing it to unixify() or vmsify().
+
+The DECC$FILENAME_UNIX_REPORT or the DECC$FILENAME_UNIX_ONLY logical
+names control how Perl interprets filenames.
+
+The DECC$FILENAME_UNIX_ONLY setting has not been tested at this time.
+Perl uses traditional OpenVMS file specifications internally and in
+the test harness, so this mode may have limited use, or require more
+changes to make usable.
+
+Everything about DECC$FILENAME_UNIX_REPORT should be assumed to apply
+to DECC$FILENAME_UNIX_ONLY mode. The DECC$FILENAME_UNIX_ONLY differs
+in that it expects all filenames passed to the C runtime to be already
+in UNIX format.
+
+Again, currently most of the core Perl modules have not yet been updated
+to understand that VMS is not as limited as it use to be. Fixing that
+is a work in progress.
+
+The logical name DECC$POSIX_COMPLIANT_PATHNAMES is new with the
+RMS Symbolic Link SDK. This version of Perl does not support it being set.
+
+
+Filenames are case-insensitive on VAX, and on ODS-2 formatted
+volumes on ALPHA and I64.
+
+On ODS-5 volumes filenames are case preserved and on newer
+versions of OpenVMS can be optionally case sensitive.
+
+On ALPHA and I64, Perl is in the process of being changed to follow the
+process case sensitivity setting to report if the file system is case
+sensitive.
+
+Perl programs should not assume that VMS is case blind, or that
+filenames will be in lowercase.
+
+Programs should use the File::Spec:case_tolerant setting to determine
+the state, and not the $^O setting.
+
+For consistency, when the above feature is clear and when not
+otherwise overridden by DECC feature logicals, most Perl routines
+return file specifications using lower case letters only,
+regardless of the case used in the arguments passed to them.
+(This is true only when running under VMS; Perl respects the
+case-sensitivity of OSs like Unix.)
We've tried to minimize the dependence of Perl library
modules on Unix syntax, but you may find that some of these,
of this in the Perl distribution itself, please let us know,
so we can try to work around them.
+Also when working on Perl programs on VMS, if you need a syntax
+in a specific operating system format, then you need to either
+check the appropriate DECC$ feature logical, or call a conversion
+routine to force it to that format.
+
=head2 Wildcard expansion
File specifications containing wildcards are allowed both on
Similarly, the resultant filespec will contain the file version
only if one was present in the input filespec.
+
=head2 Pipes
Input and output pipes to Perl filehandles are supported; the
them in double-quotes on the command line, since the CRTL
downcases all unquoted strings.
+On newer 64 bit versions of OpenVMS, a process setting now
+controls if the quoting is needed to preserve the case of
+command line arguments.
+
=over 4
=item -i
getsockopt, listen, recv, select(system call)*,
send, setsockopt, shutdown, socket
+The following function is available on Perls built on 64 bit OpenVMS 8.2
+with hard links enabled on an ODS-5 formatted build disk. If someone with
+an OpenVMS 7.3-1 system were to modify configure.com and test the results,
+this feature can be brought back to OpenVMS 7.3-1 and later. Hardlinks
+must be enabled on the build disk because if the build procedure sees
+this feature enabled, it uses it.
+
+ link
+
+The following functions are available on Perls built on 64 bit OpenVMS
+8.2 and can be implemented on OpenVMS 7.3-2 if someone were to modify
+configure.com and test the results. (While in the build, at the time
+of this writing, they have not been specifically tested.)
+
+ getgrgid, getgrnam, getpwnam, getpwuid,
+ setgrent, ttyname
+
+The following functions are available on Perls built on 64 bit OpenVMS 8.2
+and later. (While in the build, at the time of this writing, they have
+not been specifically tested.)
+
+ statvfs, socketpair
+
+The following functions are expected to soon be available on Perls built
+on 64 bit OpenVMS 8.2 or later with the RMS Symbolic link package. Use
+of symbolic links at this time effectively requires the
+DECC$POSIX_COMPLIANT_PATHNAMES to defined as 3, and operating in a
+DECC$FILENAME_UNIX_REPORT mode.
+
+ lchown, link, lstat, readlink, symlink
=over 4
=item File tests
specification without an explicit directory (e.g. C<DUA1:>), as
well as if passed a directory.
+There are DECC feature logicals AND ODS-5 volume attributes that
+also control what values are returned for the date fields.
+
Note: Some sites have reported problems when using the file-access
tests (C<-r>, C<-w>, and C<-x>) on files accessed via DEC's DFS.
Specifically, since DFS does not currently provide access to the
corresponding VMS message string, as retrieved by sys$getmsg().
Setting C<$^E> sets vaxc$errno to the value specified.
+While Perl attempts to keep the vaxc$errno value to be current, if
+errno is not EVMSERR, it may not be from the current operation.
+
=item $?
The "status value" returned in C<$?> is synthesized from the
portably test for successful completion of subprocesses. The
low order 8 bits of C<$?> are always 0 under VMS, since the
termination status of a process may or may not have been
-generated by an exception. The next 8 bits are derived from
-the severity portion of the subprocess' exit status: if the
-severity was success or informational, these bits are all 0;
-if the severity was warning, they contain a value of 1; if the
-severity was error or fatal error, they contain the actual
-severity bits, which turns out to be a value of 2 for error
-and 4 for fatal error.
+generated by an exception.
+
+The next 8 bits contain the termination status of the program.
+
+If the child process follows the convention of C programs
+compiled with the _POSIX_EXIT macro set, the status value will
+contain the actual value of 0 to 255 returned by that program
+on a normal exit.
+
+With the _POSIX_EXIT macro set, the exit code of zero is represented
+as 1, and the values from 1 to 255 are encoded by the equation
+VMS_status = 0x35a000 + (exit_code * 8).
+
+For other termination statuses, the severity portion of the
+subprocess' exit status: if the severity was success or
+informational, these bits are all 0; if the severity was
+warning, they contain a value of 1; if the severity was
+error or fatal error, they contain the actual severity bits,
+which turns out to be a value of 2 for error and 4 for fatal error.
As a result, C<$?> will always be zero if the subprocess' exit
status indicated successful completion, and non-zero if a
-warning or error occurred. Conversely, when setting C<$?> in
-an END block, an attempt is made to convert the POSIX value
-into a native status intelligible to the operating system upon
-exiting Perl. What this boils down to is that setting C<$?>
-to zero results in the generic success value SS$_NORMAL, and
-setting C<$?> to a non-zero value results in the generic
-failure status SS$_ABORT. See also L<perlport/exit>.
+warning or error occurred or a program compliant with encoding
+_POSIX_EXIT values was run and set a status.
+
+How can you tell the difference? You can not unless you look at
+the ${^CHILD_ERROR_NATIVE} code. The ${^CHILD_ERROR_NATIVE} code
+returns the actual VMS status value and check the severity bits.
+If the severity bits are clear, then the numeric value is code
+passed back from the application.
+
+In practice, Perl scripts that call programs that return _POSIX_EXIT
+type status codes will be expecting those codes, and programs that
+call traditional VMS programs will be expecting the previous behavior.
+
+And success is always the code 0.
+
+Conversely, when setting C<$?> in an END block, an attempt is made
+to convert the POSIX value into a native status intelligible to
+the operating system upon exiting Perl. What this boils down to
+is that setting C<$?> to zero results in the generic success value
+SS$_NORMAL, and setting C<$?> to a non-zero value results in the
+generic failure status SS$_ABORT. See also L<perlport/exit>.
The pragma C<use vmsish 'status'> makes C<$?> reflect the actual
VMS exit status instead of the default emulation of POSIX status
=head1 Revision date
-This document was last updated on 01-May-2002, for Perl 5,
+This document was last updated on 14-Oct-2005, for Perl 5,
patchlevel 8.
=head1 AUTHOR
Charles Bailey bailey@cor.newman.upenn.edu
Craig Berry craigberry@mac.com
Dan Sugalski dan@sidhe.org
+John Malmberg wb8tyw@qsl.net
projects / p5sagit/p5-mst-13.2.git / commitdiff