transient information about idiosyncrasies of some of the ports, almost
all of which are in a state of constant evolution. Thus, this material
should be considered a perpetual work in progress
-(E<lt>IMG SRC="yellow_sign.gif" ALT="Under Construction"E<gt>).
+(C<< <IMG SRC="yellow_sign.gif" ALT="Under Construction"> >>).
=head1 ISSUES
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 your reading or writing.
+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(/:/);
+ #...
+ }
+
+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().
+
+When dealing with binary files (or text files in binary mode) be sure
+to explicitly set $/ to the appropriate value for your file format
+before using chomp().
+
Because of the "text" mode translation, DOSish perls have limitations
in using C<seek> and C<tell> on a file accessed in "text" mode.
Stick to C<seek>-ing to locations you got from C<tell> (and no
Some of this may be confusing. Here's a handy reference to the ASCII CR
and LF characters. You can print it out and stick it in your wallet.
- LF == \012 == \x0A == \cJ == ASCII 10
- CR == \015 == \x0D == \cM == ASCII 13
+ LF eq \012 eq \x0A eq \cJ eq chr(10) eq ASCII 10
+ CR eq \015 eq \x0D eq \cM eq chr(13) eq ASCII 13
| Unix | DOS | Mac |
---------------------------
"\n", and "\n" on output becomes CRLF.
These are just the most common definitions of C<\n> and C<\r> in Perl.
-There may well be others.
+There may well be others. For example, on an EBCDIC implementation
+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 \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
+
+ | z/OS | OS/400 |
+ ----------------------
+ \n | LF | LF |
+ \r | CR | CR |
+ \n * | LF | LF |
+ \r * | CR | CR |
+ ----------------------
+ * text-mode STDIO
=head2 Numbers endianness and Width
Conflicting storage orders make utter mess out of the numbers. If a
little-endian host (Intel, VAX) stores 0x12345678 (305419896 in
-decimal), a big-endian host (Motorola, MIPS, Sparc, PA) reads it as
-0x78563412 (2018915346 in decimal). To avoid this problem in network
-(socket) connections use the C<pack> and C<unpack> formats C<n>
-and C<N>, the "network" orders. These are guaranteed to be portable.
+decimal), a big-endian host (Motorola, Sparc, PA) reads it as
+0x78563412 (2018915346 in decimal). Alpha and MIPS can be either:
+Digital/Compaq used/uses them in little-endian mode; SGI/Cray uses
+them in big-endian mode. To avoid this problem in network (socket)
+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:
either of the variables set like so:
$is_big_endian = unpack("h*", pack("s", 1)) =~ /01/;
- $is_litte_endian = unpack("h*", pack("s", 1)) =~ /^1/;
+ $is_little_endian = unpack("h*", pack("s", 1)) =~ /^1/;
Differing widths can cause truncation even between platforms of equal
endianness. The platform of shorter width loses the upper parts of the
One can circumnavigate both these problems in two ways. Either
transfer and store numbers always in text format, instead of raw
binary, or else consider using modules like Data::Dumper (included in
-the standard distribution as of Perl 5.005) and Storable. Keeping
-all data as text significantly simplifies matters.
+the standard distribution as of Perl 5.005) and Storable (included as
+of perl 5.8). Keeping all data as text significantly simplifies matters.
+
+The v-strings are portable only up to v2147483647 (0x7FFFFFFF), that's
+how far EBCDIC, or more precisely UTF-EBCDIC will go.
=head2 Files and Filesystems
notion of a "path" to uniquely identify a file on the system. How
that path is really written, though, differs considerably.
-Atlhough similar, file path specifications differ between Unix,
+Although similar, file path specifications differ between Unix,
Windows, S<Mac OS>, OS/2, VMS, VOS, S<RISC OS>, and probably others.
Unix, for example, is one of the few OSes that has the elegant idea
of a single root directory.
modification timestamp), or one second granularity of any timestamps
(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).
+
VOS perl can emulate Unix filenames with C</> as path separator. The
native pathname characters greater-than, less-than, number-sign, and
percent-sign are always accepted.
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,
+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
+layers usually try to make interfaces like chmod() work, but sometimes
+there simply is no good mapping.
+
If all this is intimidating, have no (well, maybe only a little)
fear. There are modules that can help. The File::Spec modules
provide methods to do the Right Thing on whatever platform happens
Don't assume a text file will end with a newline. They should,
but people forget.
-Do not have two files of the same name with different case, like
-F<test.pl> and F<Test.pl>, as many platforms have case-insensitive
-filenames. Also, try not to have non-word characters (except for C<.>)
-in the names, and keep them to the 8.3 convention, for maximum
-portability, onerous a burden though this may appear.
+Do not have two files or directories of the same name with different
+case, like F<test.pl> and F<Test.pl>, as many platforms have
+case-insensitive (or at least case-forgiving) filenames. Also, try
+not to have non-word characters (except for C<.>) in the names, and
+keep them to the 8.3 convention, for maximum portability, onerous a
+burden though this may appear.
Likewise, when using the AutoSplit module, try to keep your functions to
8.3 naming and case-insensitive conventions; or, at the least,
make it so the resulting files have a unique (case-insensitively)
first 8 characters.
-Whitespace in filenames is tolerated on most systems, but not all.
+Whitespace in filenames is tolerated on most systems, but not all,
+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.
-Don't assume C<E<gt>> won't be the first character of a filename.
-Always use C<E<lt>> explicitly to open a file for reading,
-unless you want the user to be able to specify a pipe open.
+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(FILE, '<', $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
-translate characters like C<E<gt>>, C<E<lt>>, and C<|>, which may
+translate characters like C<< > >>, C<< < >>, and C<|>, which may
be the wrong thing to do. (Sometimes, though, it's the right thing.)
+Three-arg open can also help protect against this translation in cases
+where it is undesirable.
+
+Don't use C<:> as a part of a filename since many systems use that for
+their own semantics (Mac OS Classic for separating pathname components,
+many networking schemes and utilities for separating the nodename and
+the pathname, and so on). For the same reasons, avoid C<@>, C<;> and
+C<|>.
+
+Don't assume that in pathnames you can collapse two leading slashes
+C<//> into one: some networking and clustering filesystems have special
+semantics for that. Let the operating system to sort it out.
+
+The I<portable filename characters> as defined by ANSI C are
+
+ a b c d e f g h i j k l m n o p q r t u v w x y z
+ A B C D E F G H I J K L M N O P Q R T U V W X Y Z
+ 0 1 2 3 4 5 6 7 8 9
+ . _ -
+
+and the "-" shouldn't be the first character. If you want to be
+hypercorrect, stay case-insensitive and within the 8.3 naming
+convention (all the files and directories have to be unique within one
+directory if their names are lowercased and truncated to eight
+characters before the C<.>, if any, and to three characters after the
+C<.>, if any). (And do not use C<.>s in directory names.)
=head2 System Interaction
not work everywhere. This is probably for the user of the program
to deal with, so don't stay up late worrying about it.
-Some platforms can't delete or rename files held open by the system.
-Remember to C<close> files when you are done with them. Don't
-C<unlink> or C<rename> an open file. Don't C<tie> or C<open> a
-file already tied or opened; C<untie> or C<close> it first.
+Some platforms can't delete or rename files held open by the system,
+this limitation may also apply to changing filesystem metainformation
+like file permissions or owners. Remember to C<close> files when you
+are done with them. Don't C<unlink> or C<rename> an open file. Don't
+C<tie> or C<open> a file already tied or opened; C<untie> or C<close>
+it first.
Don't open the same file more than once at a time for writing, as some
operating systems put mandatory locks on such files.
+Don't assume that write/modify permission on a directory gives the
+right to add or delete files/directories in that directory. That is
+filesystem specific: in some filesystems you need write/modify
+permission also (or even just) in the file/directory itself. In some
+filesystems (AFS, DFS) the permission to add/delete directory entries
+is a completely separate permission.
+
+Don't assume that a single C<unlink> completely gets rid of the file:
+some filesystems (most notably the ones in VMS) have versioned
+filesystems, and unlink() removes only the most recent one (it doesn't
+remove all the versions because by default the native tools on those
+platforms remove just the most recent version, too). The portable
+idiom to remove all the versions of a file is
+
+ 1 while unlink "file";
+
+This will terminate if the file is undeleteable for some reason
+(protected, not there, and so on).
+
Don't count on a specific environment variable existing in C<%ENV>.
Don't count on C<%ENV> entries being case-sensitive, or even
-case-preserving.
+case-preserving. Don't try to clear %ENV by saying C<%ENV = ();>, or,
+if you really have to, make it conditional on C<$^O ne 'VMS'> since in
+VMS the C<%ENV> table is much more than a per-process key-value string
+table.
Don't count on signals or C<%SIG> for anything.
Don't count on per-program environment variables, or per-program current
directories.
-Don't count on specific values of C<$!>.
+Don't count on specific values of C<$!>, neither numeric nor
+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<$!>
+at all except immediately after a failed system call.
+
+=head2 Command names versus file pathnames
+
+Don't assume that the name used to invoke a command or program with
+C<system> or C<exec> can also be used to test for the existence of the
+file that holds the executable code for that command or program.
+First, many systems have "internal" commands that are built-in to the
+shell or OS and while these commands can be invoked, there is no
+corresponding file. Second, some operating systems (e.g., Cygwin,
+DJGPP, OS/2, and VOS) have required suffixes for executable files;
+these suffixes are generally permitted on the command name but are not
+required. Thus, a command like "perl" might exist in a file named
+"perl", "perl.exe", or "perl.pm", depending on the operating system.
+The variable "_exe" in the Config module holds the executable suffix,
+if any. Third, the VMS port carefully sets up $^X and
+$Config{perlpath} so that no further processing is required. This is
+just as well, because the matching regular expression used below would
+then have to deal with a possible trailing version number in the VMS
+file name.
+
+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;}
+
+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;}
+
+=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
+things like 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)
most platforms (though many of them do not support any type of
forking). The problem with using them arises from what you invoke
them on. External tools are often named differently on different
-platforms, may not be available in the same location, migth accept
+platforms, may not be available in the same location, might accept
different arguments, can behave differently, and often present their
results in a platform-dependent way. Thus, you should seldom depend
on them to produce consistent results. (Then again, if you're calling
The Unix System V IPC (C<msg*(), sem*(), shm*()>) is not available
even on all Unix platforms.
+Do not use either the bare result of C<pack("N", 10, 20, 30, 40)> or
+bare v-strings (such as C<v10.20.30.40>) to represent IPv4 addresses:
+both forms just pack the four bytes into network order. That this
+would be equal to the C language C<in_addr> struct (which is what the
+socket code internally uses) is not guaranteed. To be portable use
+the routines of the Socket extension, such as C<inet_aton()>,
+C<inet_ntoa()>, and C<sockaddr_in()>.
+
The rule of thumb for portable code is: Do it all in portable Perl, or
use a module (that may internally implement it with platform-specific
code, but expose a common interface).
The system's notion of time of day and calendar date is controlled in
widely different ways. Don't assume the timezone is stored in C<$ENV{TZ}>,
and even if it is, don't assume that you can control the timezone through
-that variable.
+that variable. Don't assume anything about the three-letter timezone
+abbreviations (for example that MST would be the Mountain Standard Time,
+it's been known to stand for Moscow Standard Time). If you need to
+use timezones, express them in some unambiguous format like the
+exact number of minutes offset from UTC, or the POSIX timezone
+format.
Don't assume that the epoch starts at 00:00:00, January 1, 1970,
-because that is OS- and implementation-specific. It is better to store a date
-in an unambiguous representation. The ISO-8601 standard defines
-"YYYY-MM-DD" as the date format. A text representation (like "1987-12-18")
-can be easily converted into an OS-specific value using a module like
-Date::Parse. An array of values, such as those returned by
-C<localtime>, can be converted to an OS-specific representation using
-Time::Local.
+because that is OS- and implementation-specific. It is better to
+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
+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.
+An array of values, such as those returned by C<localtime>, can be
+converted to an OS-specific representation using Time::Local.
When calculating specific times, such as for tests in time or date modules,
it may be appropriate to calculate an offset for the epoch.
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 little about character sets. Assume nothing about
-numerical values (C<ord>, C<chr>) of characters. Do not
-assume that the alphabetic characters are encoded contiguously (in
-the numeric sense). 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'.
+Assume very little about character sets.
+
+Assume nothing about numerical values (C<ord>, C<chr>) of characters.
+Do not use explicit code point ranges (like \xHH-\xHH); use for
+example symbolic character classes like C<[:print:]>.
+
+Do not assume that the alphabetic characters are encoded contiguously
+(in the numeric sense). There may be gaps.
+
+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'.
=head2 Internationalisation
users. The system affects character sets and encoding, and date
and time formatting--amongst other things.
+If you really want to be international, you should consider Unicode.
+See L<perluniintro> and L<perlunicode> for more information.
+
+If you want to use non-ASCII bytes (outside the bytes 0x00..0x7f) in
+the "source code" of your code, to be portable you have to be explicit
+about what bytes they are. Someone might for example be using your
+code under a UTF-8 locale, in which case random native bytes might be
+illegal ("Malformed UTF-8 ...") This means that for example embedding
+ISO 8859-1 bytes beyond 0x7f into your strings might cause trouble
+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.
+
=head2 System Resources
If your code is destined for systems with severely constrained (or
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,
+not-- unfortunately. 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
+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
+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
+expect the C<< $< >> and C<< $> >> (or the C<$(> and C<$)>) to work
+for switching identities (or memberships).
+
+Don't assume set-uid and set-gid semantics. (And even if you do,
+think twice: set-uid and set-gid are a known can of security worms.)
+
=head2 Style
For those times when it is necessary to have platform-specific code,
Module code may be fully portable, but its tests might not be. This
often happens when tests spawn off other processes or call external
programs to aid in the testing, or when (as noted above) the tests
-assume certain things about the filesystem and paths. Be careful
-not to depend on a specific output style for errors, such as when
-checking C<$!> after an system call. Some platforms expect a certain
-output format, and perl on those platforms may have been adjusted
-accordingly. Most specifically, don't anchor a regex when testing
-an error value.
+assume certain things about the filesystem and paths. Be careful not
+to depend on a specific output style for errors, such as when checking
+C<$!> after a failed system call. Using C<$!> for anything else than
+displaying it as output is doubtful (though see the Errno module for
+testing reasonably portably for error value). Some platforms expect
+a certain output format, and Perl on those platforms may have been
+adjusted accordingly. Most specifically, don't anchor a regex when
+testing an error value.
=head1 CPAN Testers
=item Mailing list: cpan-testers@perl.org
-=item Testing results: C<http://www.perl.org/cpan-testers/>
+=item Testing results: http://testers.cpan.org/
=back
--------------------------------------------
AIX aix aix
BSD/OS bsdos i386-bsdos
+ Darwin darwin darwin
dgux dgux AViiON-dgux
DYNIX/ptx dynixptx i386-dynixptx
FreeBSD freebsd freebsd-i386
Linux linux ppc-linux
HP-UX hpux PA-RISC1.1
IRIX irix irix
- Mac OS X rhapsody rhapsody
+ Mac OS X darwin darwin
MachTen PPC machten powerpc-machten
NeXT 3 next next-fat
NeXT 4 next OPENSTEP-Mach
The C<$^O> variable and the C<$Config{archname}> values for various
DOSish perls are as follows:
- OS $^O $Config{'archname'}
- --------------------------------------------
- MS-DOS dos
- PC-DOS dos
- OS/2 os2
- Windows 95 MSWin32 MSWin32-x86
- Windows 98 MSWin32 MSWin32-x86
- Windows NT MSWin32 MSWin32-x86
- Windows NT MSWin32 MSWin32-ALPHA
- Windows NT MSWin32 MSWin32-ppc
+ OS $^O $Config{archname} ID Version
+ --------------------------------------------------------
+ MS-DOS dos ?
+ PC-DOS dos ?
+ OS/2 os2 ?
+ Windows 3.1 ? ? 0 3 01
+ Windows 95 MSWin32 MSWin32-x86 1 4 00
+ Windows 98 MSWin32 MSWin32-x86 1 4 10
+ Windows ME MSWin32 MSWin32-x86 1 ?
+ Windows NT MSWin32 MSWin32-x86 2 4 xx
+ Windows NT MSWin32 MSWin32-ALPHA 2 4 xx
+ Windows NT MSWin32 MSWin32-ppc 2 4 xx
+ Windows 2000 MSWin32 MSWin32-x86 2 5 xx
+ Windows XP MSWin32 MSWin32-x86 2 ?
+ Windows CE MSWin32 ? 3
+ Cygwin cygwin ?
+
+The various MSWin32 Perl's can distinguish the OS they are running on
+via the value of the fifth element of the list returned from
+Win32::GetOSVersion(). For example:
+
+ if ($^O eq 'MSWin32') {
+ my @os_version_info = Win32::GetOSVersion();
+ print +('3.1','95','NT')[$os_version_info[4]],"\n";
+ }
+
+There are also Win32::IsWinNT() and Win32::IsWin95(), try C<perldoc Win32>,
+and as of libwin32 0.19 (not part of the core Perl distribution)
+Win32::GetOSName(). The very portable POSIX::uname() will work too:
+
+ c:\> perl -MPOSIX -we "print join '|', uname"
+ Windows NT|moonru|5.0|Build 2195 (Service Pack 2)|x86
Also see:
=over 4
-=item The djgpp environment for DOS, C<http://www.delorie.com/djgpp/>
+=item *
+
+The djgpp environment for DOS, 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>.
+
+=item *
+
+Build instructions for Win32 in L<perlwin32>, or under the Cygnus environment
+in L<perlcygwin>.
-=item The EMX environment for DOS, OS/2, etc. C<emx@iaehv.nl>,
-C<http://www.leo.org/pub/comp/os/os2/leo/gnu/emx+gcc/index.html> or
-C<ftp://hobbes.nmsu.edu/pub/os2/dev/emx>
+=item *
-=item Build instructions for Win32, L<perlwin32>.
+The C<Win32::*> modules in L<Win32>.
-=item The ActiveState Pages, C<http://www.activestate.com/>
+=item *
-=item The Cygwin environment for Win32; L<README.cygwin>,
-C<http://sourceware.cygnus.com/cygwin/>
+The ActiveState Pages, http://www.activestate.com/
-=item The U/WIN environment for Win32,
-C<http://www.research.att.com/sw/tools/uwin/>
+=item *
+The Cygwin environment for Win32; F<README.cygwin> (installed
+as L<perlcygwin>), http://www.cygwin.com/
+
+=item *
+
+The U/WIN environment for Win32,
+http://www.research.att.com/sw/tools/uwin/
+
+=item *
+
+Build instructions for OS/2, L<perlos2>
=back
$is_ppc = $MacPerl::Architecture eq 'MacPPC';
$is_68k = $MacPerl::Architecture eq 'Mac68K';
-S<Mac OS X> and S<Mac OS X Server>, based on NeXT's OpenStep OS, will
-(in theory) be able to run MacPerl natively, under the "Classic"
-environment. The new "Cocoa" environment (formerly called the "Yellow Box")
-may run a slightly modified version of MacPerl, using the Carbon interfaces.
-
-S<Mac OS X Server> and its Open Source version, Darwin, both run Unix
-perl natively (with a few patches). Full support for these
-is slated for perl 5.6.
+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 The MacPerl Pages, C<http://www.macperl.com/>.
+=item *
-=item The MacPerl mailing lists, C<http://www.macperl.org/>.
+MacPerl Development, http://dev.macperl.org/ .
-=item MacPerl Module Porters, C<http://pudge.net/mmp/>.
+=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 F<vms/perlvms.pod> in the perl distribution.
+Perl on VMS is discussed in L<perlvms> in the perl distribution.
Perl on VMS can accept either VMS- or Unix-style file
specifications as in either of the following:
$ endif
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 = E<lt>STDINE<gt>;>.
+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
non-VMS platforms and can be helpful for conversions to and from RMS
native formats.
-What C<\n> represents depends on the type of file opened. It could
-be C<\015>, C<\012>, C<\015\012>, or nothing. The VMS::Stdio module
-provides access to the special fopen() requirements of files with unusual
-attributes on VMS.
+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 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.
=over 4
-=item L<README.vms>, L<perlvms.pod>
+=item *
+
+F<README.vms> (installed as L<README_vms>), L<perlvms>
+
+=item *
-=item vmsperl list, C<majordomo@perl.org>
+vmsperl list, majordomo@perl.org
-Put the words C<subscribe vmsperl> in message body.
+(Put the words C<subscribe vmsperl> in message body.)
-=item vmsperl on the web, C<http://www.sidhe.org/vmsperl/index.html>
+=item *
+
+vmsperl on the web, http://www.sidhe.org/vmsperl/index.html
=back
=head2 VOS
-Perl on VOS is discussed in F<README.vos> in the perl distribution.
-Perl on VOS can accept either VOS- or Unix-style file
-specifications as in either of the following:
+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 -ne "print if /perl_setup/i" >system>notices
- $ perl -ne "print if /perl_setup/i" /system/notices
+ C<< $ perl -ne "print if /perl_setup/i" >system>notices >>
+ C<< $ perl -ne "print if /perl_setup/i" /system/notices >>
or even a mixture of both as in:
- $ perl -ne "print if /perl_setup/i" >system/notices
+ C<< $ 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.
-
-The following C functions are unimplemented on VOS, and any attempt by
-Perl to use them will result in a fatal error message and an immediate
-exit from Perl: dup, do_aspawn, do_spawn, fork, waitpid. Once these
-functions become available in the VOS POSIX.1 implementation, you can
-either recompile and rebind Perl, or you can download a newer port from
-ftp.stratus.com.
+renamed before they can be processed by Perl. Note that VOS limits
+file names to 32 or fewer characters.
The value of C<$^O> on VOS is "VOS". To determine the architecture that
you are running on without resorting to loading all of C<%Config> you
-can examine the content of the C<@INC> array like so:
+can examine the content of the @INC array like so:
- if (grep(/VOS/, @INC)) {
+ if ($^O =~ /VOS/) {
print "I'm on a Stratus box!\n";
} else {
print "I'm not on a Stratus box!\n";
die;
}
- if (grep(/860/, @INC)) {
- print "This box is a Stratus XA/R!\n";
-
- } elsif (grep(/7100/, @INC)) {
- print "This box is a Stratus HP 7100 or 8000!\n";
-
- } elsif (grep(/8000/, @INC)) {
- print "This box is a Stratus HP 8000!\n";
-
- } else {
- print "This box is a Stratus 68K...\n";
- }
-
Also see:
=over 4
-=item L<README.vos>
+=item *
-=item VOS mailing list
+F<README.vos> (installed as L<perlvos>)
+
+=item *
+
+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
+Stratus mailing list. Send a letter with "subscribe Info-Stratus" in
the message body to majordomo@list.stratagy.com.
-=item VOS Perl on the web at C<http://ftp.stratus.com/pub/vos/vos.html>
+=item *
+
+VOS Perl on the web at http://ftp.stratus.com/pub/vos/posix/posix.html
=back
Recent versions of Perl have been ported to platforms such as OS/400 on
AS/400 minicomputers as well as OS/390, VM/ESA, and BS2000 for S/390
Mainframes. Such computers use EBCDIC character sets internally (usually
-Character Code Set ID 00819 for OS/400 and 1047 for S/390 systems).
-On the mainframe perl currently works under the "Unix system services
-for OS/390" (formerly known as OpenEdition), VM/ESA OpenEdition, or
-the BS200 POSIX system (BS2000 is supported in perl 5.006 and greater).
+Character Code Set ID 0037 for OS/400 and either 1047 or POSIX-BC for S/390
+systems). On the mainframe perl currently works under the "Unix system
+services for OS/390" (formerly known as OpenEdition), VM/ESA OpenEdition, or
+the BS200 POSIX-BC system (BS2000 is supported in perl 5.6 and greater).
+See L<perlos390> for details. Note that for OS/400 there is also a port of
+Perl 5.8.1/5.9.0 or later to the PASE which is ASCII-based (as opposed to
+ILE which is EBCDIC-based), see L<perlos400>.
As of R2.5 of USS for OS/390 and Version 2.3 of VM/ESA these Unix
sub-systems do not support the C<#!> shebang trick for script invocation.
=over 4
-=item L<README.os390>, L<README.posix-bc>, L<README.vmesa>
+=item *
+
+*
+
+L<perlos390>, F<README.os390>, F<perlbs2000>, F<README.vmesa>,
+L<perlebcdic>.
-=item perl-mvs list
+=item *
The perl-mvs@perl.org list is for discussion of porting issues as well as
general usage issues for all EBCDIC Perls. Send a message body of
"subscribe perl-mvs" to majordomo@perl.org.
-=item AS/400 Perl information at C<http://as400.rochester.ibm.com/>
+=item *
+
+AS/400 Perl information at
+http://as400.rochester.ibm.com/
as well as on CPAN in the F<ports/> directory.
=back
Writing to a new file C<System:Modules> would be allowed only if
C<System$Path> contains a single item list. The filesystem will also
expand system variables in filenames if enclosed in angle brackets, so
-C<E<lt>System$DirE<gt>.Modules> would look for the file
+C<< <System$Dir>.Modules >> would look for the file
S<C<$ENV{'System$Dir'} . 'Modules'>>. The obvious implication of this is
-that B<fully qualified filenames can start with C<E<lt>E<gt>>> and should
+that B<fully qualified filenames can start with C<< <> >>> and should
be protected when C<open> is used for input.
Because C<.> was in use as a directory separator and filenames could not
passing C<STDIN>, C<STDOUT>, or C<STDERR> to your children.
The desire of users to express filenames of the form
-C<E<lt>Foo$DirE<gt>.Bar> on the command line unquoted causes problems,
+C<< <Foo$Dir>.Bar >> on the command line unquoted causes problems,
too: C<``> command output capture has to perform a guessing game. It
-assumes that a string C<E<lt>[^E<lt>E<gt>]+\$[^E<lt>E<gt>]E<gt>> is a
+assumes that a string C<< <[^<>]+\$[^<>]> >> is a
reference to an environment variable, whereas anything else involving
-C<E<lt>> or C<E<gt>> is redirection, and generally manages to be 99%
+C<< < >> or C<< > >> is redirection, and generally manages to be 99%
right. Of course, the problem remains that scripts cannot rely on any
Unix tools being available, or that any tools found have Unix-like command
line arguments.
OS $^O $Config{'archname'}
------------------------------------------
Amiga DOS amigaos m68k-amigos
+ BeOS beos
MPE/iX mpeix PA-RISC1.1
See also:
=over 4
-=item Amiga, L<README.amiga>
+=item *
+
+Amiga, F<README.amiga> (installed as L<perlamiga>).
+
+=item *
+
+Atari, F<README.mint> and Guido Flohr's web page
+http://stud.uni-sb.de/~gufl0000/
+
+=item *
-=item Atari, L<README.mint> and Guido Flohr's web page
-C<http://stud.uni-sb.de/~gufl0000/>
+Be OS, F<README.beos>
-=item Be OS, L<README.beos>
+=item *
-=item HP 300 MPE/iX, L<README.mpeix> and Mark Bixby's web page
-C<http://www.cccd.edu/~markb/perlix.html>
+HP 300 MPE/iX, F<README.mpeix> and Mark Bixby's web page
+http://www.bixby.org/mark/perlix.html
-=item Novell Netware
+=item *
A free perl5-based PERL.NLM for Novell Netware is available in
-precompiled binary and source code form from C<http://www.novell.com/>
+precompiled binary and source code form from http://www.novell.com/
as well as from CPAN.
-=item Plan 9, L<README.plan9>
+=item *
+
+S<Plan 9>, F<README.plan9>
=back
Access permissions are mapped onto VOS access-control list changes. (VOS)
+The actual permissions set depend on the value of the C<CYGWIN>
+in the SYSTEM environment settings. (Cygwin)
+
=item chown LIST
-Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>, VOS)
+Not implemented. (S<Mac OS>, 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, Plan9, S<RISC OS>, VOS, VM/ESA)
+Not implemented. (S<Mac OS>, Win32, VMS, S<Plan 9>, S<RISC OS>, VOS, VM/ESA)
=item crypt PLAINTEXT,SALT
May not be available if library or source was not provided when building
perl. (Win32)
-Not implemented. (VOS)
-
=item dbmclose HASH
-Not implemented. (VMS, Plan9, VOS)
+Not implemented. (VMS, S<Plan 9>, VOS)
=item dbmopen HASH,DBNAME,MODE
-Not implemented. (VMS, Plan9, VOS)
+Not implemented. (VMS, S<Plan 9>, VOS)
=item dump LABEL
Implemented via Spawn. (VM/ESA)
+Does not automatically flush output handles on some platforms.
+(SunOS, Solaris, HP-UX)
+
+=item exit EXPR
+
+=item exit
+
+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)
+
=item fcntl FILEHANDLE,FUNCTION,SCALAR
Not implemented. (Win32, VMS)
=item fork
-Not implemented. (S<Mac OS>, Win32, AmigaOS, S<RISC OS>, VOS, VM/ESA)
+Not implemented. (S<Mac OS>, AmigaOS, S<RISC OS>, VM/ESA, VMS)
+
+Emulated using multiple interpreters. See L<perlfork>. (Win32)
+
+Does not automatically flush output handles on some platforms.
+(SunOS, Solaris, HP-UX)
=item getlogin
=item getpgrp PID
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
=item getppid
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, S<RISC OS>)
=item getpriority WHICH,WHO
=item getnetbyname NAME
-Not implemented. (S<Mac OS>, Win32, Plan9)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>)
=item getpwuid UID
=item getnetbyaddr ADDR,ADDRTYPE
-Not implemented. (S<Mac OS>, Win32, Plan9)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>)
=item getprotobynumber NUMBER
Not implemented. (S<Mac OS>, 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>)
+
=item gethostent
Not implemented. (S<Mac OS>, Win32)
=item getnetent
-Not implemented. (S<Mac OS>, Win32, Plan9)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>)
=item getprotoent
-Not implemented. (S<Mac OS>, Win32, Plan9)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>)
=item getservent
-Not implemented. (Win32, Plan9)
-
-=item setpwent
-
-Not implemented. (S<Mac OS>, Win32, S<RISC OS>)
-
-=item setgrent
-
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (Win32, S<Plan 9>)
=item sethostent STAYOPEN
-Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>, S<RISC OS>)
=item setnetent STAYOPEN
-Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>, S<RISC OS>)
=item setprotoent STAYOPEN
-Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>, S<RISC OS>)
=item setservent STAYOPEN
-Not implemented. (Plan9, Win32, S<RISC OS>)
+Not implemented. (S<Plan 9>, Win32, S<RISC OS>)
=item endpwent
-Not implemented. (S<Mac OS>, Win32, VM/ESA)
+Not implemented. (S<Mac OS>, MPE/iX, VM/ESA, Win32)
=item endgrent
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VM/ESA)
+Not implemented. (S<Mac OS>, MPE/iX, S<RISC OS>, VM/ESA, VMS, Win32)
=item endhostent
=item endnetent
-Not implemented. (S<Mac OS>, Win32, Plan9)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>)
=item endprotoent
-Not implemented. (S<Mac OS>, Win32, Plan9)
+Not implemented. (S<Mac OS>, Win32, S<Plan 9>)
=item endservent
-Not implemented. (Plan9, Win32)
+Not implemented. (S<Plan 9>, Win32)
=item getsockopt SOCKET,LEVEL,OPTNAME
-Not implemented. (S<Mac OS>, Plan9)
+Not implemented. (S<Plan 9>)
=item glob EXPR
=item glob
-Globbing built-in, but only C<*> and C<?> metacharacters are supported.
-(S<Mac OS>)
-
-Features depend on external perlglob.exe or perlglob.bat. May be
-overridden with something like File::DosGlob, which is recommended.
-(Win32)
-
-Globbing built-in, but only C<*> and C<?> metacharacters are supported.
-Globbing relies on operating system calls, which may return filenames
-in any order. As most filesystems are case-insensitive, even "sorted"
-filenames will not be in case-sensitive order. (S<RISC OS>)
+This operator is implemented via the File::Glob extension on most
+platforms. See L<File::Glob> for portability information.
=item ioctl FILEHANDLE,FUNCTION,SCALAR
=item kill SIGNAL, LIST
-Not implemented, hence not useful for taint checking. (S<Mac OS>,
-S<RISC OS>)
+C<kill(0, LIST)> is implemented for the sake of taint checking;
+use with other signals is unimplemented. (S<Mac OS>)
-Unlike Unix platforms, C<kill(0, $pid)> will actually terminate
-the process. (Win32)
+Not implemented, hence not useful for taint checking. (S<RISC OS>)
+
+C<kill()> doesn't have the semantics of C<raise()>, i.e. it doesn't send
+a signal to the identified process like it does on Unix platforms.
+Instead C<kill($sig, $pid)> terminates the process identified by $pid,
+and makes it exit immediately with exit status $sig. As in Unix, if
+$sig is 0 and the specified process exists, it returns true without
+actually terminating it. (Win32)
=item link OLDFILE,NEWFILE
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, MPE/iX, VMS, S<RISC OS>)
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.
+
=item lstat FILEHANDLE
=item lstat EXPR
Not implemented. (VMS, S<RISC OS>)
-Return values may be bogus. (Win32)
+Return values (especially for device and inode) may be bogus. (Win32)
=item msgctl ID,CMD,ARG
=item msgrcv ID,VAR,SIZE,TYPE,FLAGS
-Not implemented. (S<Mac OS>, Win32, VMS, Plan9, S<RISC OS>, VOS)
+Not implemented. (S<Mac OS>, Win32, VMS, S<Plan 9>, S<RISC OS>, VOS)
=item open FILEHANDLE,EXPR
open to C<|-> and C<-|> are unsupported. (S<Mac OS>, Win32, S<RISC OS>)
-=item pipe READHANDLE,WRITEHANDLE
+Opening a process does not automatically flush output handles on some
+platforms. (SunOS, Solaris, HP-UX)
-Not implemented. (S<Mac OS>)
+=item pipe READHANDLE,WRITEHANDLE
Very limited functionality. (MiNT)
=item select RBITS,WBITS,EBITS,TIMEOUT
-Only implemented on sockets. (Win32)
+Only implemented on sockets. (Win32, VMS)
Only reliable on sockets. (S<RISC OS>)
+Note that the C<select FILEHANDLE> form is generally portable.
+
=item semctl ID,SEMNUM,CMD,ARG
=item semget KEY,NSEMS,FLAGS
Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
+=item setgrent
+
+Not implemented. (S<Mac OS>, MPE/iX, VMS, Win32, S<RISC OS>, VOS)
+
=item setpgrp PID,PGRP
Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
+=item setpwent
+
+Not implemented. (S<Mac OS>, MPE/iX, Win32, S<RISC OS>, VOS)
+
=item setsockopt SOCKET,LEVEL,OPTNAME,OPTVAL
-Not implemented. (S<Mac OS>, Plan9)
+Not implemented. (S<Plan 9>)
=item shmctl ID,CMD,ARG
Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
+=item sockatmark SOCKET
+
+A relatively recent addition to socket functions, may not
+be implemented even in UNIX platforms.
+
=item socketpair SOCKET1,SOCKET2,DOMAIN,TYPE,PROTOCOL
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS, VM/ESA)
+Not implemented. (Win32, VMS, S<RISC OS>, VOS, VM/ESA)
=item stat FILEHANDLE
=item stat
+Platforms that do not have rdev, blksize, or blocks will return these
+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>)
+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).
device and inode are not meaningful. (Win32)
mtime, atime and ctime all return the last modification time. Device and
inode are not necessarily reliable. (S<RISC OS>)
+dev, rdev, blksize, and blocks are not available. inode is not
+meaningful and will differ between stat calls on the same file. (os2)
+
+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
Not implemented. (Win32, VMS, S<RISC OS>)
=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($?) for a signal exit and the
+signal. Core dumping is not a portable concept, so there's no portable
+way to test for that.
+
Only implemented if ToolServer is installed. (S<Mac OS>)
As an optimization, may not call the command shell specified in
C<$ENV{PERL5SHELL}>. C<system(1, @args)> spawns an external
process and immediately returns its process designator, without
waiting for it to terminate. Return value may be used subsequently
-in C<wait> or C<waitpid>. (Win32)
+in C<wait> or C<waitpid>. Failure to spawn() a subprocess is indicated
+by setting $? to "255 << 8". C<$?> is set in a way compatible with
+Unix (i.e. the exitstatus of the subprocess is obtained by "$? >> 8",
+as described in the documentation). (Win32)
There is no shell to process metacharacters, and the native standard is
to pass a command line terminated by "\n" "\r" or "\0" to the spawned
-program. Redirection such as C<E<gt> foo> is performed (if at all) by
+program. Redirection such as C<< > foo >> is performed (if at all) by
the run time library of the spawned program. C<system> I<list> will call
the Unix emulation library's C<exec> emulation, which attempts to provide
emulation of the stdin, stdout, stderr in force in the parent, providing
Far from being POSIX compliant. Because there may be no underlying
/bin/sh tries to work around the problem by forking and execing the
first token in its argument string. Handles basic redirection
-("E<lt>" or "E<gt>") on its own behalf. (MiNT)
+("<" or ">") on its own behalf. (MiNT)
+
+Does not automatically flush output handles on some platforms.
+(SunOS, Solaris, HP-UX)
+
+The return value is POSIX-like (shifted up by 8 bits), which only allows
+room for a made-up value derived from the severity bits of the native
+32-bit condition code (unless overridden by C<use vmsish 'status'>).
+For more details see L<perlvms/$?>. (VMS)
=item times
Only the first entry returned is nonzero. (S<Mac OS>)
-"cumulative" times will be bogus. On anything other than Windows NT,
-"system" time will be bogus, and "user" time is actually the time
-returned by the clock() function in the C runtime library. (Win32)
+"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
+library. (Win32)
Not useful. (S<RISC OS>)
=item truncate EXPR,LENGTH
-Not implemented. (VMS)
+Not implemented. (Older versions of VMS)
-Truncation to zero-length only. (VOS)
+Truncation to same-or-shorter lengths only. (VOS)
If a FILEHANDLE is supplied, it must be writable and opened in append
-mode (i.e., use C<open(FH, '>>filename')>
+mode (i.e., use C<<< open(FH, '>>filename') >>>
or C<sysopen(FH,...,O_APPEND|O_RDWR)>. If a filename is supplied, it
should not be held open elsewhere. (Win32)
=item utime LIST
-Only the modification time is updated. (S<Mac OS>, VMS, S<RISC OS>)
+Only the modification time is updated. (S<BeOS>, S<Mac OS>, 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 waitpid PID,FLAGS
-Not implemented. (S<Mac OS>, VOS)
+Not implemented. (S<Mac OS>)
Can only be applied to process handles returned for processes spawned
-using C<system(1, ...)>. (Win32)
+using C<system(1, ...)> or pseudo processes created with C<fork()>. (Win32)
Not useful. (S<RISC OS>)
=over 4
+=item v1.49, 12 August 2002
+
+Updates for VOS from Paul Green.
+
+=item v1.48, 02 February 2001
+
+Various updates from perl5-porters over the past year, supported
+platforms update from Jarkko Hietaniemi.
+
+=item v1.47, 22 March 2000
+
+Various cleanups from Tom Christiansen, including migration of
+long platform listings from L<perl>.
+
+=item v1.46, 12 February 2000
+
+Updates for VOS and MPE/iX. (Peter Prymmer) Other small changes.
+
+=item v1.45, 20 December 1999
+
+Small changes from 5.005_63 distribution, more changes to EBCDIC info.
+
=item v1.44, 19 July 1999
A bunch of updates from Peter Prymmer for C<$^O> values,
=back
+=head1 Supported Platforms
+
+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
+
+ AIX
+ BeOS
+ BSD/OS (BSDi)
+ Cygwin
+ DG/UX
+ DOS DJGPP 1)
+ DYNIX/ptx
+ EPOC R5
+ FreeBSD
+ HI-UXMPP (Hitachi) (5.8.0 worked but we didn't know it)
+ HP-UX
+ IRIX
+ Linux
+ Mac OS Classic
+ Mac OS X (Darwin)
+ MPE/iX
+ NetBSD
+ NetWare
+ NonStop-UX
+ ReliantUNIX (formerly SINIX)
+ OpenBSD
+ OpenVMS (formerly VMS)
+ 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
+ POSIX-BC (formerly BS2000)
+ QNX
+ Solaris
+ SunOS 4
+ SUPER-UX (NEC)
+ Tru64 UNIX (formerly DEC OSF/1, Digital UNIX)
+ UNICOS
+ UNICOS/mk
+ UTS
+ VOS
+ Win95/98/ME/2K/XP 2)
+ WinCE
+ z/OS (formerly OS/390)
+ VM/ESA
+
+ 1) in DOS mode either the DOS or OS/2 ports can be used
+ 2) compilers: Borland, MinGW (GCC), VC6
+
+The following platforms worked with the previous releases (5.6 and
+5.7), but we did not manage either to fix or to test these in time
+for the 5.8.0 release. There is a very good chance that many of these
+will work fine with the 5.8.0.
+
+ BSD/OS
+ DomainOS
+ Hurd
+ LynxOS
+ MachTen
+ PowerMAX
+ SCO SV
+ SVR4
+ Unixware
+ Windows 3.1
+
+Known to be broken for 5.8.0 (but 5.6.1 and 5.7.2 can be used):
+
+ AmigaOS
+
+The following platforms have been known to build Perl from source in
+the past (5.005_03 and earlier), but we haven't been able to verify
+their status for the current release, either because the
+hardware/software platforms are rare or because we don't have an
+active champion on these platforms--or both. They used to work,
+though, so go ahead and try compiling them, and let perlbug@perl.org
+of any trouble.
+
+ 3b1
+ A/UX
+ ConvexOS
+ CX/UX
+ DC/OSx
+ DDE SMES
+ DOS EMX
+ Dynix
+ EP/IX
+ ESIX
+ FPS
+ GENIX
+ Greenhills
+ ISC
+ MachTen 68k
+ MiNT
+ MPC
+ NEWS-OS
+ NextSTEP
+ OpenSTEP
+ Opus
+ Plan 9
+ RISC/os
+ SCO ODT/OSR
+ Stellar
+ SVR2
+ TI1500
+ TitanOS
+ Ultrix
+ Unisys Dynix
+
+The following platforms have their own source code distributions and
+binaries available via http://www.cpan.org/ports/
+
+ Perl release
+
+ OS/400 (ILE) 5.005_02
+ Tandem Guardian 5.004
+
+The following platforms have only binaries available via
+http://www.cpan.org/ports/index.html :
+
+ Perl release
+
+ Acorn RISCOS 5.005_02
+ AOS 5.002
+ LynxOS 5.004_02
+
+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.
+
+=head1 SEE ALSO
+
+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<perlnetware>, L<perlos2>, L<perlos390>, L<perlos400>,
+L<perlplan9>, L<perlqnx>, L<perlsolaris>, L<perltru64>,
+L<perlunicode>, L<perlvmesa>, L<perlvms>, L<perlvos>,
+L<perlwin32>, and L<Win32>.
+
=head1 AUTHORS / CONTRIBUTORS
-Abigail E<lt>abigail@fnx.comE<gt>,
-Charles Bailey E<lt>bailey@newman.upenn.eduE<gt>,
-Graham Barr E<lt>gbarr@pobox.comE<gt>,
-Tom Christiansen E<lt>tchrist@perl.comE<gt>,
-Nicholas Clark E<lt>Nicholas.Clark@liverpool.ac.ukE<gt>,
-Thomas Dorner E<lt>Thomas.Dorner@start.deE<gt>,
-Andy Dougherty E<lt>doughera@lafcol.lafayette.eduE<gt>,
-Dominic Dunlop E<lt>domo@vo.luE<gt>,
-Neale Ferguson E<lt>neale@mailbox.tabnsw.com.auE<gt>,
-David J. Fiander E<lt>davidf@mks.comE<gt>,
-Paul Green E<lt>Paul_Green@stratus.comE<gt>,
-M.J.T. Guy E<lt>mjtg@cus.cam.ac.ukE<gt>,
-Jarkko Hietaniemi E<lt>jhi@iki.fi<gt>,
-Luther Huffman E<lt>lutherh@stratcom.comE<gt>,
-Nick Ing-Simmons E<lt>nick@ni-s.u-net.comE<gt>,
-Andreas J. KE<ouml>nig E<lt>koenig@kulturbox.deE<gt>,
-Markus Laker E<lt>mlaker@contax.co.ukE<gt>,
-Andrew M. Langmead E<lt>aml@world.std.comE<gt>,
-Larry Moore E<lt>ljmoore@freespace.netE<gt>,
-Paul Moore E<lt>Paul.Moore@uk.origin-it.comE<gt>,
-Chris Nandor E<lt>pudge@pobox.comE<gt>,
-Matthias Neeracher E<lt>neeri@iis.ee.ethz.chE<gt>,
-Gary Ng E<lt>71564.1743@CompuServe.COME<gt>,
-Tom Phoenix E<lt>rootbeer@teleport.comE<gt>,
-Peter Prymmer E<lt>pvhp@forte.comE<gt>,
-Hugo van der Sanden E<lt>hv@crypt0.demon.co.ukE<gt>,
-Gurusamy Sarathy E<lt>gsar@activestate.comE<gt>,
-Paul J. Schinder E<lt>schinder@pobox.comE<gt>,
-Michael G Schwern E<lt>schwern@pobox.comE<gt>,
-Dan Sugalski E<lt>sugalskd@ous.eduE<gt>,
-Nathan Torkington E<lt>gnat@frii.comE<gt>.
-
-This document is maintained by Chris Nandor
-E<lt>pudge@pobox.comE<gt>.
-
-=head1 VERSION
-
-Version 1.44, last modified 22 July 1999
+Abigail <abigail@foad.org>,
+Charles Bailey <bailey@newman.upenn.edu>,
+Graham Barr <gbarr@pobox.com>,
+Tom Christiansen <tchrist@perl.com>,
+Nicholas Clark <nick@ccl4.org>,
+Thomas Dorner <Thomas.Dorner@start.de>,
+Andy Dougherty <doughera@lafayette.edu>,
+Dominic Dunlop <domo@computer.org>,
+Neale Ferguson <neale@vma.tabnsw.com.au>,
+David J. Fiander <davidf@mks.com>,
+Paul Green <Paul.Green@stratus.com>,
+M.J.T. Guy <mjtg@cam.ac.uk>,
+Jarkko Hietaniemi <jhi@iki.fi>,
+Luther Huffman <lutherh@stratcom.com>,
+Nick Ing-Simmons <nick@ing-simmons.net>,
+Andreas J. KE<ouml>nig <a.koenig@mind.de>,
+Markus Laker <mlaker@contax.co.uk>,
+Andrew M. Langmead <aml@world.std.com>,
+Larry Moore <ljmoore@freespace.net>,
+Paul Moore <Paul.Moore@uk.origin-it.com>,
+Chris Nandor <pudge@pobox.com>,
+Matthias Neeracher <neeracher@mac.com>,
+Philip Newton <pne@cpan.org>,
+Gary Ng <71564.1743@CompuServe.COM>,
+Tom Phoenix <rootbeer@teleport.com>,
+AndrE<eacute> Pirard <A.Pirard@ulg.ac.be>,
+Peter Prymmer <pvhp@forte.com>,
+Hugo van der Sanden <hv@crypt0.demon.co.uk>,
+Gurusamy Sarathy <gsar@activestate.com>,
+Paul J. Schinder <schinder@pobox.com>,
+Michael G Schwern <schwern@pobox.com>,
+Dan Sugalski <dan@sidhe.org>,
+Nathan Torkington <gnat@frii.com>.
+
projects / p5sagit/p5-mst-13.2.git / blobdiff