your users lots of platform choices. On the other hand, when you have to
take advantage of some unique feature of a particular platform, as is
often the case with systems programming (whether for Unix, Windows,
-S<Mac OS>, VMS, etc.), consider writing platform-specific code.
+VMS, etc.), consider writing platform-specific code.
When the code will run on only two or three operating systems, you
may need to consider only the differences of those particular systems.
deliberate in your decision.
The material below is separated into three main sections: main issues of
-portability (L<"ISSUES">, platform-specific issues (L<"PLATFORMS">, and
+portability (L<"ISSUES">), platform-specific issues (L<"PLATFORMS">), and
built-in perl functions that behave differently on various ports
-(L<"FUNCTION IMPLEMENTATIONS">.
+(L<"FUNCTION IMPLEMENTATIONS">).
This information should not be considered complete; it includes possibly
transient information about idiosyncrasies of some of the ports, almost
Perl uses C<\n> to represent the "logical" newline, where what is
logical may depend on the platform in use. In MacPerl, C<\n> always
-means C<\015>. In DOSish perls, C<\n> usually means C<\012>, but
-when accessing a file in "text" mode, STDIO translates it to (or
-from) C<\015\012>, depending on whether you're reading or writing.
-Unix does the same thing on ttys in canonical mode. C<\015\012>
-is commonly referred to as CRLF.
-
-A common cause of unportable programs is the misuse of chop() to trim
-newlines:
-
- # XXX UNPORTABLE!
- while(<FILE>) {
- chop;
- @array = split(/:/);
- #...
- }
+means C<\015>. In DOSish perls, C<\n> usually means C<\012>, but when
+accessing a file in "text" mode, perl uses the C<:crlf> layer that
+translates it to (or from) C<\015\012>, depending on whether you're
+reading or writing. Unix does the same thing on ttys in canonical
+mode. C<\015\012> is commonly referred to as CRLF.
-You can get away with this on Unix and Mac OS (they have a single
-character end-of-line), but the same program will break under DOSish
-perls because you're only chop()ing half the end-of-line. Instead,
-chomp() should be used to trim newlines. The Dunce::Files module can
-help audit your code for misuses of chop().
+To trim trailing newlines from text lines use chomp(). With default
+settings that function looks for a trailing C<\n> character and thus
+trims in a portable way.
When dealing with binary files (or text files in binary mode) be sure
to explicitly set $/ to the appropriate value for your file format
such as z/OS (OS/390) or OS/400 (using the ILE, the PASE is ASCII-based)
the above material is similar to "Unix" but the code numbers change:
- LF eq \025 eq \x15 eq chr(21) eq CP-1047 21
- LF eq \045 eq \x25 eq \cU eq chr(37) eq CP-0037 37
+ LF eq \025 eq \x15 eq \cU eq chr(21) eq CP-1047 21
+ LF eq \045 eq \x25 eq chr(37) eq CP-0037 37
CR eq \015 eq \x0D eq \cM eq chr(13) eq CP-1047 13
CR eq \015 eq \x0D eq \cM eq chr(13) eq CP-0037 13
connections use the C<pack> and C<unpack> formats C<n> and C<N>, the
"network" orders. These are guaranteed to be portable.
+As of perl 5.9.2, you can also use the C<E<gt>> and C<E<lt>> modifiers
+to force big- or little-endian byte-order. This is useful if you want
+to store signed integers or 64-bit integers, for example.
+
You can explore the endianness of your platform by unpacking a
data structure packed in native format such as:
several root directories and various "unrooted" device files such NIL:
and LPT:).
-S<Mac OS> uses C<:> as a path separator instead of C</>.
+S<Mac OS> 9 and earlier used C<:> as a path separator instead of C</>.
The filesystem may support neither hard links (C<link>) nor
symbolic links (C<symlink>, C<readlink>, C<lstat>).
(e.g. the FAT filesystem limits the time granularity to two seconds).
The "inode change timestamp" (the C<-C> filetest) may really be the
-"creation timestamp" (which it is not in UNIX).
+"creation timestamp" (which it is not in Unix).
VOS perl can emulate Unix filenames with C</> as path separator. The
native pathname characters greater-than, less-than, number-sign, and
separator, or go native and use C<.> for path separator and C<:> to
signal filesystems and disk names.
-Don't assume UNIX filesystem access semantics: that read, write,
+Don't assume Unix filesystem access semantics: that read, write,
and execute are all the permissions there are, and even if they exist,
that their semantics (for example what do r, w, and x mean on
-a directory) are the UNIX ones. The various UNIX/POSIX compatibility
+a directory) are the Unix ones. The various Unix/POSIX compatibility
layers usually try to make interfaces like chmod() work, but sometimes
there simply is no good mapping.
use File::Spec::Functions;
chdir(updir()); # go up one directory
- $file = catfile(curdir(), 'temp', 'file.txt');
+ my $file = catfile(curdir(), 'temp', 'file.txt');
# on Unix and Win32, './temp/file.txt'
- # on Mac OS, ':temp:file.txt'
+ # on Mac OS Classic, ':temp:file.txt'
# on VMS, '[.temp]file.txt'
File::Spec is available in the standard distribution as of version
and even on systems where it might be tolerated, some utilities
might become confused by such whitespace.
-Many systems (DOS, VMS) cannot have more than one C<.> in their filenames.
+Many systems (DOS, VMS ODS-2) cannot have more than one C<.> in their
+filenames.
Don't assume C<< > >> won't be the first character of a filename.
Always use C<< < >> explicitly to open a file for reading, or even
better, use the three-arg version of open, unless you want the user to
be able to specify a pipe open.
- open(FILE, '<', $existing_file) or die $!;
+ open my $fh, '<', $existing_file) or die $!;
If filenames might use strange characters, it is safest to open it
with C<sysopen> instead of C<open>. C<open> is magic and can
VMS the C<%ENV> table is much more than a per-process key-value string
table.
+On VMS, some entries in the %ENV hash are dynamically created when
+their key is used on a read if they did not previously exist. The
+values for C<$ENV{HOME}>, C<$ENV{TERM}>, C<$ENV{HOME}>, and C<$ENV{USER}>,
+are known to be dynamically generated. The specific names that are
+dynamically generated may vary with the version of the C library on VMS,
+and more may exist than is documented.
+
+On VMS by default, changes to the %ENV hash are persistent after the process
+exits. This can cause unintended issues.
+
Don't count on signals or C<%SIG> for anything.
Don't count on filename globbing. Use C<opendir>, C<readdir>, and
directories.
Don't count on specific values of C<$!>, neither numeric nor
-especially the strings values-- users may switch their locales causing
+especially the strings values. Users may switch their locales causing
error messages to be translated into their languages. If you can
trust a POSIXish environment, you can portably use the symbols defined
by the Errno module, like ENOENT. And don't trust on the values of C<$!>
To convert $^X to a file pathname, taking account of the requirements
of the various operating system possibilities, say:
- use Config;
- $thisperl = $^X;
- if ($^O ne 'VMS')
- {$thisperl .= $Config{_exe} unless $thisperl =~ m/$Config{_exe}$/i;}
+
+ use Config;
+ my $thisperl = $^X;
+ if ($^O ne 'VMS')
+ {$thisperl .= $Config{_exe} unless $thisperl =~ m/$Config{_exe}$/i;}
To convert $Config{perlpath} to a file pathname, say:
- use Config;
- $thisperl = $Config{perlpath};
- if ($^O ne 'VMS')
- {$thisperl .= $Config{_exe} unless $thisperl =~ m/$Config{_exe}$/i;}
+
+ use Config;
+ my $thisperl = $Config{perlpath};
+ if ($^O ne 'VMS')
+ {$thisperl .= $Config{_exe} unless $thisperl =~ m/$Config{_exe}$/i;}
+
+=head2 Networking
+
+Don't assume that you can reach the public Internet.
+
+Don't assume that there is only one way to get through firewalls
+to the public Internet.
+
+Don't assume that you can reach outside world through any other port
+than 80, or some web proxy. ftp is blocked by many firewalls.
+
+Don't assume that you can send email by connecting to the local SMTP port.
+
+Don't assume that you can reach yourself or any node by the name
+'localhost'. The same goes for '127.0.0.1'. You will have to try both.
+
+Don't assume that the host has only one network card, or that it
+can't bind to many virtual IP addresses.
+
+Don't assume a particular network device name.
+
+Don't assume a particular set of ioctl()s will work.
+
+Don't assume that you can ping hosts and get replies.
+
+Don't assume that any particular port (service) will respond.
+
+Don't assume that Sys::Hostname (or any other API or command) returns
+either a fully qualified hostname or a non-qualified hostname: it all
+depends on how the system had been configured. Also remember that for
+things such as DHCP and NAT, the hostname you get back might not be
+very useful.
+
+All the above "don't":s may look daunting, and they are, but the key
+is to degrade gracefully if one cannot reach the particular network
+service one wants. Croaking or hanging do not look very professional.
=head2 Interprocess Communication (IPC)
store a date in an unambiguous representation. The ISO 8601 standard
defines YYYY-MM-DD as the date format, or YYYY-MM-DDTHH-MM-SS
(that's a literal "T" separating the date from the time).
-Please do use the ISO 8601 instead of making us to guess what
+Please do use the ISO 8601 instead of making us guess what
date 02/03/04 might be. ISO 8601 even sorts nicely as-is.
A text representation (like "1987-12-18") can be easily converted
into an OS-specific value using a module like Date::Parse.
it may be appropriate to calculate an offset for the epoch.
require Time::Local;
- $offset = Time::Local::timegm(0, 0, 0, 1, 0, 70);
-
-The value for C<$offset> in Unix will be C<0>, but in Mac OS will be
-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.
+ my $offset = Time::Local::timegm(0, 0, 0, 1, 0, 70);
-On Windows (at least), you shouldn't pass a negative value to C<gmtime> or
-C<localtime>.
+The value for C<$offset> in Unix will be C<0>, but in Mac OS Classic
+will be 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.
=head2 Character sets and character encoding
Do not assume anything about the ordering of the characters.
The lowercase letters may come before or after the uppercase letters;
-the lowercase and uppercase may be interlaced so that both `a' and `A'
-come before `b'; the accented and other international characters may
-be interlaced so that E<auml> comes before `b'.
+the lowercase and uppercase may be interlaced so that both "a" and "A"
+come before "b"; the accented and other international characters may
+be interlaced so that E<auml> comes before "b".
=head2 Internationalisation
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
for (0..10000000) {} # bad
for (my $x = 0; $x <= 10000000; ++$x) {} # good
- @lines = <VERY_LARGE_FILE>; # bad
+ my @lines = <$very_large_file>; # bad
- while (<FILE>) {$file .= $_} # sometimes bad
- $file = join('', <FILE>); # better
+ while (<$fh>) {$file .= $_} # sometimes bad
+ my $file = join('', <$fh>); # better
The last two constructs may appear unintuitive to most people. The
first repeatedly grows a string, whereas the second allocates a
=head2 Security
Most multi-user platforms provide basic levels of security, usually
-implemented at the filesystem level. Some, however, do
-not-- unfortunately. Thus the notion of user id, or "home" directory,
+implemented at the filesystem level. Some, however, unfortunately do
+not. Thus the notion of user id, or "home" directory,
or even the state of being logged-in, may be unrecognizable on many
platforms. If you write programs that are security-conscious, it
is usually best to know what type of system you will be running
under so that you can write code explicitly for that platform (or
class of platforms).
-Don't assume the UNIX filesystem access semantics: the operating
+Don't assume the Unix filesystem access semantics: the operating
system or the filesystem may be using some ACL systems, which are
richer languages than the usual rwx. Even if the rwx exist,
their semantics might be different.
(From security viewpoint testing for permissions before attempting to
do something is silly anyway: if one tries this, there is potential
-for race conditions-- someone or something might change the
+for race conditions. Someone or something might change the
permissions between the permissions check and the actual operation.
Just try the operation.)
-Don't assume the UNIX user and group semantics: especially, don't
+Don't assume the Unix user and group semantics: especially, don't
expect the C<< $< >> and C<< $> >> (or the C<$(> and C<$)>) to work
for switching identities (or memberships).
platforms; two, to provide users with information about whether
a given module works on a given platform.
+Also see:
+
=over 4
-=item Mailing list: cpan-testers@perl.org
+=item *
+
+Mailing list: cpan-testers-discuss@perl.org
+
+=item *
-=item Testing results: http://testers.cpan.org/
+Testing results: L<http://www.cpantesters.org/>
=back
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
be aware that each of these file specifications may have subtle
differences:
- $filespec0 = "c:/foo/bar/file.txt";
- $filespec1 = "c:\\foo\\bar\\file.txt";
- $filespec2 = 'c:\foo\bar\file.txt';
- $filespec3 = 'c:\\foo\\bar\\file.txt';
+ my $filespec0 = "c:/foo/bar/file.txt";
+ my $filespec1 = "c:\\foo\\bar\\file.txt";
+ my $filespec2 = 'c:\foo\bar\file.txt';
+ my $filespec3 = 'c:\\foo\\bar\\file.txt';
System calls accept either C</> or C<\> as the path separator.
However, many command-line utilities of DOS vintage treat C</> as
Windows NT MSWin32 MSWin32-x86 2 4 xx
Windows NT MSWin32 MSWin32-ALPHA 2 4 xx
Windows NT MSWin32 MSWin32-ppc 2 4 xx
- Windows 2000 MSWin32 MSWin32-x86 2 5 xx
- Windows XP MSWin32 MSWin32-x86 2 ?
+ Windows 2000 MSWin32 MSWin32-x86 2 5 00
+ Windows XP MSWin32 MSWin32-x86 2 5 01
+ Windows 2003 MSWin32 MSWin32-x86 2 5 02
+ Windows Vista MSWin32 MSWin32-x86 2 6 00
+ Windows 7 MSWin32 MSWin32-x86 2 6 01
+ Windows 7 MSWin32 MSWin32-x64 2 6 01
Windows CE MSWin32 ? 3
- Cygwin cygwin ?
+ Cygwin cygwin cygwin
The various MSWin32 Perl's can distinguish the OS they are running on
via the value of the fifth element of the list returned from
=item *
-The djgpp environment for DOS, http://www.delorie.com/djgpp/
+The djgpp environment for DOS, L<http://www.delorie.com/djgpp/>
and L<perldos>.
=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>.
+L<ftp://hobbes.nmsu.edu/pub/os2/dev/emx/> Also L<perlos2>.
=item *
=item *
-The ActiveState Pages, http://www.activestate.com/
+The ActiveState Pages, L<http://www.activestate.com/>
=item *
The Cygwin environment for Win32; F<README.cygwin> (installed
-as L<perlcygwin>), http://www.cygwin.com/
+as L<perlcygwin>), L<http://www.cygwin.com/>
=item *
The U/WIN environment for Win32,
-http://www.research.att.com/sw/tools/uwin/
+L<http://www.research.att.com/sw/tools/uwin/>
=item *
=back
-=head2 S<Mac OS>
-
-Any module requiring XS compilation is right out for most people, because
-MacPerl is built using non-free (and non-cheap!) compilers. Some XS
-modules that can work with MacPerl are built and distributed in binary
-form on CPAN.
-
-Directories are specified as:
-
- volume:folder:file for absolute pathnames
- volume:folder: for absolute pathnames
- :folder:file for relative pathnames
- :folder: for relative pathnames
- :file for relative pathnames
- file for relative pathnames
-
-Files are stored in the directory in alphabetical order. Filenames are
-limited to 31 characters, and may include any character except for
-null and C<:>, which is reserved as the path separator.
-
-Instead of C<flock>, see C<FSpSetFLock> and C<FSpRstFLock> in the
-Mac::Files module, or C<chmod(0444, ...)> and C<chmod(0666, ...)>.
-
-In the MacPerl application, you can't run a program from the command line;
-programs that expect C<@ARGV> to be populated can be edited with something
-like the following, which brings up a dialog box asking for the command
-line arguments.
-
- if (!@ARGV) {
- @ARGV = split /\s+/, MacPerl::Ask('Arguments?');
- }
-
-A MacPerl script saved as a "droplet" will populate C<@ARGV> with the full
-pathnames of the files dropped onto the script.
-
-Mac users can run programs under a type of command line interface
-under MPW (Macintosh Programmer's Workshop, a free development
-environment from Apple). MacPerl was first introduced as an MPW
-tool, and MPW can be used like a shell:
-
- perl myscript.plx some arguments
-
-ToolServer is another app from Apple that provides access to MPW tools
-from MPW and the MacPerl app, which allows MacPerl programs to use
-C<system>, backticks, and piped C<open>.
-
-"S<Mac OS>" is the proper name for the operating system, but the value
-in C<$^O> is "MacOS". To determine architecture, version, or whether
-the application or MPW tool version is running, check:
-
- $is_app = $MacPerl::Version =~ /App/;
- $is_tool = $MacPerl::Version =~ /MPW/;
- ($version) = $MacPerl::Version =~ /^(\S+)/;
- $is_ppc = $MacPerl::Architecture eq 'MacPPC';
- $is_68k = $MacPerl::Architecture eq 'Mac68K';
-
-S<Mac OS X>, based on NeXT's OpenStep OS, runs MacPerl natively, under the
-"Classic" environment. There is no "Carbon" version of MacPerl to run
-under the primary Mac OS X environment. S<Mac OS X> and its Open Source
-version, Darwin, both run Unix perl natively.
-
-Also see:
-
-=over 4
-
-=item *
-
-MacPerl Development, http://dev.macperl.org/ .
-
-=item *
-
-The MacPerl Pages, http://www.macperl.com/ .
-
-=item *
-
-The MacPerl mailing lists, http://lists.perl.org/ .
-
-=back
-
=head2 VMS
Perl on VMS is discussed in L<perlvms> in the perl distribution.
+
+The official name of VMS as of this writing is OpenVMS.
+
Perl on VMS can accept either VMS- or Unix-style file
specifications as in either of the following:
Do take care with C<$ ASSIGN/nolog/user SYS$COMMAND: SYS$INPUT> if your
perl-in-DCL script expects to do things like C<< $read = <STDIN>; >>.
-Filenames are in the format "name.extension;version". The maximum
-length for filenames is 39 characters, and the maximum length for
+The VMS operating system has two filesystems, known as ODS-2 and ODS-5.
+
+For ODS-2, filenames are in the format "name.extension;version". The
+maximum length for filenames is 39 characters, and the maximum length for
extensions is also 39 characters. Version is a number from 1 to
32767. Valid characters are C</[A-Z0-9$_-]/>.
-VMS's RMS filesystem is case-insensitive and does not preserve case.
-C<readdir> returns lowercased filenames, but specifying a file for
-opening remains case-insensitive. Files without extensions have a
-trailing period on them, so doing a C<readdir> with a file named F<A.;5>
-will return F<a.> (though that file could be opened with
+The ODS-2 filesystem is case-insensitive and does not preserve case.
+Perl simulates this by converting all filenames to lowercase internally.
+
+For ODS-5, filenames may have almost any character in them and can include
+Unicode characters. Characters that could be misinterpreted by the DCL
+shell or file parsing utilities need to be prefixed with the C<^>
+character, or replaced with hexadecimal characters prefixed with the
+C<^> character. Such prefixing is only needed with the pathnames are
+in VMS format in applications. Programs that can accept the Unix format
+of pathnames do not need the escape characters. The maximum length for
+filenames is 255 characters. The ODS-5 file system can handle both
+a case preserved and a case sensitive mode.
+
+ODS-5 is only available on the OpenVMS for 64 bit platforms.
+
+Support for the extended file specifications is being done as optional
+settings to preserve backward compatibility with Perl scripts that
+assume the previous VMS limitations.
+
+In general routines on VMS that get a Unix format file specification
+should return it in a Unix format, and when they get a VMS format
+specification they should return a VMS format unless they are documented
+to do a conversion.
+
+For routines that generate return a file specification, VMS allows setting
+if the C library which Perl is built on if it will be returned in VMS
+format or in Unix format.
+
+With the ODS-2 file system, there is not much difference in syntax of
+filenames without paths for VMS or Unix. With the extended character
+set available with ODS-5 there can be a significant difference.
+
+Because of this, existing Perl scripts written for VMS were sometimes
+treating VMS and Unix filenames interchangeably. Without the extended
+character set enabled, this behavior will mostly be maintained for
+backwards compatibility.
+
+When extended characters are enabled with ODS-5, the handling of
+Unix formatted file specifications is to that of a Unix system.
+
+VMS file specifications without extensions have a trailing dot. An
+equivalent Unix file specification should not show the trailing dot.
+
+The result of all of this, is that for VMS, for portable scripts, you
+can not depend on Perl to present the filenames in lowercase, to be
+case sensitive, and that the filenames could be returned in either
+Unix or VMS format.
+
+And if a routine returns a file specification, unless it is intended to
+convert it, it should return it in the same format as it found it.
+
+C<readdir> by default has traditionally returned lowercased filenames.
+When the ODS-5 support is enabled, it will return the exact case of the
+filename on the disk.
+
+Files without extensions have a trailing period on them, so doing a
+C<readdir> in the default mode with a file named F<A.;5> will
+return F<a.> when VMS is (though that file could be opened with
C<open(FH, 'A')>).
+With support for extended file specifications and if C<opendir> was
+given a Unix format directory, a file named F<A.;5> will return F<a>
+and optionally in the exact case on the disk. When C<opendir> is given
+a VMS format directory, then C<readdir> should return F<a.>, and
+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 "$_=~s/\s+.*//; print if scalar(split /\//) > 8;" < MANIFEST
+
The VMS::Filespec module, which gets installed as part of the build
process on VMS, is a pure Perl module that can easily be installed on
non-VMS platforms and can be helpful for conversions to and from RMS
-native formats.
+native formats. It is also now the only way that you should check to
+see if VMS is in a case sensitive mode.
What C<\n> represents depends on the type of file opened. It usually
represents C<\012> but it could also be C<\015>, C<\012>, C<\015\012>,
-C<\000>, C<\040>, or nothing depending on the file organiztion and
+C<\000>, C<\040>, or nothing depending on the file organization and
record format. The VMS::Stdio module provides access to the
special fopen() requirements of files with unusual attributes on VMS.
TCP/IP stacks are optional on VMS, so socket routines might not be
implemented. UDP sockets may not be supported.
+The TCP/IP library support for all current versions of VMS is dynamically
+loaded if present, so even if the routines are configured, they may
+return a status indicating that they are not implemented.
+
The value of C<$^O> on OpenVMS is "VMS". To determine the architecture
that you are running on without resorting to loading all of C<%Config>
you can examine the content of the C<@INC> array like so:
} elsif (grep(/VMS_VAX/, @INC)) {
print "I'm on VAX!\n";
+ } elsif (grep(/VMS_IA64/, @INC)) {
+ print "I'm on IA64!\n";
+
} else {
print "I'm not so sure about where $^O is...\n";
}
+In general, the significant differences should only be if Perl is running
+on VMS_VAX or one of the 64 bit OpenVMS platforms.
+
On VMS, perl determines the UTC offset from the C<SYS$TIMEZONE_DIFFERENTIAL>
logical name. Although the VMS epoch began at 17-NOV-1858 00:00:00.00,
calls to C<localtime> are adjusted to count offsets from
=item *
-F<README.vms> (installed as
L<README_vms>), L<perlvms>
+F<README.vms> (installed as
F<README_vms>), L<perlvms>
=item *
-vmsperl list, majordomo@perl.org
-
-(Put the words C<subscribe vmsperl> in message body.)
+vmsperl list, vmsperl-subscribe@perl.org
=item *
-vmsperl on the web, http://www.sidhe.org/vmsperl/index.html
+vmsperl on the web, L<http://www.sidhe.org/vmsperl/index.html>
=back
=head2 VOS
-Perl on VOS is discussed in F<README.vos> in the perl distribution
-(installed as L<perlvos>). Perl on VOS can accept either VOS- or
-Unix-style file specifications as in either of the following:
+Perl on VOS (also known as OpenVOS) is discussed in F<README.vos>
+in the perl distribution (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.
-
-The value of C<$^O> on VOS is "VOS". To determine the architecture that
-you are running on without resorting to loading all of C<%Config> you
-can examine the content of the @INC array like so:
+delimiting character, VOS files, directories, or links whose
+names contain a slash character cannot be processed. Such files
+must be renamed before they can be processed by Perl.
+
+Older releases of VOS (prior to OpenVOS Release 17.0) limit file
+names to 32 or fewer characters, prohibit file names from
+starting with a C<-> character, and prohibit file names from
+containing any character matching C<< tr/ !#%&'()*;<=>?// >>.
+
+Newer releases of VOS (OpenVOS Release 17.0 or later) support a
+feature known as extended names. On these releases, file names
+can contain up to 255 characters, are prohibited from starting
+with a C<-> character, and the set of prohibited characters is
+reduced to any character matching C<< tr/#%*<>?// >>. There are
+restrictions involving spaces and apostrophes: these characters
+must not begin or end a name, nor can they immediately precede or
+follow a period. Additionally, a space must not immediately
+precede another space or hyphen. Specifically, the following
+character combinations are prohibited: space-space,
+space-hyphen, period-space, space-period, period-apostrophe,
+apostrophe-period, leading or trailing space, and leading or
+trailing apostrophe. Although an extended file name is limited
+to 255 characters, a path name is still limited to 256
+characters.
+
+The value of C<$^O> on VOS is "VOS". To determine the
+architecture that you are running on without resorting to loading
+all of C<%Config> you can examine the content of the @INC array
+like so:
if ($^O =~ /VOS/) {
print "I'm on a Stratus box!\n";
The VOS mailing list.
There is no specific mailing list for Perl on VOS. You can post
-comments to the comp.sys.stratus newsgroup, or subscribe to the general
-Stratus mailing list. Send a letter with "subscribe Info-Stratus" in
-the message body to majordomo@list.stratagy.com.
+comments to the comp.sys.stratus newsgroup, or use the contact
+information located in the distribution files on the Stratus
+Anonymous FTP site.
=item *
-VOS Perl on the web at http://ftp.stratus.com/pub/vos/posix/posix.html
+VOS Perl on the web at L<http://ftp.stratus.com/pub/vos/posix/posix.html>
=back
Some simple tricks for determining if you are running on an EBCDIC
platform could include any of the following (perhaps all):
- if ("\t" eq "\05") { print "EBCDIC may be spoken here!\n"; }
+ if ("\t" eq "\005") { print "EBCDIC may be spoken here!\n"; }
if (ord('A') == 193) { print "EBCDIC may be spoken here!\n"; }
=item *
-*
-
L<perlos390>, F<README.os390>, F<perlbs2000>, F<README.vmesa>,
L<perlebcdic>.
general usage issues for all EBCDIC Perls. Send a message body of
"subscribe perl-mvs" to majordomo@perl.org.
-=item *
+=item *
AS/400 Perl information at
-http://as400.rochester.ibm.com/
+L<http://as400.rochester.ibm.com/>
as well as on CPAN in the F<ports/> directory.
=back
The Unix emulation library's translation of filenames to native assumes
that this sort of translation is required, and it allows a user-defined list
of known suffixes that it will transpose in this fashion. This may
-seem transparent, but consider that with these rules C<foo/bar/baz.h>
-and C<foo/bar/h/baz> both map to C<foo.bar.h.baz>, and that C<readdir> and
+seem transparent, but consider that with these rules F<foo/bar/baz.h>
+and F<foo/bar/h/baz> both map to F<foo.bar.h.baz>, and that C<readdir> and
C<glob> cannot and do not attempt to emulate the reverse mapping. Other
C<.>'s in filenames are translated to C</>.
=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
+L<http://www.bixby.org/mark/porting.html>
=item *
A free perl5-based PERL.NLM for Novell Netware is available in
-precompiled binary and source code form from http://www.novell.com/
+precompiled binary and source code form from L<http://www.novell.com/>
as well as from CPAN.
=item *
=over 8
-=item -X FILEHANDLE
-
-=item -X EXPR
-
=item -X
-C<-r>, C<-w>, and C<-x> have a limited meaning only; directories
-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<-s> returns the size of the data fork, not the total size of data fork
-plus resource fork. (S<Mac OS>).
-
C<-s> by name on an open file will return the space reserved on disk,
rather than the current extent. C<-s> on an open filehandle returns the
current size. (S<RISC OS>)
C<-R>, C<-W>, C<-X>, C<-O> are indistinguishable from C<-r>, C<-w>,
-C<-x>, C<-o>. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+C<-x>, C<-o>. (Win32, VMS, S<RISC OS>)
-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)
-C<-T> and C<-B> are implemented, but might misclassify Mac text files
-with foreign characters; this is the case will all platforms, but may
-affect S<Mac OS> often. (S<Mac OS>)
-
C<-x> (or C<-X>) determine if a file ends in one of the executable
suffixes. C<-S> is meaningless. (Win32)
C<-x> (or C<-X>) determine if a file has an executable file type.
(S<RISC OS>)
-=item alarm SECONDS
-
=item alarm
-Not implemented. (Win32)
+Emulated using timers that must be explicitly polled whenever Perl
+wants to dispatch "safe signals" and therefore cannot interrupt
+blocking system calls. (Win32)
+
+=item atan2
+
+Due to issues with various CPUs, math libraries, compilers, and standards,
+results for C<atan2()> may vary depending on any combination of the above.
+Perl attempts to conform to the Open Group/IEEE standards for the results
+returned from C<atan2()>, but cannot force the issue if the system Perl is
+run on does not allow it. (Tru64, HP-UX 10.20)
+
+The current version of the standards for C<atan2()> is available at
+L<http://www.opengroup.org/onlinepubs/009695399/functions/atan2.html>.
-=item binmode FILEHANDLE
+=item binmode
-Meaningless. (S<Mac OS>, S<RISC OS>)
+Meaningless. (S<RISC OS>)
Reopens file and restores pointer; if function fails, underlying
filehandle may be closed, or pointer may be in a different position.
The value returned by C<tell> may be affected after the call, and
the filehandle may be flushed. (Win32)
-=item chmod LIST
-
-Only limited meaning. Disabling/enabling write permission is mapped to
-locking/unlocking the file. (S<Mac OS>)
+=item chmod
Only good for changing "owner" read-write access, "group", and "other"
bits are meaningless. (Win32)
The actual permissions set depend on the value of the C<CYGWIN>
in the SYSTEM environment settings. (Cygwin)
-=item chown LIST
+=item chown
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>, S<RISC OS>)
+Not implemented. (Win32, S<Plan 9>, S<RISC OS>)
Does nothing, but won't fail. (Win32)
A little funky, because VOS's notion of ownership is a little funky (VOS).
-=item chroot FILENAME
-
=item chroot
-Not implemented. (
S<Mac OS>, Win32, VMS, S<Plan 9>, S<RISC OS>, VOS, VM/ESA)
+Not implemented. (Win32, VMS, S<Plan 9>, S<RISC OS>, VOS, VM/ESA)
-=item crypt PLAINTEXT,SALT
+=item crypt
May not be available if library or source was not provided when building
perl. (Win32)
-=item dbmclose HASH
+=item dbmclose
Not implemented. (VMS, S<Plan 9>, VOS)
-=item dbmopen HASH,DBNAME,MODE
+=item dbmopen
Not implemented. (VMS, S<Plan 9>, VOS)
-=item dump LABEL
+=item dump
-Not useful. (S<Mac OS>, S<RISC OS>)
+Not useful. (S<RISC OS>)
-Not implemented. (Win32)
+Not supported. (Cygwin, Win32)
Invokes VMS debugger. (VMS)
-=item exec LIST
-
-Not implemented. (S<Mac OS>)
+=item exec
Implemented via Spawn. (VM/ESA)
Does not automatically flush output handles on some platforms.
(SunOS, Solaris, HP-UX)
-=item exit EXPR
+Not supported. (Symbian OS)
=item exit
-Emulates UNIX exit() (which considers C<exit 1> to indicate an error) by
+Emulates Unix exit() (which considers C<exit 1> to indicate an error) by
mapping the C<1> to SS$_ABORT (C<44>). This behavior may be overridden
with the pragma C<use vmsish 'exit'>. As with the CRTL's exit()
function, C<exit 0> is also mapped to an exit status of SS$_NORMAL
(C<1>); this mapping cannot be overridden. Any other argument to exit()
-is used directly as Perl's exit status. (VMS)
+is used directly as Perl's exit status. On VMS, unless the future
+POSIX_EXIT mode is enabled, the exit code should always be a valid
+VMS exit code and not a generic number. When the POSIX_EXIT mode is
+enabled, a generic number will be encoded in a method compatible with
+the C library _POSIX_EXIT macro so that it can be decoded by other
+programs, particularly ones written in C, like the GNV package. (VMS)
-=item fcntl FILEHANDLE,FUNCTION,SCALAR
+C<exit()> resets file pointers, which is a problem when called
+from a child process (created by C<fork()>) in C<BEGIN>.
+A workaround is to use C<POSIX::_exit>. (Solaris)
-Not implemented. (Win32, VMS)
+ exit unless $Config{archname} =~ /\bsolaris\b/;
+ require POSIX and POSIX::_exit(0);
-=item flock FILEHANDLE,OPERATION
+=item fcntl
-Not implemented (S<Mac OS>, VMS, S<RISC OS>, VOS).
+Not implemented. (Win32)
-Available only on Windows NT (not on Windows 95). (Win32)
+Some functions available based on the version of VMS. (VMS)
+
+=item flock
+
+Not implemented (VMS, S<RISC OS>, VOS).
=item fork
-Not implemented. (S<Mac OS>, AmigaOS, S<RISC OS>, VM/ESA, VMS)
+Not implemented. (AmigaOS, S<RISC OS>, VM/ESA, VMS)
Emulated using multiple interpreters. See L<perlfork>. (Win32)
=item getlogin
-Not implemented. (S<Mac OS>, S<RISC OS>)
+Not implemented. (S<RISC OS>)
-=item getpgrp PID
+=item getpgrp
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (Win32, VMS, S<RISC OS>)
=item getppid
-Not implemented. (S<Mac OS>, Win32, S<RISC OS>)
+Not implemented. (Win32, S<RISC OS>)
-=item getpriority WHICH,WHO
+=item getpriority
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS, VM/ESA)
+Not implemented. (Win32, VMS, S<RISC OS>, VOS, VM/ESA)
-=item getpwnam NAME
+=item getpwnam
-Not implemented. (S<Mac OS>, Win32)
+Not implemented. (Win32)
Not useful. (S<RISC OS>)
-=item getgrnam NAME
+=item getgrnam
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (Win32, VMS, S<RISC OS>)
-=item getnetbyname NAME
+=item getnetbyname
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>)
+Not implemented. (Win32, S<Plan 9>)
-=item getpwuid UID
+=item getpwuid
-Not implemented. (S<Mac OS>, Win32)
+Not implemented. (Win32)
Not useful. (S<RISC OS>)
-=item getgrgid GID
+=item getgrgid
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
-
-=item getnetbyaddr ADDR,ADDRTYPE
-
-Not implemented. (S<Mac OS>, Win32, S<Plan 9>)
+Not implemented. (Win32, VMS, S<RISC OS>)
-=item getprotobynumber NUMBER
+=item getnetbyaddr
-Not implemented. (S<Mac OS>)
+Not implemented. (Win32, S<Plan 9>)
-=item getservbyport PORT,PROTO
+=item getprotobynumber
-Not implemented. (S<Mac OS>)
+=item getservbyport
=item getpwent
-Not implemented. (S<Mac OS>, Win32, VM/ESA)
+Not implemented. (Win32, VM/ESA)
=item getgrent
-Not implemented. (S<Mac OS>, Win32, VMS, VM/ESA)
+Not implemented. (Win32, VMS, VM/ESA)
=item gethostbyname
C<gethostbyname('localhost')> does not work everywhere: you may have
-to use C<gethostbyname('127.0.0.1')>. (S<Mac OS>, S<Irix 5>)
+to use C<gethostbyname('127.0.0.1')>. (S<Irix 5>)
=item gethostent
-Not implemented. (S<Mac OS>, Win32)
+Not implemented. (Win32)
=item getnetent
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>)
+Not implemented. (Win32, S<Plan 9>)
=item getprotoent
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>)
+Not implemented. (Win32, S<Plan 9>)
=item getservent
Not implemented. (Win32, S<Plan 9>)
-=item sethostent STAYOPEN
+=item sethostent
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>, S<RISC OS>)
+Not implemented. (Win32, S<Plan 9>, S<RISC OS>)
-=item setnetent STAYOPEN
+=item setnetent
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>, S<RISC OS>)
+Not implemented. (Win32, S<Plan 9>, S<RISC OS>)
-=item setprotoent STAYOPEN
+=item setprotoent
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>, S<RISC OS>)
+Not implemented. (Win32, S<Plan 9>, S<RISC OS>)
-=item setservent STAYOPEN
+=item setservent
Not implemented. (S<Plan 9>, Win32, S<RISC OS>)
=item endpwent
-Not implemented. (S<Mac OS>, MPE/iX, VM/ESA, Win32)
+Not implemented. (MPE/iX, VM/ESA, Win32)
=item endgrent
-Not implemented. (S<Mac OS>, MPE/iX, S<RISC OS>, VM/ESA, VMS, Win32)
+Not implemented. (MPE/iX, S<RISC OS>, VM/ESA, VMS, Win32)
=item endhostent
-Not implemented. (S<Mac OS>, Win32)
+Not implemented. (Win32)
=item endnetent
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>)
+Not implemented. (Win32, S<Plan 9>)
=item endprotoent
-Not implemented. (
S<Mac OS>, Win32, S<Plan 9>)
+Not implemented. (Win32, S<Plan 9>)
=item endservent
Not implemented. (S<Plan 9>)
-=item glob EXPR
-
=item glob
This operator is implemented via the File::Glob extension on most
platforms. See L<File::Glob> for portability information.
+=item gmtime
+
+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.
+
+On VOS, time values are 32-bit quantities.
+
=item ioctl FILEHANDLE,FUNCTION,SCALAR
Not implemented. (VMS)
Available only for socket handles. (S<RISC OS>)
-=item kill SIGNAL, LIST
-
-C<kill(0, LIST)> is implemented for the sake of taint checking;
-use with other signals is unimplemented. (S<Mac OS>)
+=item kill
Not implemented, hence not useful for taint checking. (S<RISC OS>)
$sig is 0 and the specified process exists, it returns true without
actually terminating it. (Win32)
-=item link OLDFILE,NEWFILE
+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)
+
+=item link
-Not implemented. (S<Mac OS>, MPE/iX, VMS, S<RISC OS>)
+Not implemented. (MPE/iX, S<RISC OS>, VOS)
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.
-=item lstat FILEHANDLE
+Available on 64 bit OpenVMS 8.2 and later. (VMS)
-=item lstat EXPR
+=item 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
-Not implemented. (VMS, S<RISC OS>)
+Not implemented. (S<RISC OS>)
Return values (especially for device and inode) may be bogus. (Win32)
-=item msgctl ID,CMD,ARG
-
-=item msgget KEY,FLAGS
+=item msgctl
-=item msgsnd ID,MSG,FLAGS
+=item msgget
-=item msgrcv ID,VAR,SIZE,TYPE,FLAGS
+=item msgsnd
-Not implemented. (S<Mac OS>, Win32, VMS, S<Plan 9>, S<RISC OS>, VOS)
+=item msgrcv
-=item open FILEHANDLE,EXPR
+Not implemented. (Win32, VMS, S<Plan 9>, S<RISC OS>, VOS)
-=item open FILEHANDLE
+=item open
-The C<|> variants are supported only if ToolServer is installed.
-(S<Mac OS>)
-
-open to C<|-> and C<-|> are unsupported. (S<Mac OS>, Win32, S<RISC OS>)
+open to C<|-> and C<-|> are unsupported. (Win32, S<RISC OS>)
Opening a process does not automatically flush output handles on some
platforms. (SunOS, Solaris, HP-UX)
-=item pipe READHANDLE,WRITEHANDLE
+=item readlink
+
+Not implemented. (Win32, VMS, S<RISC OS>)
-Very limited functionality. (MiNT)
+=item rename
-=item readlink EXPR
+Can't move directories between directories on different logical volumes. (Win32)
-=item readlink
+=item rewinddir
-Not implemented. (Win32, VMS, S<RISC OS>)
+Will not cause readdir() to re-read the directory stream. The entries
+already read before the rewinddir() call will just be returned again
+from a cache buffer. (Win32)
-=item select RBITS,WBITS,EBITS,TIMEOUT
+=item select
Only implemented on sockets. (Win32, VMS)
Note that the C<select FILEHANDLE> form is generally portable.
-=item semctl ID,SEMNUM,CMD,ARG
+=item semctl
-=item semget KEY,NSEMS,FLAGS
+=item semget
-=item semop KEY,OPSTRING
+=item semop
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
+Not implemented. (Win32, VMS, S<RISC OS>)
=item setgrent
-Not implemented. (S<Mac OS>, MPE/iX, VMS, Win32, S<RISC OS>, VOS)
+Not implemented. (MPE/iX, VMS, Win32, S<RISC OS>)
-=item setpgrp PID,PGRP
+=item setpgrp
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
+Not implemented. (Win32, VMS, S<RISC OS>, VOS)
-=item setpriority WHICH,WHO,PRIORITY
+=item setpriority
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
+Not implemented. (Win32, VMS, S<RISC OS>, VOS)
=item setpwent
-Not implemented. (S<Mac OS>, MPE/iX, Win32, S<RISC OS>, VOS)
+Not implemented. (MPE/iX, Win32, S<RISC OS>)
-=item setsockopt SOCKET,LEVEL,OPTNAME,OPTVAL
+=item setsockopt
Not implemented. (S<Plan 9>)
-=item shmctl ID,CMD,ARG
+=item shmctl
-=item shmget KEY,SIZE,FLAGS
+=item shmget
-=item shmread ID,VAR,POS,SIZE
+=item shmread
-=item shmwrite ID,STRING,POS,SIZE
+=item shmwrite
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
+Not implemented. (Win32, VMS, S<RISC OS>, VOS)
-=item sockatmark SOCKET
+=item sockatmark
A relatively recent addition to socket functions, may not
-be implemented even in UNIX platforms.
+be implemented even in Unix platforms.
-=item socketpair SOCKET1,SOCKET2,DOMAIN,TYPE,PROTOCOL
+=item socketpair
-Not implemented. (Win32, VMS, S<RISC OS>, VOS, VM/ESA)
+Not implemented. (S<RISC OS>, VM/ESA)
-=item stat FILEHANDLE
+Available on OpenVOS Release 17.0 or later. (VOS)
-=item stat EXPR
+Available on 64 bit OpenVMS 8.2 and later. (VMS)
=item stat
as '', so numeric comparison or manipulation of these fields may cause
'not numeric' warnings.
-mtime and atime are the same thing, and ctime is creation time instead of
-inode change time. (S<Mac OS>).
-
ctime not supported on UFS (S<Mac OS X>).
ctime is creation time instead of inode change time (Win32).
some versions of cygwin when doing a stat("foo") and if not finding it
may then attempt to stat("foo.exe") (Cygwin)
-=item symlink OLDFILE,NEWFILE
+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 ${^WIN32_SLOPPY_STAT} to a true value speeds up stat() by
+not performing this operation. (Win32)
-Not implemented. (Win32, VMS, S<RISC OS>)
+=item symlink
+
+Not implemented. (Win32, S<RISC OS>)
-=item syscall LIST
+Implemented on 64 bit VMS 8.3. VMS requires the symbolic link to be in Unix
+syntax if it is intended to resolve to a valid path.
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS, VM/ESA)
+=item syscall
-=item sysopen FILEHANDLE,FILENAME,MODE,PERMS
+Not implemented. (Win32, VMS, S<RISC OS>, VOS, VM/ESA)
+
+=item sysopen
The traditional "0", "1", and "2" MODEs are implemented with different
numeric values on some systems. The flags exported by C<Fcntl>
(O_RDONLY, O_WRONLY, O_RDWR) should work everywhere though. (S<Mac
OS>, OS/390, VM/ESA)
-=item system LIST
-
-In general, do not assume the UNIX/POSIX semantics that you can shift
-C<$?> right by eight to get the exit value, or that C<$? & 127>
-would give you the number of the signal that terminated the program,
-or that C<$? & 128> would test true if the program was terminated by a
-coredump. Instead, use the POSIX W*() interfaces: for example, use
-WIFEXITED($?) and WEXITVALUE($?) to test for a normal exit and the exit
-value, WIFSIGNALED($?) and WTERMSIG($?) for a signal exit and the
-signal. Core dumping is not a portable concept, so there's no portable
-way to test for that.
-
-Only implemented if ToolServer is installed. (S<Mac OS>)
+=item system
As an optimization, may not call the command shell specified in
C<$ENV{PERL5SHELL}>. C<system(1, @args)> spawns an external
I<scalar> will call the native command line direct and no such emulation
of a child Unix program will exists. Mileage B<will> vary. (S<RISC OS>)
-Far from being POSIX compliant. Because there may be no underlying
-/bin/sh tries to work around the problem by forking and execing the
-first token in its argument string. Handles basic redirection
-("<" or ">") on its own behalf. (MiNT)
-
Does not automatically flush output handles on some platforms.
(SunOS, Solaris, HP-UX)
The return value is POSIX-like (shifted up by 8 bits), which only allows
room for a made-up value derived from the severity bits of the native
32-bit condition code (unless overridden by C<use vmsish 'status'>).
+If the native condition code is one that has a POSIX value encoded, the
+POSIX value will be decoded to extract the expected exit value.
For more details see L<perlvms/$?>. (VMS)
=item times
-Only the first entry returned is nonzero. (S<Mac OS>)
-
"cumulative" times will be bogus. On anything other than Windows NT
or Windows 2000, "system" time will be bogus, and "user" time is
actually the time returned by the clock() function in the C runtime
Not useful. (S<RISC OS>)
-=item truncate FILEHANDLE,LENGTH
-
-=item truncate EXPR,LENGTH
+=item truncate
Not implemented. (Older versions of VMS)
or C<sysopen(FH,...,O_APPEND|O_RDWR)>. If a filename is supplied, it
should not be held open elsewhere. (Win32)
-=item umask EXPR
-
=item umask
Returns undef where unavailable, as of version 5.005.
C<umask> works but the correct permissions are set only when the file
is finally closed. (AmigaOS)
-=item utime LIST
+=item utime
-Only the modification time is updated. (S<BeOS>, S<Mac OS>, VMS, S<RISC OS>)
+Only the modification time is updated. (S<BeOS>, VMS, S<RISC OS>)
May not behave as expected. Behavior depends on the C runtime
library's implementation of utime(), and the filesystem being
=item wait
-=item waitpid PID,FLAGS
-
-Not implemented. (S<Mac OS>)
+=item waitpid
Can only be applied to process handles returned for processes spawned
using C<system(1, ...)> or pseudo processes created with C<fork()>. (Win32)
=back
-=head1 CHANGES
-=over 4
+=head1 Supported Platforms
-=item v1.49, 12 August 2002
+The following platforms are known to build Perl 5.12 (as of April 2010,
+its release date) from the standard source code distribution available
+at L<http://www.cpan.org/src>
-Updates for VOS from Paul Green.
+=over
-=item v1.48, 02 February 2001
+=item Linux (x86, ARM, IA64)
-Various updates from perl5-porters over the past year, supported
-platforms update from Jarkko Hietaniemi.
+=item HP-UX
-=item v1.47, 22 March 2000
+=item AIX
-Various cleanups from Tom Christiansen, including migration of
-long platform listings from L<perl>.
+=item Win32
-=item v1.46, 12 February 2000
+=over
-Updates for VOS and MPE/iX. (Peter Prymmer) Other small changes.
+=item Windows 2000
-=item v1.45, 20 December 1999
+=item Windows XP
-Small changes from 5.005_63 distribution, more changes to EBCDIC info.
+=item Windows Server 2003
-=item v1.44, 19 July 1999
+=item Windows Vista
-A bunch of updates from Peter Prymmer for C<$^O> values,
-endianness, File::Spec, VMS, BS2000, OS/400.
+=item Windows Server 2008
-=item v1.43, 24 May 1999
+=item Windows 7
-Added a lot of cleaning up from Tom Christiansen.
+=back
+
+=item Cygwin
+
+=item Solaris (x86, SPARC)
-=item v1.42, 22 May 1999
+=item OpenVMS
-Added notes about tests, sprintf/printf, and epoch offsets.
+=over
-=item v1.41, 19 May 1999
+=item Alpha (7.2 and later)
-Lots more little changes to formatting and content.
+=item I64 (8.2 and later)
-Added a bunch of C<$^O> and related values
-for various platforms; fixed mail and web addresses, and added
-and changed miscellaneous notes. (Peter Prymmer)
+=back
+
+=item Symbian
-=item v1.40, 11 April 1999
+=item NetBSD
-Miscellaneous changes.
+=item FreeBSD
-=item v1.39, 11 February 1999
+=item Debian GNU/kFreeBSD
-Changes from Jarkko and EMX URL fixes Michael Schwern. Additional
-note about newlines added.
+=item Haiku
-=item v1.38, 31 December 1998
+=item Irix (6.5. What else?)
-More changes from Jarkko.
+=item OpenBSD
-=item v1.37, 19 December 1998
+=item Dragonfly BSD
-More minor changes. Merge two separate version 1.35 documents.
+=item QNX Neutrino RTOS (6.5.0)
-=item v1.36, 9 September 1998
+=item MirOS BSD
-Updated for Stratus VOS. Also known as version 1.35.
+Caveats:
-=item v1.35, 13 August 1998
+=over
-Integrate more minor changes, plus addition of new sections under
-L<"ISSUES">: L<"Numbers endianness and Width">,
-L<"Character sets and character encoding">,
-L<"Internationalisation">.
+=item time_t issues that may or may not be fixed
-=item v1.33, 06 August 1998
+=back
+
+=item Symbian (Series 60 v3, 3.2 and 5 - what else?)
+
+=item Stratus VOS / OpenVOS
+
+=item AIX
+
+=back
-Integrate more minor changes.
+=head1 EOL Platforms (Perl 5.14)
-=item v1.32, 05 August 1998
+The following platforms were supported by a previous version of
+Perl but have been officially removed from Perl's source code
+as of 5.12:
-Integrate more minor changes.
+=over
-=item v1.30, 03 August 1998
+=item Atari MiNT
-Major update for RISC OS, other minor changes.
+=item Apollo Domain/OS
-=item v1.23, 10 July 1998
+=item Apple Mac OS 8/9
-First public release with perl5.005.
+=item Tenon Machten
=back
-=head1 Supported Platforms
+The following platforms were supported up to 5.10. They may still
+have worked in 5.12, but supporting code has been removed for 5.14:
+
+=over
+
+=item Windows 95
+
+=item Windows 98
+
+=item Windows ME
-As of July 2002 (the Perl release 5.8.0), the following platforms are
+=item Windows NT4
+
+=back
+
+=head1 Supported Platforms (Perl 5.8)
+
+As of July 2002 (the Perl release 5.8.0), the following platforms were
able to build Perl from the standard source code distribution
-available at http://www.cpan.org/src/index.html
+available at L<http://www.cpan.org/src/>
AIX
BeOS
ReliantUNIX (formerly SINIX)
OpenBSD
OpenVMS (formerly VMS)
- Open UNIX (formerly Unixware) (since Perl 5.8.1/5.9.0)
+ Open UNIX (Unixware) (since Perl 5.8.1/5.9.0)
OS/2
OS/400 (using the PASE) (since Perl 5.8.1/5.9.0)
PowerUX
Greenhills
ISC
MachTen 68k
- MiNT
MPC
NEWS-OS
NextSTEP
Unisys Dynix
The following platforms have their own source code distributions and
-binaries available via http://www.cpan.org/ports/
+binaries available via L<http://www.cpan.org/ports/>
Perl release
Tandem Guardian 5.004
The following platforms have only binaries available via
-http://www.cpan.org/ports/index.html :
+L<http://www.cpan.org/ports/index.html> :
Perl release
Although we do suggest that you always build your own Perl from
the source code, both for maximal configurability and for security,
in case you are in a hurry you can check
-http://www.cpan.org/ports/index.html for binary distributions.
+L<http://www.cpan.org/ports/index.html> for binary distributions.
=head1 SEE ALSO
-L<perlaix>, L<perlamiga>, L<perl
apollo>, L<perlbeos>, L<perlbs2000>,
+L<perlaix>, L<perlamiga>, 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<perlmac
hten>, L<perlmacos>, L<perlmint>, L<perlmpeix>,
+L<perlmac
os>, 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>,
Paul J. Schinder <schinder@pobox.com>,
Michael G Schwern <schwern@pobox.com>,
Dan Sugalski <dan@sidhe.org>,
-Nathan Torkington <gnat@frii.com>.
-
+Nathan Torkington <gnat@frii.com>,
+John Malmberg <wb8tyw@qsl.net>
https://perl5.git.perl.org / perl5.git / blobdiff