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>).
+(<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 MacOS (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
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.
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.
=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.
Whitespace in filenames is tolerated on most systems, but not all.
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,
+Don't assume C<< > >> won't be the first character of a filename.
+Always use C<< < >> explicitly to open a file for reading,
unless you want the user to be able to specify a pipe open.
open(FILE, "< $existing_file") or die $!;
If filenames might use strange characters, it is safest to open it
with C<sysopen> instead of C<open>. C<open> is magic and can
-translate characters like C<E<gt>>, C<E<lt>>, and C<|>, which may
+translate characters like C<< > >>, C<< < >>, and C<|>, which may
be the wrong thing to do. (Sometimes, though, it's the right thing.)
=head2 System Interaction
Don't open the same file more than once at a time for writing, as some
operating systems put mandatory locks on such files.
+Don't assume that write/modify permission on a directory gives the
+right to add or delete files/directories in that directory. That is
+filesystem specific: in some filesystems you need write/modify
+permission also (or even just) in the file/directory itself. In some
+filesystems (AFS, DFS) the permission to add/delete directory entries
+is a completely separate permission.
+
+Don't assume that a single C<unlink> completely gets rid of the file:
+some filesystems (most notably the ones in VMS) have versioned
+filesystems, and unlink() removes only the most recent one (it doesn't
+remove all the versions because by default the native tools on those
+platforms remove just the most recent version, too). The portable
+idiom to remove all the versions of a file is
+
+ 1 while unlink "file";
+
+This will terminate if the file is undeleteable for some reason
+(protected, not there, and so on).
+
Don't count on a specific environment variable existing in C<%ENV>.
Don't count on C<%ENV> entries being case-sensitive, or even
-case-preserving.
+case-preserving. Don't try to clear %ENV by saying C<%ENV = ();>, or,
+if you really have to, make it conditional on C<$^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.
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>) or 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).
=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
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";
+ }
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 C<Win32::*> modules in L<Win32>.
+
+=item *
+
+The ActiveState Pages, http://www.activestate.com/
-=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 Cygwin environment for Win32; F<README.cygwin> (installed
+as L<perlcygwin>), http://www.cygwin.com/
-=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 U/WIN environment for Win32,
+http://www.research.att.com/sw/tools/uwin/
-=item The U/WIN environment for Win32,
-C<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 *
+
+MacPerl Development, http://dev.macperl.org/ .
+
+=item *
-=item The MacPerl mailing lists, C<http://www.macperl.org/>.
+The MacPerl Pages, http://www.macperl.com/ .
-=item MacPerl Module Porters, C<http://pudge.net/mmp/>.
+=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 organiztion 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
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.
+renamed before they can be processed by Perl. Note that VOS limits
+file names to 32 or fewer characters.
+
+See F<README.vos> for restrictions that apply when Perl is built
+with the alpha version of VOS POSIX.1 support.
-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.
+Perl on VOS is built without any extensions and does not support
+dynamic loading.
The value of C<$^O> on VOS is "VOS". To determine the architecture that
you are running on without resorting to loading all of C<%Config> you
-can examine the content of the C<@INC> array like so:
+can examine the content of the @INC array like so:
if ($^O =~ /VOS/) {
print "I'm on a Stratus box!\n";
=over 4
-=item L<README.vos>
+=item *
+
+F<README.vos>
+
+=item *
-=item VOS mailing list
+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.
-=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/vos.html
=back
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.
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.
=over 4
-=item Amiga, L<README.amiga>
+=item *
+
+Amiga, F<README.amiga> (installed as L<perlamiga>).
-=item Atari, L<README.mint> and Guido Flohr's web page
-C<http://stud.uni-sb.de/~gufl0000/>
+=item *
-=item Be OS, L<README.beos>
+Atari, F<README.mint> and Guido Flohr's web page
+http://stud.uni-sb.de/~gufl0000/
-=item HP 300 MPE/iX, L<README.mpeix> and Mark Bixby's web page
-C<http://www.cccd.edu/~markb/perlix.html>
+=item *
-=item Novell Netware
+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
+
+=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 *
+
+Plan 9, F<README.plan9>
=back
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)
+
=item binmode FILEHANDLE
Meaningless. (S<Mac OS>, S<RISC OS>)
Implemented via Spawn. (VM/ESA)
+Does not automatically flush output handles on some platforms.
+(SunOS, Solaris, HP-UX)
+
=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>, VOS, VM/ESA)
+
+Emulated using multiple interpreters. See L<perlfork>. (Win32)
+
+Does not automatically flush output handles on some platforms.
+(SunOS, Solaris, HP-UX)
=item getlogin
=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
Not implemented. (Plan9, Win32)
+=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 getsockopt SOCKET,LEVEL,OPTNAME
-Not implemented. (S<Mac OS>, Plan9)
+Not implemented. (Plan9)
=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>)
+
+Not implemented, hence not useful for taint checking. (S<RISC OS>)
-Unlike Unix platforms, C<kill(0, $pid)> will actually terminate
-the process. (Win32)
+C<kill()> doesn't have the semantics of C<raise()>, i.e. it doesn't send
+a signal to the identified process like it does on Unix platforms.
+Instead C<kill($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
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)
Only reliable on sockets. (S<RISC OS>)
+Note that the C<socket 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. (MPE/iX, Win32)
+
=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. (MPE/iX, Win32)
+
=item setsockopt SOCKET,LEVEL,OPTNAME,OPTVAL
-Not implemented. (S<Mac OS>, Plan9)
+Not implemented. (Plan9)
=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>)
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>)
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)
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)
Not implemented. (S<Mac OS>, VOS)
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 v1.48, 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.
=back
+=head1 Supported Platforms
+
+As of early 2001 (the Perl releases 5.6.1 and 5.7.1), the following
+platforms are able to build Perl from the standard source code
+distribution available at http://www.perl.com/CPAN/src/index.html
+
+ AIX
+ AmigaOS
+ Darwin (Mac OS X)
+ DG/UX
+ DOS DJGPP 1)
+ DYNIX/ptx
+ EPOC
+ FreeBSD
+ HP-UX
+ IRIX
+ Linux
+ MachTen
+ MacOS Classic 2)
+ NonStop-UX
+ ReliantUNIX (SINIX)
+ OpenBSD
+ OpenVMS (VMS)
+ OS/2
+ OS X
+ QNX
+ Solaris
+ Tru64 UNIX (DEC OSF/1, Digital UNIX)
+ UNICOS
+ UNICOS/mk
+ VOS
+ Win32/NT/2K 3)
+
+ 1) in DOS mode either the DOS or OS/2 ports can be used
+ 2) Mac OS Classic (pre-X) is almost 5.6.1-ready; building from
+ the source does work with 5.6.1, but additional MacOS specific
+ source code is needed for a complete build. See the web
+ site http://dev.macperl.org/ for more information.
+ 3) compilers: Borland, Cygwin, Mingw32 EGCS/GCC, VC++
+
+The following platforms worked for the previous releases (5.6.0 and 5.7.0),
+but we did not manage to test these in time for the 5.7.1 release.
+There is a very good chance that these will work fine with the 5.7.1.
+
+ DomainOS
+ Hurd
+ LynxOS
+ MinGW
+ MPE/iX
+ NetBSD
+ PowerMAX
+ SCO SV
+ SunOS
+ SVR4
+ Unixware
+ Windows 3.1
+ Windows 95
+ Windows 98
+ Windows Me
+
+The following platform worked for the 5.005_03 major release but not
+for 5.6.0. Standardization on UTF-8 as the internal string
+representation in 5.6.0 and 5.6.1 introduced incompatibilities in this
+EBCDIC platform. While Perl 5.7.1 will build on this platform some
+regression tests may fail and the C<use utf8;> pragma typically
+introduces text handling errors.
+
+ OS/390 1)
+
+ 1) previously known as MVS, about to become z/OS.
+
+Strongly related to the OS/390 platform by also being EBCDIC-based
+mainframe platforms are the following platforms:
+
+ POSIX-BC (BS2000)
+ VM/ESA
+
+These are also expected to work, albeit with no UTF-8 support, under 5.6.1
+for the same reasons as OS/390. Contact the mailing list perl-mvs@perl.org
+for more details.
+
+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
+ BeOS
+ BSD/OS
+ 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
+ PowerUX
+ RISC/os
+ SCO ODT/OSR
+ Stellar
+ SVR2
+ TI1500
+ TitanOS
+ Ultrix
+ Unisys Dynix
+ Unixware
+ UTS
+
+Support for the following platform is planned for a future Perl release:
+
+ Netware
+
+The following platforms have their own source code distributions and
+binaries available via http://www.perl.com/CPAN/ports/index.html:
+
+ Perl release
+
+ Netware 5.003_07
+ OS/400 5.005_02
+ Tandem Guardian 5.004
+
+The following platforms have only binaries available via
+http://www.perl.com/CPAN/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.perl.com/CPAN/ports/index.html for binary distributions.
+
+=head1 SEE ALSO
+
+L<perlaix>, L<perlapollo>, L<perlamiga>, L<perlbeos>, L<perlbs200>,
+L<perlce>, L<perlcygwin>, L<perldgux>, L<perldos>, L<perlepoc>, L<perlebcdic>,
+L<perlhurd>, L<perlhpux>, L<perlmachten>, L<perlmacos>, L<perlmint>,
+L<perlmpeix>, L<perlnetware>, L<perlos2>, L<perlos390>, 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>,
-AndrE<eacute> Pirard E<lt>A.Pirard@ulg.ac.beE<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>.
+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 <neeri@iis.ee.ethz.ch>,
+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>.
=head1 VERSION
-Version 1.45, last modified 20 December 1999
+Version 1.50, last modified 10 Jul 2001
https://perl5.git.perl.org / perl5.git / blobdiff