X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/34aaaa845400abfb74d5e84f98d1d59cdb650982..285a257cbc0a6077bc434af9a84e2ce762d60acd:/pod/perlport.pod
diff --git a/pod/perlport.pod b/pod/perlport.pod
index 457584c..f78e019 100644
--- a/pod/perlport.pod
+++ b/pod/perlport.pod
@@ -75,7 +75,7 @@ This information should not be considered complete; it includes possibly
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
-().
+(C<< >>).
=head1 ISSUES
@@ -104,7 +104,7 @@ newlines:
#...
}
-You can get away with this on Unix and MacOS (they have a single
+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
@@ -171,8 +171,8 @@ newline representation. A single line of code will often suffice:
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 |
---------------------------
@@ -188,7 +188,23 @@ The Unix column assumes that you are not accessing a serial line
"\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
@@ -229,8 +245,11 @@ transferring or storing raw binary numbers.
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
@@ -259,6 +278,9 @@ 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).
+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.
@@ -267,6 +289,13 @@ S perl can emulate Unix filenames with C as path
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
@@ -311,30 +340,61 @@ the user to override the default location of the file.
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 and F, 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 and F, 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<< > >> 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.
+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 instead of C. C is magic and can
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 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
@@ -344,14 +404,35 @@ interaction. A program requiring a command line interface might
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 files when you are done with them. Don't
-C or C an open file. Don't C or C a
-file already tied or opened; C or C 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 files when you
+are done with them. Don't C or C an open file. Don't
+C or C a file already tied or opened; C or C
+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 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. Don't try to clear %ENV by saying C<%ENV = ();>, or,
@@ -367,7 +448,80 @@ C instead.
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 or C 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)
@@ -404,6 +558,14 @@ simple, platform-independent mailing.
The Unix System V IPC (C) is not available
even on all Unix platforms.
+Do not use either the bare result of C or
+bare v-strings (such as C) to represent IPv4 addresses:
+both forms just pack the four bytes into network order. That this
+would be equal to the C language C 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,
+C, and C.
+
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).
@@ -445,16 +607,24 @@ work with any DBM module. See L for more details.
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, 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, 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.
@@ -466,17 +636,25 @@ The value for C<$offset> in Unix will be C<0>, but in Mac OS will be
some large number. C<$offset> can then be added to a Unix time value
to get what should be the proper value on any system.
+On Windows (at least), you shouldn't pass a negative value to C or
+C.
+
=head2 Character sets and character encoding
-Assume little about character sets. Assume nothing about
-numerical values (C, C) 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 comes
-before `b'.
+Assume very little about character sets.
+
+Assume nothing about numerical values (C, C) 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 comes before `b'.
=head2 Internationalisation
@@ -487,6 +665,25 @@ or at least more convenient and native-friendly for non-English
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 and L 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
+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 pragma. (If you want to write your code in UTF-8,
+you can use either the C pragma, or the C pragma.)
+The C and C pragmata are available since Perl 5.6.0, and
+the C pragma since Perl 5.8.0.
+
=head2 System Resources
If your code is destined for systems with severely constrained (or
@@ -511,13 +708,31 @@ more efficient that the first.
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<$)>) to work
+for switching identities (or memberships).
+
+Don't assume set-uid and set-gid semantics. (And even if you do,
+think twice: set-uid and set-gid are a known can of security worms.)
+
=head2 Style
For those times when it is necessary to have platform-specific code,
@@ -530,12 +745,14 @@ Be careful in the tests you supply with your module or programs.
Module code may be fully portable, but its tests might not be. This
often happens when tests spawn off other processes or call external
programs to aid in the testing, or when (as noted above) the tests
-assume certain things about the filesystem and paths. Be careful
-not to depend on a specific output style for errors, such as when
-checking C<$!> 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
@@ -586,6 +803,7 @@ are a few of the more popular Unix flavors:
--------------------------------------------
AIX aix aix
BSD/OS bsdos i386-bsdos
+ Darwin darwin darwin
dgux dgux AViiON-dgux
DYNIX/ptx dynixptx i386-dynixptx
FreeBSD freebsd freebsd-i386
@@ -595,7 +813,7 @@ are a few of the more popular Unix flavors:
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
@@ -663,17 +881,22 @@ often assume nothing about their data.
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
- Cygwin cygwin
+ OS $^O $Config{archname} ID Version
+ --------------------------------------------------------
+ MS-DOS dos ?
+ PC-DOS dos ?
+ OS/2 os2 ?
+ Windows 3.1 ? ? 0 3 01
+ Windows 95 MSWin32 MSWin32-x86 1 4 00
+ Windows 98 MSWin32 MSWin32-x86 1 4 10
+ Windows ME MSWin32 MSWin32-x86 1 ?
+ Windows NT MSWin32 MSWin32-x86 2 4 xx
+ Windows NT MSWin32 MSWin32-ALPHA 2 4 xx
+ Windows NT MSWin32 MSWin32-ppc 2 4 xx
+ Windows 2000 MSWin32 MSWin32-x86 2 5 xx
+ Windows XP MSWin32 MSWin32-x86 2 ?
+ Windows CE MSWin32 ? 3
+ Cygwin cygwin ?
The various MSWin32 Perl's can distinguish the OS they are running on
via the value of the fifth element of the list returned from
@@ -684,6 +907,13 @@ Win32::GetOSVersion(). For example:
print +('3.1','95','NT')[$os_version_info[4]],"\n";
}
+There are also Win32::IsWinNT() and Win32::IsWin95(), try C,
+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
@@ -697,7 +927,7 @@ and L.
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.
+ftp://hobbes.nmsu.edu/pub/os2/dev/emx/ Also L.
=item *
@@ -720,10 +950,11 @@ as L), http://www.cygwin.com/
=item *
The U/WIN environment for Win32,
-
+=item *
+Build instructions for OS/2, L
=back
@@ -783,14 +1014,10 @@ the application or MPW tool version is running, check:
$is_ppc = $MacPerl::Architecture eq 'MacPPC';
$is_68k = $MacPerl::Architecture eq 'Mac68K';
-S and S, 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 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, 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 and its Open Source
+version, Darwin, both run Unix perl natively.
Also see:
@@ -798,15 +1025,15 @@ Also see:
=item *
-The MacPerl Pages, http://www.macperl.com/ .
+MacPerl Development, http://dev.macperl.org/ .
=item *
-The MacPerl mailing lists, http://www.macperl.org/ .
+The MacPerl Pages, http://www.macperl.com/ .
=item *
-MacPerl Module Porters, http://pudge.net/mmp/ .
+The MacPerl mailing lists, http://lists.perl.org/ .
=back
@@ -873,10 +1100,11 @@ process on VMS, is a pure Perl module that can easily be installed on
non-VMS platforms and can be helpful for conversions to and from RMS
native formats.
-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.
@@ -926,12 +1154,12 @@ Perl on VOS is discussed in F in the perl distribution
(installed as L). 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
@@ -940,12 +1168,6 @@ contain a slash character cannot be processed. Such files must be
renamed before they can be processed by Perl. Note that VOS limits
file names to 32 or fewer characters.
-See F for restrictions that apply when Perl is built
-with the alpha version of VOS POSIX.1 support.
-
-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 @INC array like so:
@@ -957,26 +1179,13 @@ can examine the content of the @INC array like so:
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 8xxx!\n";
-
- } elsif (grep(/8000/, @INC)) {
- print "This box is a Stratus HP 8xxx!\n";
-
- } else {
- print "This box is a Stratus 68K!\n";
- }
-
Also see:
=over 4
=item *
-F
+F (installed as L)
=item *
@@ -984,12 +1193,12 @@ 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 http://ftp.stratus.com/pub/vos/vos.html
+VOS Perl on the web at http://ftp.stratus.com/pub/vos/posix/posix.html
=back
@@ -1002,7 +1211,9 @@ 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 for details.
+See L 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.
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.
@@ -1212,6 +1423,7 @@ in the "OTHER" category include:
OS $^O $Config{'archname'}
------------------------------------------
Amiga DOS amigaos m68k-amigos
+ BeOS beos
MPE/iX mpeix PA-RISC1.1
See also:
@@ -1244,7 +1456,7 @@ as well as from CPAN.
=item *
-Plan 9, F
+S, F
=back
@@ -1313,12 +1525,6 @@ suffixes. C<-S> is meaningless. (Win32)
C<-x> (or C<-X>) determine if a file has an executable file type.
(S)
-=item alarm SECONDS
-
-=item alarm
-
-Not implemented. (Win32)
-
=item binmode FILEHANDLE
Meaningless. (S, S)
@@ -1342,32 +1548,35 @@ Only good for changing "owner" and "other" read-write access. (S)
Access permissions are mapped onto VOS access-control list changes. (VOS)
+The actual permissions set depend on the value of the C
+in the SYSTEM environment settings. (Cygwin)
+
=item chown LIST
-Not implemented. (S, Win32, Plan9, S, VOS)
+Not implemented. (S, Win32, S, S)
Does nothing, but won't fail. (Win32)
+A little funky, because VOS's notion of ownership is a little funky (VOS).
+
=item chroot FILENAME
=item chroot
-Not implemented. (S, Win32, VMS, Plan9, S, VOS, VM/ESA)
+Not implemented. (S, Win32, VMS, S, S, VOS, VM/ESA)
=item crypt PLAINTEXT,SALT
May not be available if library or source was not provided when building
perl. (Win32)
-Not implemented. (VOS)
-
=item dbmclose HASH
-Not implemented. (VMS, Plan9, VOS)
+Not implemented. (VMS, S, VOS)
=item dbmopen HASH,DBNAME,MODE
-Not implemented. (VMS, Plan9, VOS)
+Not implemented. (VMS, S, VOS)
=item dump LABEL
@@ -1386,6 +1595,17 @@ Implemented via Spawn. (VM/ESA)
Does not automatically flush output handles on some platforms.
(SunOS, Solaris, HP-UX)
+=item exit EXPR
+
+=item exit
+
+Emulates UNIX exit() (which considers C to indicate an error) by
+mapping the C<1> to SS$_ABORT (C<44>). This behavior may be overridden
+with the pragma C
).
+(C<<