VMS the C<%ENV> table is much more than a per-process key-value string
table.
+On VMS, some entries in the %ENV hash are dynamically created when
+their key is used on a read if they did not previously exist. The
+values for C<$ENV{HOME}>, C<$ENV{TERM}>, C<$ENV{HOME}>, and C<$ENV{USER}>,
+are known to be dynamically generated. The specific names that are
+dynamically generated may vary with the version of the C library on VMS,
+and more may exist than is documented.
+
+On VMS by default, changes to the %ENV hash are persistent after the process
+exits. This can cause unintended issues.
+
Don't count on signals or C<%SIG> for anything.
Don't count on filename globbing. Use C<opendir>, C<readdir>, and
some large number. C<$offset> can then be added to a Unix time value
to get what should be the proper value on any system.
-On Windows (at least), you shouldn't pass a negative value to C<gmtime> or
-C<localtime>.
-
=head2 Character sets and character encoding
Assume very little about character sets.
later. If the bytes are native 8-bit bytes, you can use the C<bytes>
pragma. If the bytes are in a string (regular expression being a
curious string), you can often also use the C<\xHH> notation instead
-of embedding the bytes as-is. If they are in some particular legacy
-encoding (ether single-byte or something more complicated), you can
-use the C<encoding> pragma. (If you want to write your code in UTF-8,
-you can use either the C<utf8> pragma, or the C<encoding> pragma.)
-The C<bytes> and C<utf8> pragmata are available since Perl 5.6.0, and
-the C<encoding> pragma since Perl 5.8.0.
+of embedding the bytes as-is. (If you want to write your code in UTF-8,
+you can use the C<utf8>.) The C<bytes> and C<utf8> pragmata are
+available since Perl 5.6.0.
=head2 System Resources
dgux dgux AViiON-dgux
DYNIX/ptx dynixptx i386-dynixptx
FreeBSD freebsd freebsd-i386
+ Haiku haiku BePC-haiku
Linux linux arm-linux
Linux linux i386-linux
Linux linux i586-linux
HP-UX hpux PA-RISC1.1
IRIX irix irix
Mac OS X darwin darwin
- MachTen PPC machten powerpc-machten
NeXT 3 next next-fat
NeXT 4 next OPENSTEP-Mach
openbsd openbsd i386-openbsd
=item *
The EMX environment for DOS, OS/2, etc. emx@iaehv.nl,
-http://www.leo.org/pub/comp/os/os2/leo/gnu/emx+gcc/index.html or
ftp://hobbes.nmsu.edu/pub/os2/dev/emx/ Also L<perlos2>.
=item *
=item *
-The MacPerl Pages, http://www.macperl.com/ .
-
-=item *
-
The MacPerl mailing lists, http://lists.perl.org/ .
=item *
again with the optionally the exact case.
RMS had an eight level limit on directory depths from any rooted logical
-(allowing 16 levels overall) prior to VMS 7.2. Hence
-C<PERL_ROOT:[LIB.2.3.4.5.6.7.8]> is a valid directory specification but
-C<PERL_ROOT:[LIB.2.3.4.5.6.7.8.9]> is not. F<Makefile.PL> authors might
-have to take this into account, but at least they can refer to the former
-as C</PERL_ROOT/lib/2/3/4/5/6/7/8/>.
+(allowing 16 levels overall) prior to VMS 7.2, and even with versions of
+VMS on VAX up through 7.3. Hence C<PERL_ROOT:[LIB.2.3.4.5.6.7.8]> is a
+valid directory specification but C<PERL_ROOT:[LIB.2.3.4.5.6.7.8.9]> is
+not. F<Makefile.PL> authors might have to take this into account, but at
+least they can refer to the former as C</PERL_ROOT/lib/2/3/4/5/6/7/8/>.
+
+Pumpkings and module integrators can easily see whether files with too many
+directory levels have snuck into the core by running the following in the
+top-level source directory:
+
+ $ perl -ne "$_=~s/\s+.*//; print if scalar(split /\//) > 8;" < MANIFEST
+
The VMS::Filespec module, which gets installed as part of the build
process on VMS, is a pure Perl module that can easily be installed on
=item *
-vmsperl list, majordomo@perl.org
-
-(Put the words C<subscribe vmsperl> in message body.)
+vmsperl list, vmsperl-subscribe@perl.org
=item *
(installed as L<perlvos>). Perl on VOS can accept either VOS- or
Unix-style file specifications as in either of the following:
- C<< $ perl -ne "print if /perl_setup/i" >system>notices >>
- C<< $ perl -ne "print if /perl_setup/i" /system/notices >>
+ $ perl -ne "print if /perl_setup/i" >system>notices
+ $ perl -ne "print if /perl_setup/i" /system/notices
or even a mixture of both as in:
- C<< $ perl -ne "print if /perl_setup/i" >system/notices >>
+ $ perl -ne "print if /perl_setup/i" >system/notices
Even though VOS allows the slash character to appear in object
names, because the VOS port of Perl interprets it as a pathname
delimiting character, VOS files, directories, or links whose names
contain a slash character cannot be processed. Such files must be
renamed before they can be processed by Perl. Note that VOS limits
-file names to 32 or fewer characters.
+file names to 32 or fewer characters, file names cannot start with a
+C<-> character, or contain any character matching C<< tr/ !%&'()*+;<>?// >>
The value of C<$^O> on VOS is "VOS". To determine the architecture that
you are running on without resorting to loading all of C<%Config> you
=head2 Other perls
Perl has been ported to many platforms that do not fit into any of
-the categories listed above. Some, such as AmigaOS, Atari MiNT,
-BeOS, HP MPE/iX, QNX, Plan 9, and VOS, have been well-integrated
-into the standard Perl source code kit. You may need to see the
-F<ports/> directory on CPAN for information, and possibly binaries,
-for the likes of: aos, Atari ST, lynxos, riscos, Novell Netware,
-Tandem Guardian, I<etc.> (Yes, we know that some of these OSes may
-fall under the Unix category, but we are not a standards body.)
+the categories listed above. Some, such as AmigaOS, BeOS, HP MPE/iX,
+QNX, Plan 9, and VOS, have been well-integrated into the standard
+Perl source code kit. You may need to see the F<ports/> directory
+on CPAN for information, and possibly binaries, for the likes of:
+aos, Atari ST, lynxos, riscos, Novell Netware, Tandem Guardian,
+I<etc.> (Yes, we know that some of these OSes may fall under the
+Unix category, but we are not a standards body.)
Some approximate operating system names and their C<$^O> values
in the "OTHER" category include:
=item *
-Atari, F<README.mint> and Guido Flohr's web page
-http://stud.uni-sb.de/~gufl0000/
-
-=item *
-
Be OS, F<README.beos>
=item *
HP 300 MPE/iX, F<README.mpeix> and Mark Bixby's web page
-http://www.bixby.org/mark/perlix.html
+http://www.bixby.org/mark/porting.html
=item *
and applications are executable, and there are no uid/gid
considerations. C<-o> is not supported. (S<Mac OS>)
+C<-w> only inspects the read-only file attribute (FILE_ATTRIBUTE_READONLY),
+which determines whether the directory can be deleted, not whether it can
+be written to. Directories always have read and write access unless denied
+by discretionary access control lists (DACLs). (S<Win32>)
+
C<-r>, C<-w>, C<-x>, and C<-o> tell whether the file is accessible,
which may not reflect UIC-based file protections. (VMS)
C<-b>, C<-c>, C<-k>, C<-g>, C<-p>, C<-u>, C<-A> are not implemented.
(S<Mac OS>)
-C<-g>, C<-k>, C<-l>, C<-p>, C<-u>, C<-A> are not particularly meaningful.
+C<-g>, C<-k>, C<-l>, C<-u>, C<-A> are not particularly meaningful.
(Win32, VMS, S<RISC OS>)
+C<-p> is not particularly meaningful. (VMS, S<RISC OS>)
+
C<-d> is true if passed a device spec without an explicit directory.
(VMS)
=item gmtime
-Same portability caveats as L<localtime>.
+In theory, gmtime() is reliable from -2**63 to 2**63-1. However,
+because work arounds in the implementation use floating point numbers,
+it will become inaccurate as the time gets larger. This is a bug and
+will be fixed in the future.
=item ioctl FILEHANDLE,FUNCTION,SCALAR
$sig is 0 and the specified process exists, it returns true without
actually terminating it. (Win32)
+C<kill(-9, $pid)> will terminate the process specified by $pid and
+recursively all child processes owned by it. This is different from
+the Unix semantics, where the signal will be delivered to all
+processes in the same process group as the process specified by
+$pid. (Win32)
+
Is not supported for process identification number of 0 or negative
numbers. (VMS)
Link count not updated because hard links are not quite that hard
(They are sort of half-way between hard and soft links). (AmigaOS)
-Hard links are implemented on Win32 (Windows NT and Windows 2000)
-under NTFS only.
+Hard links are implemented on Win32 under NTFS only. They are
+natively supported on Windows 2000 and later. On Windows NT they
+are implemented using the Windows POSIX subsystem support and the
+Perl process will need Administrator or Backup Operator privileges
+to create hard links.
Available on 64 bit OpenVMS 8.2 and later. (VMS)
=item localtime
-Because Perl currently relies on the native standard C localtime()
-function, it is only safe to use times between 0 and (2**31)-1. Times
-outside this range may result in unexpected behavior depending on your
-operating system's implementation of localtime().
+localtime() has the same range as L<gmtime>, but because time zone
+rules change its accuracy for historical and future times may degrade
+but usually by no more than an hour.
=item lstat
Opening a process does not automatically flush output handles on some
platforms. (SunOS, Solaris, HP-UX)
-=item pipe
-
-Very limited functionality. (MiNT)
-
=item readlink
Not implemented. (Win32, VMS, S<RISC OS>)
=item socketpair
-Not implemented. (Win32, S<RISC OS>, VOS, VM/ESA)
+Not implemented. (S<RISC OS>, VOS, VM/ESA)
Available on 64 bit OpenVMS 8.2 and later. (VMS)
some versions of cygwin when doing a stat("foo") and if not finding it
may then attempt to stat("foo.exe") (Cygwin)
+On Win32 stat() needs to open the file to determine the link count
+and update attributes that may have been changed through hard links.
+Setting ${^WIN32_SLOPPY_STAT} to a true value speeds up stat() by
+not performing this operation. (Win32)
+
=item symlink
-Not implemented. (Win32, VMS, S<RISC OS>)
+Not implemented. (Win32, S<RISC OS>)
+
+Implemented on 64 bit VMS 8.3. VMS requires the symbolic link to be in Unix
+syntax if it is intended to resolve to a valid path.
=item syscall
I<scalar> will call the native command line direct and no such emulation
of a child Unix program will exists. Mileage B<will> vary. (S<RISC OS>)
-Far from being POSIX compliant. Because there may be no underlying
-/bin/sh tries to work around the problem by forking and execing the
-first token in its argument string. Handles basic redirection
-("<" or ">") on its own behalf. (MiNT)
-
Does not automatically flush output handles on some platforms.
(SunOS, Solaris, HP-UX)
As of July 2002 (the Perl release 5.8.0), the following platforms are
able to build Perl from the standard source code distribution
-available at http://www.cpan.org/src/index.html
+available at http://www.cpan.org/src/
AIX
BeOS
Greenhills
ISC
MachTen 68k
- MiNT
MPC
NEWS-OS
NextSTEP
L<perlaix>, L<perlamiga>, L<perlapollo>, L<perlbeos>, L<perlbs2000>,
L<perlce>, L<perlcygwin>, L<perldgux>, L<perldos>, L<perlepoc>,
L<perlebcdic>, L<perlfreebsd>, L<perlhurd>, L<perlhpux>, L<perlirix>,
-L<perlmachten>, L<perlmacos>, L<perlmacosx>, L<perlmint>, L<perlmpeix>,
+L<perlmacos>, L<perlmacosx>, L<perlmpeix>,
L<perlnetware>, L<perlos2>, L<perlos390>, L<perlos400>,
L<perlplan9>, L<perlqnx>, L<perlsolaris>, L<perltru64>,
L<perlunicode>, L<perlvmesa>, L<perlvms>, L<perlvos>,
projects / p5sagit/p5-mst-13.2.git / blobdiff