binary, or consider using modules like C<Data::Dumper> (included in
the standard distribution as of Perl 5.005) and C<Storable>.
-=head2 Files
+=head2 Files and Filesystems
Most platforms these days structure files in a hierarchical fashion.
So, it is reasonably safe to assume that any platform supports the
how that path is actually written, differs.
While they are similar, file path specifications differ between Unix,
-Windows, S<Mac OS>, OS/2, VMS, S<RISC OS> and probably others. Unix,
-for example, is one of the few OSes that has the idea of a single root
-directory.
+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 idea of a single
+root directory.
VMS, Windows, and OS/2 can work similarly to Unix with C</> as path
separator, or in their own idiosyncratic ways (such as having several
S<Mac OS> uses 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()>).
+
+The filesystem may support neither access timestamp nor change
+timestamp (meaning that about the only portable timestamp is the
+modification timestamp), or one second granularity of any timestamps
+(e.g. the FAT filesystem limits the time granularity to two seconds).
+
+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.
+
C<RISC OS> perl can emulate Unix filenames with C</> as path
separator, or go native and use C<.> for path separator and C<:> to
signal filing systems and disc names.
splits a pathname into pieces (base filename, full path to directory,
and file suffix).
-Even when on a single platform (if you can call UNIX a single
-platform), remember not to count on the existence or the contents of
-system-specific files, like F</etc/passwd>, F</etc/sendmail.conf>, or
-F</etc/resolv.conf>. For example the F</etc/passwd> may exist but it
-may not contain the encrypted passwords because the system is using
-some form of enhanced security-- or it may not contain all the
-accounts because the system is using NIS. If code does need to rely
-on such a file, include a description of the file and its format in
-the code's documentation, and make it easy for the user to override
-the default location of the file.
+Even when on a single platform (if you can call UNIX a single platform),
+remember not to count on the existence or the contents of
+system-specific files or directories, like F</etc/passwd>,
+F</etc/sendmail.conf>, F</etc/resolv.conf>, or even F</tmp/>. For
+example, F</etc/passwd> may exist but it may not contain the encrypted
+passwords because the system is using some form of enhanced security --
+or it may not contain all the accounts because the system is using NIS.
+If code does need to rely on such a file, include a description of the
+file and its format in the code's documentation, and make it easy for
+the user to override the default location of the file.
+
+Don't assume a text file will end with a newline.
Do not have two files of the same name with different case, like
-F<test.pl> and <Test.pl>, as many platforms have case-insensitive
+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.
make it so the resulting files have a unique (case-insensitively)
first 8 characters.
-Don't assume C<E<lt>> won't be the first character of a filename. Always
-use C<E<gt>> explicitly to open a file for reading:
+There certainly can be whitespace in filenames. 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.
open(FILE, "<$existing_file") or die $!;
+Actually, though, if filenames might use strange characters, it is
+safest to open it with C<sysopen> instead of C<open>, which is magic.
+
=head2 System Interaction
Don't count on per-program environment variables, or per-program current
directories.
+Don't count on specific values of C<$!>.
+
=head2 Interprocess Communication (IPC)
The UNIX System V IPC (C<msg*(), sem*(), shm*()>) is not available
even in all UNIX platforms.
+
=head2 External Subroutines (XS)
XS code, in general, can be made to work with any platform; but dependent
Assume very little about character sets. Do not assume anything about
the numerical values (C<ord()>, C<chr()>) of characters. Do not
assume that the alphabetic characters are encoded contiguously (in
-numerical sense). Do no assume anything about the ordering of the
+numerical 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 the 'b', the accented and other
=head2 Internationalisation
-If you may assume POSIX (a rather large assumption, that: in practise
-that means UNIX) you may read more about the POSIX locale system from
+If you may assume POSIX (a rather large assumption, that in practice
+means UNIX), you may read more about the POSIX locale system from
L<perllocale>. The locale system at least attempts to make things a
-little bit more portable or at least more convenient and
+little bit more portable, or at least more convenient and
native-friendly for non-English users. The system affects character
sets and encoding, and date and time formatting, among other things.
FreeBSD freebsd freebsd-i386
Linux linux i386-linux
HP-UX hpux PA-RISC1.1
- IRIX irix irix
+ IRIX irix irix
OSF1 dec_osf alpha-dec_osf
SunOS solaris sun4-solaris
SunOS solaris i86pc-solaris
which is reserved as a path separator.
Instead of C<flock>, see C<FSpSetFLock> and C<FSpRstFLock> in the
-C<Mac::Files> module.
+C<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
$is_ppc = $MacPerl::Architecture eq 'MacPPC';
$is_68k = $MacPerl::Architecture eq 'Mac68K';
-S<Mac OS X>, to be based on NeXT's OpenStep OS, will be able to run
-MacPerl natively (in the Blue Box, and even in the Yellow Box, once some
-changes to the toolbox calls are made), but Unix perl will also run
-natively.
+S<Mac OS X>, to be based on NeXT's OpenStep OS, will (in theory) be able
+to run MacPerl natively, but Unix perl will also run natively under the
+built-in Unix environment.
Also see:
=back
+=head2 VOS
+
+Perl on VOS is discussed in F<README.vos> in the perl distribution.
+Note that 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
+
+or even a mixture of both as in:
+
+ $ perl -ne "print if /perl_setup/i" >system/notices
+
+Note that 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, any 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, execlp, execl, execvp, 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.
+
+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:
+
+ if (grep(/VOS/, @INC)) {
+ 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 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>
+
+=back
+
+
=head2 EBCDIC Platforms
Recent versions of Perl have been ported to platforms such as OS/400 on
-AS/400 minicomputers as well as OS/390 for IBM Mainframes. Such computers
-use EBCDIC character sets internally (usually Character Code Set ID 00819
-for OS/400 and IBM-1047 for OS/390). Note that on the mainframe perl
-currently works under the "Unix system services for OS/390" (formerly
-known as OpenEdition).
+AS/400 minicomputers as well as OS/390 & VM/ESA for IBM Mainframes. Such
+computers use EBCDIC character sets internally (usually Character Code
+Set ID 00819 for OS/400 and IBM-1047 for OS/390 & VM/ESA). Note that on
+the mainframe perl currently works under the "Unix system services
+for OS/390" (formerly known as OpenEdition) and VM/ESA OpenEdition.
-As of R2.5 of USS for OS/390 that Unix sub-system did not support the
-C<#!> shebang trick for script invocation. Hence, on OS/390 perl scripts
-can executed with a header similar to the following simple script:
+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.
+Hence, on OS/390 and VM/ESA perl scripts can be executed with a header
+similar to the following simple script:
: # use perl
eval 'exec /usr/local/bin/perl -S $0 ${1+"$@"}'
C<pack>, C<print>, C<printf>, C<ord>, C<sort>, C<sprintf>, C<unpack>), as
well as bit-fiddling with ASCII constants using operators like C<^>, C<&>
and C<|>, not to mention dealing with socket interfaces to ASCII computers
-(see L<"NEWLINES">).
+(see L<Newlines>).
Fortunately, most web servers for the mainframe will correctly translate
the C<\n> in the following statement to its ASCII equivalent (note that
-C<\r> is the same under both Unix and OS/390):
+C<\r> is the same under both Unix and OS/390 & VM/ESA):
print "Content-type: text/html\r\n\r\n";
The value of C<$^O> on OS/390 is "os390".
+The value of C<$^O> on VM/ESA is "vmesa".
+
Some simple tricks for determining if you are running on an EBCDIC
platform could include any of the following (perhaps all):
expand system variables in filenames if enclosed in angle brackets, so
C<E<lt>System$DirE<gt>.Modules> would look for the file
S<C<$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<E<lt>E<gt>>> and should
be protected when C<open> is used for input.
Because C<.> was in use as a directory separator and filenames could not
Only good for changing "owner" and "other" read-write access. (S<RISC OS>)
+Access permissions are mapped onto VOS access-control list changes. (VOS)
+
=item chown LIST
-Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>, VOS)
Does nothing, but won't fail. (Win32)
=item chroot
-Not implemented. (S<Mac OS>, Win32, VMS, Plan9, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, Plan9, 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)
+Not implemented. (VMS, Plan9, VOS)
=item dbmopen HASH,DBNAME,MODE
-Not implemented. (VMS, Plan9)
+Not implemented. (VMS, Plan9, VOS)
=item dump LABEL
Not implemented. (S<Mac OS>)
+Implemented via Spawn. (VM/ESA)
+
=item fcntl FILEHANDLE,FUNCTION,SCALAR
Not implemented. (Win32, VMS)
=item flock FILEHANDLE,OPERATION
-Not implemented (S<Mac OS>, VMS, S<RISC OS>).
+Not implemented (S<Mac OS>, VMS, S<RISC OS>, VOS).
Available only on Windows NT (not on Windows 95). (Win32)
=item fork
-Not implemented. (S<Mac OS>, Win32, AmigaOS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, AmigaOS, S<RISC OS>, VOS, VM/ESA)
=item getlogin
=item getpgrp PID
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
=item getppid
=item getpriority WHICH,WHO
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS, VM/ESA)
=item getpwnam NAME
=item getpwent
-Not implemented. (S<Mac OS>, Win32)
+Not implemented. (S<Mac OS>, Win32, VM/ESA)
=item getgrent
-Not implemented. (S<Mac OS>, Win32, VMS)
+Not implemented. (S<Mac OS>, Win32, VMS, VM/ESA)
=item gethostent
=item endpwent
-Not implemented. (S<Mac OS>, Win32)
+Not implemented. (S<Mac OS>, Win32, VM/ESA)
=item endgrent
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VM/ESA)
=item endhostent
Not implemented. (S<Mac OS>, Win32, 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)
+
=item lstat FILEHANDLE
=item lstat EXPR
=item msgrcv ID,VAR,SIZE,TYPE,FLAGS
-Not implemented. (S<Mac OS>, Win32, VMS, Plan9, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, Plan9, S<RISC OS>, VOS)
=item open FILEHANDLE,EXPR
Not implemented. (S<Mac OS>)
+Very limited functionality. (MiNT)
+
=item readlink EXPR
=item readlink
=item semop KEY,OPSTRING
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
=item setpgrp PID,PGRP
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
=item setpriority WHICH,WHO,PRIORITY
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
=item setsockopt SOCKET,LEVEL,OPTNAME,OPTVAL
=item shmwrite ID,STRING,POS,SIZE
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS)
=item socketpair SOCKET1,SOCKET2,DOMAIN,TYPE,PROTOCOL
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS, VM/ESA)
=item stat FILEHANDLE
=item syscall LIST
-Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>)
+Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS, VM/ESA)
=item sysopen FILEHANDLE,FILENAME,MODE,PERMS
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)
+OS>, OS/390, VM/ESA)
=item system LIST
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
+("E<lt>" or "E<gt>") on its own behalf. (MiNT)
+
=item times
Only the first entry returned is nonzero. (S<Mac OS>)
Not implemented. (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')>
+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 only set when the file
+is finally close()d. (AmigaOS)
+
=item utime LIST
Only the modification time is updated. (S<Mac OS>, VMS, S<RISC OS>)
=item waitpid PID,FLAGS
-Not implemented. (S<Mac OS>)
+Not implemented. (S<Mac OS>, VOS)
Can only be applied to process handles returned for processes spawned
using C<system(1, ...)>. (Win32)
=over 4
-=item 1.33, 06 August 1998
+=item v1.38, 31 December 1998
+
+More changes from Jarkko.
+
+=item v1.37, 19 December 1998
+
+More minor changes. Merge two separate version 1.35 documents.
+
+=item v1.36, 9 September 1998
+
+Updated for Stratus VOS. Also known as version 1.35.
+
+=item v1.35, 13 August 1998
+
+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 v1.33, 06 August 1998
Integrate more minor changes.
-=item 1.32, 05 August 1998
+=item v1.32, 05 August 1998
Integrate more minor changes.
-=item 1.30, 03 August 1998
+=item v1.30, 03 August 1998
Major update for RISC OS, other minor changes.
-=item 1.23, 10 July 1998
+=item v1.23, 10 July 1998
First public release with perl5.005.
=head1 AUTHORS / CONTRIBUTORS
Abigail E<lt>abigail@fnx.comE<gt>,
-Charles Bailey E<lt>bailey@genetics.upenn.eduE<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>,
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>
+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>,
Paul Moore E<lt>Paul.Moore@uk.origin-it.comE<gt>,
Chris Nandor E<lt>pudge@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.
+This document is maintained by Chris Nandor
+E<lt>pudge@pobox.comE<gt>.
=head1 VERSION
-Version 1.34, last modified 07 August 1998.
-
-
+Version 1.38, last modified 31 December 1998
projects / p5sagit/p5-mst-13.2.git / blobdiff