{
    "mode": "man",
    "parameter": "PERL58DELTA",
    "section": "1",
    "url": "https://www.chedong.com/phpMan.php/man/PERL58DELTA/1/json",
    "generated": "2026-07-05T15:56:59Z",
    "sections": {
        "NAME": {
            "content": "perl58delta - what is new for perl v5.8.0\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "This document describes differences between the 5.6.0 release and the 5.8.0 release.\n\nMany of the bug fixes in 5.8.0 were already seen in the 5.6.1 maintenance release since the\ntwo releases were kept closely coordinated (while 5.8.0 was still called 5.7.something).\n\nChanges that were integrated into the 5.6.1 release are marked \"[561]\".  Many of these\nchanges have been further developed since 5.6.1 was released, those are marked \"[561+]\".\n\nYou can see the list of changes in the 5.6.1 release (both from the 5.00503 release and the\n5.6.0 release) by reading perl561delta.\n",
            "subsections": [
                {
                    "name": "Highlights In 5.8.0",
                    "content": "•   Better Unicode support\n\n•   New IO Implementation\n\n•   New Thread Implementation\n\n•   Better Numeric Accuracy\n\n•   Safe Signals\n\n•   Many New Modules\n\n•   More Extensive Regression Testing\n"
                },
                {
                    "name": "Incompatible Changes",
                    "content": ""
                },
                {
                    "name": "Binary Incompatibility",
                    "content": ""
                },
                {
                    "name": "Perl 5.8 is not binary compatible with earlier releases of Perl.",
                    "content": ""
                },
                {
                    "name": "You have to recompile your XS modules.",
                    "content": "(Pure Perl modules should continue to work.)\n\nThe major reason for the discontinuity is the new IO architecture called PerlIO.  PerlIO is\nthe default configuration because without it many new features of Perl 5.8 cannot be used.\nIn other words: you just have to recompile your modules containing XS code, sorry about that.\n\nIn future releases of Perl, non-PerlIO aware XS modules may become completely unsupported.\nThis shouldn't be too difficult for module authors, however: PerlIO has been designed as a\ndrop-in replacement (at the source code level) for the stdio interface.\n\nDepending on your platform, there are also other reasons why we decided to break binary\ncompatibility, please read on.\n"
                },
                {
                    "name": "64-bit platforms and malloc",
                    "content": "If your pointers are 64 bits wide, the Perl malloc is no longer being used because it does\nnot work well with 8-byte pointers.  Also, usually the system mallocs on such platforms are\nmuch better optimized for such large memory models than the Perl malloc.  Some memory-hungry\nPerl applications like the PDL don't work well with Perl's malloc.  Finally, other\napplications than Perl (such as modperl) tend to prefer the system malloc.  Such platforms\ninclude Alpha and 64-bit HPPA, MIPS, PPC, and Sparc.\n"
                },
                {
                    "name": "AIX Dynaloading",
                    "content": "The AIX dynaloading now uses in AIX releases 4.3 and newer the native dlopen interface of AIX\ninstead of the old emulated interface.  This change will probably break backward\ncompatibility with compiled modules.  The change was made to make Perl more compliant with\nother applications like modperl which are using the AIX native interface.\n"
                },
                {
                    "name": "Attributes for \"my\" variables now handled at run-time",
                    "content": "The \"my EXPR : ATTRS\" syntax now applies variable attributes at run-time.  (Subroutine and\n\"our\" variables still get attributes applied at compile-time.)  See attributes for additional\ndetails.  In particular, however, this allows variable attributes to be useful for \"tie\"\ninterfaces, which was a deficiency of earlier releases.  Note that the new semantics doesn't\nwork with the Attribute::Handlers module (as of version 0.76).\n"
                },
                {
                    "name": "Socket Extension Dynamic in VMS",
                    "content": "The Socket extension is now dynamically loaded instead of being statically built in.  This\nmay or may not be a problem with ancient TCP/IP stacks of VMS: we do not know since we\nweren't able to test Perl in such configurations.\n"
                },
                {
                    "name": "IEEE-format Floating Point Default on OpenVMS Alpha",
                    "content": "Perl now uses IEEE format (TFLOAT) as the default internal floating point format on OpenVMS\nAlpha, potentially breaking binary compatibility with external libraries or existing data.\nGFLOAT is still available as a configuration option.  The default on VAX (DFLOAT) has not\nchanged.\n"
                },
                {
                    "name": "New Unicode Semantics (no more \"use utf8\", almost)",
                    "content": "Previously in Perl 5.6 to use Unicode one would say \"use utf8\" and then the operations (like\nstring concatenation) were Unicode-aware in that lexical scope.\n\nThis was found to be an inconvenient interface, and in Perl 5.8 the Unicode model has\ncompletely changed: now the \"Unicodeness\" is bound to the data itself, and for most of the\ntime \"use utf8\" is not needed at all.  The only remaining use of \"use utf8\" is when the Perl\nscript itself has been written in the UTF-8 encoding of Unicode.  (UTF-8 has not been made\nthe default since there are many Perl scripts out there that are using various national\neight-bit character sets, which would be illegal in UTF-8.)\n\nSee perluniintro for the explanation of the current model, and utf8 for the current use of\nthe utf8 pragma.\n"
                },
                {
                    "name": "New Unicode Properties",
                    "content": "Unicode scripts are now supported. Scripts are similar to (and superior to) Unicode blocks.\nThe difference between scripts and blocks is that scripts are the glyphs used by a language\nor a group of languages, while the blocks are more artificial groupings of (mostly) 256\ncharacters based on the Unicode numbering.\n\nIn general, scripts are more inclusive, but not universally so. For example, while the script\n\"Latin\" includes all the Latin characters and their various diacritic-adorned versions, it\ndoes not include the various punctuation or digits (since they are not solely \"Latin\").\n\nA number of other properties are now supported, including \"\\p{L&}\", \"\\p{Any}\" \"\\p{Assigned}\",\n\"\\p{Unassigned}\", \"\\p{Blank}\" [561] and \"\\p{SpacePerl}\" [561] (along with their \"\\P{...}\"\nversions, of course).  See perlunicode for details, and more additions.\n\nThe \"In\" or \"Is\" prefix to names used with the \"\\p{...}\" and \"\\P{...}\" are now almost always\noptional. The only exception is that a \"In\" prefix is required to signify a Unicode block\nwhen a block name conflicts with a script name. For example, \"\\p{Tibetan}\" refers to the\nscript, while \"\\p{InTibetan}\" refers to the block. When there is no name conflict, you can\nomit the \"In\" from the block name (e.g. \"\\p{BraillePatterns}\"), but to be safe, it's probably\nbest to always use the \"In\").\n"
                },
                {
                    "name": "REF(...) Instead Of SCALAR(...)",
                    "content": "A reference to a reference now stringifies as \"REF(0x81485ec)\" instead of \"SCALAR(0x81485ec)\"\nin order to be more consistent with the return value of ref().\n"
                },
                {
                    "name": "pack/unpack D/F recycled",
                    "content": "The undocumented pack/unpack template letters D/F have been recycled for better use: now they\nstand for long double (if supported by the platform) and NV (Perl internal floating point\ntype).  (They used to be aliases for d/f, but you never knew that.)\n"
                },
                {
                    "name": "glob() now returns filenames in alphabetical order",
                    "content": "The list of filenames from glob() (or <...>) is now by default sorted alphabetically to be\ncsh-compliant (which is what happened before in most Unix platforms).  (bsdglob() does still\nsort platform natively, ASCII or EBCDIC, unless GLOBALPHASORT is specified.) [561]\n"
                },
                {
                    "name": "Deprecations",
                    "content": "•   The semantics of bless(REF, REF) were unclear and until someone proves it to make some\nsense, it is forbidden.\n\n•   The obsolete chat2 library that should never have been allowed to escape the laboratory\nhas been decommissioned.\n\n•   Using chdir(\"\") or chdir(undef) instead of explicit chdir() is doubtful.  A failure\n(think chdir(somefunction()) can lead into unintended chdir() to the home directory,\ntherefore this behaviour is deprecated.\n\n•   The builtin dump() function has probably outlived most of its usefulness.  The core-\ndumping functionality will remain in future available as an explicit call to\n\"CORE::dump()\", but in future releases the behaviour of an unqualified \"dump()\" call may\nchange.\n\n•   The very dusty examples in the eg/ directory have been removed.  Suggestions for new\nshiny examples welcome but the main issue is that the examples need to be documented,\ntested and (most importantly) maintained.\n\n•   The (bogus) escape sequences \\8 and \\9 now give an optional warning (\"Unrecognized escape\npassed through\").  There is no need to \\-escape any \"\\w\" character.\n\n•   The *glob{FILEHANDLE} is deprecated, use *glob{IO} instead.\n\n•   The \"package;\" syntax (\"package\" without an argument) has been deprecated.  Its semantics\nwere never that clear and its implementation even less so.  If you have used that feature\nto disallow all but fully qualified variables, \"use strict;\" instead.\n\n•   The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still recognised but now\ncause fatal errors.  The previous behaviour of ignoring them by default and warning if\nrequested was unacceptable since it, in a way, falsely promised that the features could\nbe used.\n\n•   In future releases, non-PerlIO aware XS modules may become completely unsupported.  Since\nPerlIO is a drop-in replacement for stdio at the source code level, this shouldn't be\nthat drastic a change.\n\n•   Previous versions of perl and some readings of some sections of Camel III implied that\nthe \":raw\" \"discipline\" was the inverse of \":crlf\".  Turning off \"clrfness\" is no longer\nenough to make a stream truly binary. So the PerlIO \":raw\" layer (or \"discipline\", to use\nthe Camel book's older terminology) is now formally defined as being equivalent to\nbinmode(FH) - which is in turn defined as doing whatever is necessary to pass each byte\nas-is without any translation.  In particular binmode(FH) - and hence \":raw\" - will now\nturn off both CRLF and UTF-8 translation and remove other layers (e.g. :encoding()) which\nwould modify byte stream.\n\n•   The current user-visible implementation of pseudo-hashes (the weird use of the first\narray element) is deprecated starting from Perl 5.8.0 and will be removed in Perl 5.10.0,\nand the feature will be implemented differently.  Not only is the current interface\nrather ugly, but the current implementation slows down normal array and hash use quite\nnoticeably. The \"fields\" pragma interface will remain available.  The restricted hashes\ninterface is expected to be the replacement interface (see Hash::Util).  If your existing\nprograms depends on the underlying implementation, consider using Class::PseudoHash from\nCPAN.\n\n•   The syntaxes \"@a->[...]\" and  \"%h->{...}\" have now been deprecated.\n\n•   After years of trying, suidperl is considered to be too complex to ever be considered\ntruly secure.  The suidperl functionality is likely to be removed in a future release.\n\n•   The 5.005 threads model (module \"Thread\") is deprecated and expected to be removed in\nPerl 5.10.  Multithreaded code should be migrated to the new ithreads model (see threads,\nthreads::shared and perlthrtut).\n\n•   The long deprecated uppercase aliases for the string comparison operators (EQ, NE, LT,\nLE, GE, GT) have now been removed.\n\n•   The tr///C and tr///U features have been removed and will not return; the interface was a\nmistake.  Sorry about that.  For similar functionality, see pack('U0', ...) and\npack('C0', ...). [561]\n\n•   Earlier Perls treated \"sub foo (@bar)\" as equivalent to \"sub foo (@)\".  The prototypes\nare now checked better at compile-time for invalid syntax.  An optional warning is\ngenerated (\"Illegal character in prototype...\")  but this may be upgraded to a fatal\nerror in a future release.\n\n•   The \"exec LIST\" and \"system LIST\" operations now produce warnings on tainted data and in\nsome future release they will produce fatal errors.\n\n•   The existing behaviour when localising tied arrays and hashes is wrong, and will be\nchanged in a future release, so do not rely on the existing behaviour. See \"Localising\nTied Arrays and Hashes Is Broken\".\n"
                },
                {
                    "name": "Core Enhancements",
                    "content": ""
                },
                {
                    "name": "Unicode Overhaul",
                    "content": "Unicode in general should be now much more usable than in Perl 5.6.0 (or even in 5.6.1).\nUnicode can be used in hash keys, Unicode in regular expressions should work now, Unicode in\ntr/// should work now, Unicode in I/O should work now.  See perluniintro for introduction and\nperlunicode for details.\n\n•   The Unicode Character Database coming with Perl has been upgraded to Unicode 3.2.0.  For\nmore information, see http://www.unicode.org/ .  [561+] (5.6.1 has UCD 3.0.1.)\n\n•   For developers interested in enhancing Perl's Unicode capabilities: almost all the UCD\nfiles are included with the Perl distribution in the lib/unicore subdirectory.  The most\nnotable omission, for space considerations, is the Unihan database.\n\n•   The properties \\p{Blank} and \\p{SpacePerl} have been added. \"Blank\" is like C isblank(),\nthat is, it contains only \"horizontal whitespace\" (the space character is, the newline\nisn't), and the \"SpacePerl\" is the Unicode equivalent of \"\\s\" (\\p{Space} isn't, since\nthat includes the vertical tabulator character, whereas \"\\s\" doesn't.)\n\nSee \"New Unicode Properties\" earlier in this document for additional information on\nchanges with Unicode properties.\n"
                },
                {
                    "name": "PerlIO is Now The Default",
                    "content": "•   IO is now by default done via PerlIO rather than system's \"stdio\".  PerlIO allows\n\"layers\" to be \"pushed\" onto a file handle to alter the handle's behaviour.  Layers can\nbe specified at open time via 3-arg form of open:\n\nopen($fh,'>:crlf :utf8', $path) || ...\n\nor on already opened handles via extended \"binmode\":\n\nbinmode($fh,':encoding(iso-8859-7)');\n\nThe built-in layers are: unix (low level read/write), stdio (as in previous Perls),\nperlio (re-implementation of stdio buffering in a portable manner), crlf (does CRLF <=>\n\"\\n\" translation as on Win32, but available on any platform).  A mmap layer may be\navailable if platform supports it (mostly Unixes).\n\nLayers to be applied by default may be specified via the 'open' pragma.\n\nSee \"Installation and Configuration Improvements\" for the effects of PerlIO on your\narchitecture name.\n\n•   If your platform supports fork(), you can use the list form of \"open\" for pipes.  For\nexample:\n\nopen KIDPS, \"-|\", \"ps\", \"aux\" or die $!;\n\nforks the ps(1) command (without spawning a shell, as there are more than three arguments\nto open()), and reads its standard output via the \"KIDPS\" filehandle.  See perlipc.\n\n•   File handles can be marked as accepting Perl's internal encoding of Unicode (UTF-8 or\nUTF-EBCDIC depending on platform) by a pseudo layer \":utf8\" :\n\nopen($fh,\">:utf8\",\"Uni.txt\");\n\nNote for EBCDIC users: the pseudo layer \":utf8\" is erroneously named for you since it's\nnot UTF-8 what you will be getting but instead UTF-EBCDIC.  See perlunicode, utf8, and\nhttp://www.unicode.org/unicode/reports/tr16/ for more information.  In future releases\nthis naming may change.  See perluniintro for more information about UTF-8.\n\n•   If your environment variables (LCALL, LCCTYPE, LANG) look like you want to use UTF-8\n(any of the variables match \"/utf-?8/i\"), your STDIN, STDOUT, STDERR handles and the\ndefault open layer (see open) are marked as UTF-8.  (This feature, like other new\nfeatures that combine Unicode and I/O, work only if you are using PerlIO, but that's the\ndefault.)\n\nNote that after this Perl really does assume that everything is UTF-8: for example if\nsome input handle is not, Perl will probably very soon complain about the input data like\nthis \"Malformed UTF-8 ...\" since any old eight-bit data is not legal UTF-8.\n\nNote for code authors: if you want to enable your users to use UTF-8 as their default\nencoding  but in your code still have eight-bit I/O streams (such as images or zip\nfiles), you need to explicitly open() or binmode() with \":bytes\" (see \"open\" in perlfunc\nand \"binmode\" in perlfunc), or you can just use \"binmode(FH)\" (nice for pre-5.8.0\nbackward compatibility).\n\n•   File handles can translate character encodings from/to Perl's internal Unicode form on\nread/write via the \":encoding()\" layer.\n\n•   File handles can be opened to \"in memory\" files held in Perl scalars via:\n\nopen($fh,'>', \\$variable) || ...\n\n•   Anonymous temporary files are available without need to 'use FileHandle' or other module\nvia\n\nopen($fh,\"+>\", undef) || ...\n\nThat is a literal undef, not an undefined value.\n"
                },
                {
                    "name": "ithreads",
                    "content": "The new interpreter threads (\"ithreads\" for short) implementation of multithreading, by\nArthur Bergman, replaces the old \"5.005 threads\" implementation.  In the ithreads model any\ndata sharing between threads must be explicit, as opposed to the model where data sharing was\nimplicit.  See threads and threads::shared, and perlthrtut.\n\nAs a part of the ithreads implementation Perl will also use any necessary and detectable\nreentrant libc interfaces.\n"
                },
                {
                    "name": "Restricted Hashes",
                    "content": "A restricted hash is restricted to a certain set of keys, no keys outside the set can be\nadded.  Also individual keys can be restricted so that the key cannot be deleted and the\nvalue cannot be changed.  No new syntax is involved: the Hash::Util module is the interface.\n"
                },
                {
                    "name": "Safe Signals",
                    "content": "Perl used to be fragile in that signals arriving at inopportune moments could corrupt Perl's\ninternal state.  Now Perl postpones handling of signals until it's safe (between opcodes).\n\nThis change may have surprising side effects because signals no longer interrupt Perl\ninstantly.  Perl will now first finish whatever it was doing, like finishing an internal\noperation (like sort()) or an external operation (like an I/O operation), and only then look\nat any arrived signals (and before starting the next operation).  No more corrupt internal\nstate since the current operation is always finished first, but the signal may take more time\nto get heard.  Note that breaking out from potentially blocking operations should still work,\nthough.\n"
                },
                {
                    "name": "Understanding of Numbers",
                    "content": "In general a lot of fixing has happened in the area of Perl's understanding of numbers, both\ninteger and floating point.  Since in many systems the standard number parsing functions like\n\"strtoul()\" and \"atof()\" seem to have bugs, Perl tries to work around their deficiencies.\nThis results hopefully in more accurate numbers.\n\nPerl now tries internally to use integer values in numeric conversions and basic arithmetics\n(+ - * /) if the arguments are integers, and tries also to keep the results stored internally\nas integers.  This change leads to often slightly faster and always less lossy arithmetics.\n(Previously Perl always preferred floating point numbers in its math.)\n"
                },
                {
                    "name": "Arrays now always interpolate into double-quoted strings [561]",
                    "content": "In double-quoted strings, arrays now interpolate, no matter what.  The behavior in earlier\nversions of perl 5 was that arrays would interpolate into strings if the array had been\nmentioned before the string was compiled, and otherwise Perl would raise a fatal compile-time\nerror.  In versions 5.000 through 5.003, the error was\n\nLiteral @example now requires backslash\n\nIn versions 5.00401 through 5.6.0, the error was\n\nIn string, @example now must be written as \\@example\n\nThe idea here was to get people into the habit of writing \"fred\\@example.com\" when they\nwanted a literal \"@\" sign, just as they have always written \"Give me back my \\$5\" when they\nwanted a literal \"$\" sign.\n\nStarting with 5.6.1, when Perl now sees an \"@\" sign in a double-quoted string, it always\nattempts to interpolate an array, regardless of whether or not the array has been used or\ndeclared already.  The fatal error has been downgraded to an optional warning:\n\nPossible unintended interpolation of @example in string\n\nThis warns you that \"fred@example.com\" is going to turn into \"fred.com\" if you don't\nbackslash the \"@\".  See http://perl.plover.com/at-error.html for more details about the\nhistory here.\n"
                },
                {
                    "name": "Miscellaneous Changes",
                    "content": "•   AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute to AUTOLOAD\nsubroutines and you can assign to the AUTOLOAD return value.\n\n•   The $Config{byteorder} (and corresponding BYTEORDER in config.h) was previously wrong in\nplatforms if sizeof(long) was 4, but sizeof(IV) was 8.  The byteorder was only\nsizeof(long) bytes long (1234 or 4321), but now it is correctly sizeof(IV) bytes long,\n(12345678 or 87654321).  (This problem didn't affect Windows platforms.)\n\nAlso, $Config{byteorder} is now computed dynamically--this is more robust with \"fat\nbinaries\" where an executable image contains binaries for more than one binary platform,\nand when cross-compiling.\n\n•   \"perl -d:Module=arg,arg,arg\" now works (previously one couldn't pass in multiple\narguments.)\n\n•   \"do\" followed by a bareword now ensures that this bareword isn't a keyword (to avoid a\nbug where \"do q(foo.pl)\" tried to call a subroutine called \"q\").  This means that for\nexample instead of \"do format()\" you must write \"do &format()\".\n\n•   The builtin dump() now gives an optional warning \"dump() better written as CORE::dump()\",\nmeaning that by default \"dump(...)\" is resolved as the builtin dump() which dumps core\nand aborts, not as (possibly) user-defined \"sub dump\".  To call the latter, qualify the\ncall as \"&dump(...)\".  (The whole dump() feature is to considered deprecated, and\npossibly removed/changed in future releases.)\n\n•   chomp() and chop() are now overridable.  Note, however, that their prototype (as given by\n\"prototype(\"CORE::chomp\")\" is undefined, because it cannot be expressed and therefore one\ncannot really write replacements to override these builtins.\n\n•   END blocks are now run even if you exit/die in a BEGIN block.  Internally, the execution\nof END blocks is now controlled by PLexitflags & PERLEXITDESTRUCTEND. This enables\nthe new behaviour for Perl embedders. This will default in 5.10. See perlembed.\n\n•   Formats now support zero-padded decimal fields.\n\n•   Although \"you shouldn't do that\", it was possible to write code that depends on Perl's\nhashed key order (Data::Dumper does this).  The new algorithm \"One-at-a-Time\" produces a\ndifferent hashed key order.  More details are in \"Performance Enhancements\".\n\n•   lstat(FILEHANDLE) now gives a warning because the operation makes no sense.  In future\nreleases this may become a fatal error.\n\n•   Spurious syntax errors generated in certain situations, when glob() caused File::Glob to\nbe loaded for the first time, have been fixed. [561]\n\n•   Lvalue subroutines can now return \"undef\" in list context.  However, the lvalue\nsubroutine feature still remains experimental.  [561+]\n\n•   A lost warning \"Can't declare ... dereference in my\" has been restored (Perl had it\nearlier but it became lost in later releases.)\n\n•   A new special regular expression variable has been introduced: $^N, which contains the\nmost-recently closed group (submatch).\n\n•   \"no Module;\" does not produce an error even if Module does not have an unimport() method.\nThis parallels the behavior of \"use\" vis-a-vis \"import\". [561]\n\n•   The numerical comparison operators return \"undef\" if either operand is a NaN.  Previously\nthe behaviour was unspecified.\n\n•   \"our\" can now have an experimental optional attribute \"unique\" that affects how global\nvariables are shared among multiple interpreters, see \"our\" in perlfunc.\n\n•   The following builtin functions are now overridable: each(), keys(), pop(), push(),\nshift(), splice(), unshift(). [561]\n\n•   \"pack() / unpack()\" can now group template letters with \"()\" and then apply\nrepetition/count modifiers on the groups.\n\n•   \"pack() / unpack()\" can now process the Perl internal numeric types: IVs, UVs, NVs-- and\nalso long doubles, if supported by the platform.  The template letters are \"j\", \"J\", \"F\",\nand \"D\".\n\n•   \"pack('U0a*', ...)\" can now be used to force a string to UTF-8.\n\n•   my PACKAGE $obj now works. [561]\n\n•   POSIX::sleep() now returns the number of unslept seconds (as the POSIX standard says), as\nopposed to CORE::sleep() which returns the number of slept seconds.\n\n•   printf() and sprintf() now support parameter reordering using the \"%\\d+\\$\" and \"*\\d+\\$\"\nsyntaxes.  For example\n\nprintf \"%2\\$s %1\\$s\\n\", \"foo\", \"bar\";\n\nwill print \"bar foo\\n\".  This feature helps in writing internationalised software, and in\ngeneral when the order of the parameters can vary.\n\n•   The (\\&) prototype now works properly. [561]\n\n•   prototype(\\[$@%&]) is now available to implicitly create references (useful for example\nif you want to emulate the tie() interface).\n\n•   A new command-line option, \"-t\" is available.  It is the little brother of \"-T\": instead\nof dying on taint violations, lexical warnings are given.  This is only meant as a\ntemporary debugging aid while securing the code of old legacy applications.  This is not\na substitute for -T.\n\n•   In other taint news, the \"exec LIST\" and \"system LIST\" have now been considered too risky\n(think \"exec @ARGV\": it can start any program with any arguments), and now the said forms\ncause a warning under lexical warnings.  You should carefully launder the arguments to\nguarantee their validity.  In future releases of Perl the forms will become fatal errors\nso consider starting laundering now.\n\n•   Tied hash interfaces are now required to have the EXISTS and DELETE methods (either own\nor inherited).\n\n•   If tr/// is just counting characters, it doesn't attempt to modify its target.\n\n•   untie() will now call an UNTIE() hook if it exists.  See perltie for details. [561]\n\n•   \"utime\" in perlfunc now supports \"utime undef, undef, @files\" to change the file\ntimestamps to the current time.\n\n•   The rules for allowing underscores (underbars) in numeric constants have been relaxed and\nsimplified: now you can have an underscore simply between digits.\n\n•   Rather than relying on C's argv[0] (which may not contain a full pathname) where possible\n$^X is now set by asking the operating system.  (eg by reading /proc/self/exe on Linux,\n/proc/curproc/file on FreeBSD)\n\n•   A new variable, \"${^TAINT}\", indicates whether taint mode is enabled.\n\n•   You can now override the readline() builtin, and this overrides also the <FILEHANDLE>\nangle bracket operator.\n\n•   The command-line options -s and -F are now recognized on the shebang (#!) line.\n\n•   Use of the \"/c\" match modifier without an accompanying \"/g\" modifier elicits a new\nwarning: \"Use of /c modifier is meaningless without /g\".\n\nUse of \"/c\" in substitutions, even with \"/g\", elicits \"Use of /c modifier is meaningless\nin s///\".\n\nUse of \"/g\" with \"split\" elicits \"Use of /g modifier is meaningless in split\".\n\n•   Support for the \"CLONE\" special subroutine had been added.  With ithreads, when a new\nthread is created, all Perl data is cloned, however non-Perl data cannot be cloned\nautomatically.  In \"CLONE\" you can do whatever you need to do, like for example handle\nthe cloning of non-Perl data, if necessary.  \"CLONE\" will be executed once for every\npackage that has it defined or inherited.  It will be called in the context of the new\nthread, so all modifications are made in the new area.\n\nSee perlmod\n"
                },
                {
                    "name": "Modules and Pragmata",
                    "content": ""
                },
                {
                    "name": "New Modules and Pragmata",
                    "content": "•   \"Attribute::Handlers\", originally by Damian Conway and now maintained by Arthur Bergman,\nallows a class to define attribute handlers.\n\npackage MyPack;\nuse Attribute::Handlers;\nsub Wolf :ATTR(SCALAR) { print \"howl!\\n\" }\n\n# later, in some package using or inheriting from MyPack...\n\nmy MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called\n\nBoth variables and routines can have attribute handlers.  Handlers can be specific to\ntype (SCALAR, ARRAY, HASH, or CODE), or specific to the exact compilation phase (BEGIN,\nCHECK, INIT, or END).  See Attribute::Handlers.\n\n•   \"B::Concise\", by Stephen McCamant, is a new compiler backend for walking the Perl syntax\ntree, printing concise info about ops.  The output is highly customisable.  See\nB::Concise. [561+]\n\n•   The new bignum, bigint, and bigrat pragmas, by Tels, implement transparent bignum support\n(using the Math::BigInt, Math::BigFloat, and Math::BigRat backends).\n\n•   \"Class::ISA\", by Sean Burke, is a module for reporting the search path for a class's ISA\ntree.  See Class::ISA.\n\n•   \"Cwd\" now has a split personality: if possible, an XS extension is used, (this will\nhopefully be faster, more secure, and more robust) but if not possible, the familiar Perl\nimplementation is used.\n\n•   \"Devel::PPPort\", originally by Kenneth Albanowski and now maintained by Paul Marquess,\nhas been added.  It is primarily used by \"h2xs\" to enhance portability of XS modules\nbetween different versions of Perl.  See Devel::PPPort.\n\n•   \"Digest\", frontend module for calculating digests (checksums), from Gisle Aas, has been\nadded.  See Digest.\n\n•   \"Digest::MD5\" for calculating MD5 digests (checksums) as defined in RFC 1321, from Gisle\nAas, has been added.  See Digest::MD5.\n\nuse Digest::MD5 'md5hex';\n\n$digest = md5hex(\"Thirsty Camel\");\n\nprint $digest, \"\\n\"; # 01d19d9d2045e005c3f1b80e8b164de1\n\nNOTE: the \"MD5\" backward compatibility module is deliberately not included since its\nfurther use is discouraged.\n\nSee also PerlIO::via::QuotedPrint.\n\n•   \"Encode\", originally by Nick Ing-Simmons and now maintained by Dan Kogai, provides a\nmechanism to translate between different character encodings.  Support for Unicode,\nISO-8859-1, and ASCII are compiled in to the module.  Several other encodings (like the\nrest of the ISO-8859, CP*/Win*, Mac, KOI8-R, three variants EBCDIC, Chinese, Japanese,\nand Korean encodings) are included and can be loaded at runtime.  (For space\nconsiderations, the largest Chinese encodings have been separated into their own CPAN\nmodule, Encode::HanExtra, which Encode will use if available).  See Encode.\n\nAny encoding supported by Encode module is also available to the \":encoding()\" layer if\nPerlIO is used.\n\n•   \"Hash::Util\" is the interface to the new restricted hashes feature.  (Implemented by\nJeffrey Friedl, Nick Ing-Simmons, and Michael Schwern.)  See Hash::Util.\n\n•   \"I18N::Langinfo\" can be used to query locale information.  See I18N::Langinfo.\n\n•   \"I18N::LangTags\", by Sean Burke, has functions for dealing with RFC3066-style language\ntags.  See I18N::LangTags.\n\n•   \"ExtUtils::Constant\", by Nicholas Clark, is a new tool for extension writers for\ngenerating XS code to import C header constants.  See ExtUtils::Constant.\n\n•   \"Filter::Simple\", by Damian Conway, is an easy-to-use frontend to Filter::Util::Call.\nSee Filter::Simple.\n\n# in MyFilter.pm:\n\npackage MyFilter;\n\nuse Filter::Simple sub {\nwhile (my ($from, $to) = splice @, 0, 2) {\ns/$from/$to/g;\n}\n};\n\n1;\n\n# in user's code:\n\nuse MyFilter qr/red/ => 'green';\n\nprint \"red\\n\";   # this code is filtered, will print \"green\\n\"\nprint \"bored\\n\"; # this code is filtered, will print \"bogreen\\n\"\n\nno MyFilter;\n\nprint \"red\\n\";   # this code is not filtered, will print \"red\\n\"\n\n•   \"File::Temp\", by Tim Jenness, allows one to create temporary files and directories in an\neasy, portable, and secure way.  See File::Temp.  [561+]\n\n•   \"Filter::Util::Call\", by Paul Marquess, provides you with the framework to write source\nfilters in Perl.  For most uses, the frontend Filter::Simple is to be preferred.  See\nFilter::Util::Call.\n\n•   \"if\", by Ilya Zakharevich, is a new pragma for conditional inclusion of modules.\n\n•   libnet, by Graham Barr, is a collection of perl5 modules related to network programming.\nSee Net::FTP, Net::NNTP, Net::Ping (not part of libnet, but related), Net::POP3,\nNet::SMTP, and Net::Time.\n\nPerl installation leaves libnet unconfigured; use libnetcfg to configure it.\n\n•   \"List::Util\", by Graham Barr, is a selection of general-utility list subroutines, such as\nsum(), min(), first(), and shuffle().  See List::Util.\n\n•   \"Locale::Constants\", \"Locale::Country\", \"Locale::Currency\" \"Locale::Language\", and\nLocale::Script, by Neil Bowers, have been added.  They provide the codes for various\nlocale standards, such as \"fr\" for France, \"usd\" for US Dollar, and \"ja\" for Japanese.\n\nuse Locale::Country;\n\n$country = code2country('jp');               # $country gets 'Japan'\n$code    = country2code('Norway');           # $code gets 'no'\n\nSee Locale::Constants, Locale::Country, Locale::Currency, and Locale::Language.\n\n•   \"Locale::Maketext\", by Sean Burke, is a localization framework.  See Locale::Maketext,\nand Locale::Maketext::TPJ13.  The latter is an article about software localization,\noriginally published in The Perl Journal #13, and republished here with kind permission.\n\n•   \"Math::BigRat\" for big rational numbers, to accompany Math::BigInt and Math::BigFloat,\nfrom Tels.  See Math::BigRat.\n\n•   \"Memoize\" can make your functions faster by trading space for time, from Mark-Jason\nDominus.  See Memoize.\n\n•   \"MIME::Base64\", by Gisle Aas, allows you to encode data in base64, as defined in RFC 2045\n- MIME (Multipurpose Internet Mail Extensions).\n\nuse MIME::Base64;\n\n$encoded = encodebase64('Aladdin:open sesame');\n$decoded = decodebase64($encoded);\n\nprint $encoded, \"\\n\"; # \"QWxhZGRpbjpvcGVuIHNlc2FtZQ==\"\n\nSee MIME::Base64.\n\n•   \"MIME::QuotedPrint\", by Gisle Aas, allows you to encode data in quoted-printable\nencoding, as defined in RFC 2045 - MIME (Multipurpose Internet Mail Extensions).\n\nuse MIME::QuotedPrint;\n\n$encoded = encodeqp(\"\\xDE\\xAD\\xBE\\xEF\");\n$decoded = decodeqp($encoded);\n\nprint $encoded, \"\\n\"; # \"=DE=AD=BE=EF\\n\"\nprint $decoded, \"\\n\"; # \"\\xDE\\xAD\\xBE\\xEF\\n\"\n\nSee also PerlIO::via::QuotedPrint.\n\n•   \"NEXT\", by Damian Conway, is a pseudo-class for method redispatch.  See NEXT.\n\n•   \"open\" is a new pragma for setting the default I/O layers for open().\n\n•   \"PerlIO::scalar\", by Nick Ing-Simmons, provides the implementation of IO to \"in memory\"\nPerl scalars as discussed above.  It also serves as an example of a loadable PerlIO\nlayer.  Other future possibilities include PerlIO::Array and PerlIO::Code.  See\nPerlIO::scalar.\n\n•   \"PerlIO::via\", by Nick Ing-Simmons, acts as a PerlIO layer and wraps PerlIO layer\nfunctionality provided by a class (typically implemented in Perl code).\n\n•   \"PerlIO::via::QuotedPrint\", by Elizabeth Mattijsen, is an example of a \"PerlIO::via\"\nclass:\n\nuse PerlIO::via::QuotedPrint;\nopen($fh,\">:via(QuotedPrint)\",$path);\n\nThis will automatically convert everything output to $fh to Quoted-Printable.  See\nPerlIO::via and PerlIO::via::QuotedPrint.\n\n•   \"Pod::ParseLink\", by Russ Allbery, has been added, to parse L<> links in pods as\ndescribed in the new perlpodspec.\n\n•   \"Pod::Text::Overstrike\", by Joe Smith, has been added.  It converts POD data to formatted\noverstrike text.  See Pod::Text::Overstrike. [561+]\n\n•   \"Scalar::Util\" is a selection of general-utility scalar subroutines, such as blessed(),\nreftype(), and tainted().  See Scalar::Util.\n\n•   \"sort\" is a new pragma for controlling the behaviour of sort().\n\n•   \"Storable\" gives persistence to Perl data structures by allowing the storage and\nretrieval of Perl data to and from files in a fast and compact binary format.  Because in\neffect Storable does serialisation of Perl data structures, with it you can also clone\ndeep, hierarchical datastructures.  Storable was originally created by Raphael Manfredi,\nbut it is now maintained by Abhijit Menon-Sen.  Storable has been enhanced to understand\nthe two new hash features, Unicode keys and restricted hashes.  See Storable.\n\n•   \"Switch\", by Damian Conway, has been added.  Just by saying\n\nuse Switch;\n\nyou have \"switch\" and \"case\" available in Perl.\n\nuse Switch;\n\nswitch ($val) {\n\ncase 1          { print \"number 1\" }\ncase \"a\"        { print \"string a\" }\ncase [1..10,42] { print \"number in list\" }\ncase (@array)   { print \"number in list\" }\ncase /\\w+/      { print \"pattern\" }\ncase qr/\\w+/    { print \"pattern\" }\ncase (%hash)    { print \"entry in hash\" }\ncase (\\%hash)   { print \"entry in hash\" }\ncase (\\&sub)    { print \"arg to subroutine\" }\nelse            { print \"previous case not true\" }\n}\n\nSee Switch.\n\n•   \"Test::More\", by Michael Schwern, is yet another framework for writing test scripts, more\nextensive than Test::Simple.  See Test::More.\n\n•   \"Test::Simple\", by Michael Schwern, has basic utilities for writing tests.   See\nTest::Simple.\n\n•   \"Text::Balanced\", by Damian Conway, has been added, for extracting delimited text\nsequences from strings.\n\nuse Text::Balanced 'extractdelimited';\n\n($a, $b) = extractdelimited(\"'never say never', he never said\", \"'\", '');\n\n$a will be \"'never say never'\", $b will be ', he never said'.\n\nIn addition to extractdelimited(), there are also extractbracketed(),\nextractquotelike(), extractcodeblock(), extractvariable(), extracttagged(),\nextractmultiple(), gendelimitedpat(), and genextracttagged().  With these, you can\nimplement rather advanced parsing algorithms.  See Text::Balanced.\n\n•   \"threads\", by Arthur Bergman, is an interface to interpreter threads.  Interpreter\nthreads (ithreads) is the new thread model introduced in Perl 5.6 but only available as\nan internal interface for extension writers (and for Win32 Perl for \"fork()\" emulation).\nSee threads, threads::shared, and perlthrtut.\n\n•   \"threads::shared\", by Arthur Bergman, allows data sharing for interpreter threads.  See\nthreads::shared.\n\n•   \"Tie::File\", by Mark-Jason Dominus, associates a Perl array with the lines of a file.\nSee Tie::File.\n\n•   \"Tie::Memoize\", by Ilya Zakharevich, provides on-demand loaded hashes.  See Tie::Memoize.\n\n•   \"Tie::RefHash::Nestable\", by Edward Avis, allows storing hash references (unlike the\nstandard Tie::RefHash)  The module is contained within Tie::RefHash.  See Tie::RefHash.\n\n•   \"Time::HiRes\", by Douglas E. Wegscheid, provides high resolution timing (ualarm, usleep,\nand gettimeofday).  See Time::HiRes.\n\n•   \"Unicode::UCD\" offers a querying interface to the Unicode Character Database.  See\nUnicode::UCD.\n\n•   \"Unicode::Collate\", by SADAHIRO Tomoyuki, implements the UCA (Unicode Collation\nAlgorithm) for sorting Unicode strings.  See Unicode::Collate.\n\n•   \"Unicode::Normalize\", by SADAHIRO Tomoyuki, implements the various Unicode normalization\nforms.  See Unicode::Normalize.\n\n•   \"XS::APItest\", by Tim Jenness, is a test extension that exercises XS APIs.  Currently\nonly \"printf()\" is tested: how to output various basic data types from XS.\n\n•   \"XS::Typemap\", by Tim Jenness, is a test extension that exercises XS typemaps.  Nothing\ngets installed, but the code is worth studying for extension writers.\n"
                },
                {
                    "name": "Updated And Improved Modules and Pragmata",
                    "content": "•   The following independently supported modules have been updated to the newest versions\nfrom CPAN: CGI, CPAN, DBFile, File::Spec, File::Temp, Getopt::Long, Math::BigFloat,\nMath::BigInt, the podlators bundle (Pod::Man, Pod::Text), Pod::LaTeX [561+], Pod::Parser,\nStorable, Term::ANSIColor, Test, Text-Tabs+Wrap.\n\n•   attributes::reftype() now works on tied arguments.\n\n•   AutoLoader can now be disabled with \"no AutoLoader;\".\n\n•   B::Deparse has been significantly enhanced by Robin Houston.  It can now deparse almost\nall of the standard test suite (so that the tests still succeed).  There is a make target\n\"test.deparse\" for trying this out.\n\n•   Carp now has better interface documentation, and the @CARPNOT interface has been added\nto get optional control over where errors are reported independently of @ISA, by Ben\nTilly.\n\n•   Class::Struct can now define the classes in compile time.\n\n•   Class::Struct now assigns the array/hash element if the accessor is called with an\narray/hash element as the sole argument.\n\n•   The return value of Cwd::fastcwd() is now tainted.\n\n•   Data::Dumper now has an option to sort hashes.\n\n•   Data::Dumper now has an option to dump code references using B::Deparse.\n\n•   DBFile now supports newer Berkeley DB versions, among other improvements.\n\n•   Devel::Peek now has an interface for the Perl memory statistics (this works only if you\nare using perl's malloc, and if you have compiled with debugging).\n\n•   The English module can now be used without the infamous performance hit by saying\n\nuse English '-nomatchvars';\n\n(Assuming, of course, that you don't need the troublesome variables \"$`\", $&, or \"$'\".)\nAlso, introduced @LASTMATCHSTART and @LASTMATCHEND English aliases for \"@-\" and \"@+\".\n\n•   ExtUtils::MakeMaker has been significantly cleaned up and fixed.  The enhanced version\nhas also been backported to earlier releases of Perl and submitted to CPAN so that the\nearlier releases can enjoy the fixes.\n\n•   The arguments of WriteMakefile() in Makefile.PL are now checked for sanity much more\ncarefully than before.  This may cause new warnings when modules are being installed.\nSee ExtUtils::MakeMaker for more details.\n\n•   ExtUtils::MakeMaker now uses File::Spec internally, which hopefully leads to better\nportability.\n\n•   Fcntl, Socket, and Sys::Syslog have been rewritten by Nicholas Clark to use the new-style\nconstant dispatch section (see ExtUtils::Constant).  This means that they will be more\nrobust and hopefully faster.\n\n•   File::Find now chdir()s correctly when chasing symbolic links. [561]\n\n•   File::Find now has pre- and post-processing callbacks.  It also correctly changes\ndirectories when chasing symbolic links.  Callbacks (naughtily) exiting with \"next;\"\ninstead of \"return;\" now work.\n\n•   File::Find is now (again) reentrant.  It also has been made more portable.\n\n•   The warnings issued by File::Find now belong to their own category.  You can\nenable/disable them with \"use/no warnings 'File::Find';\".\n\n•   File::Glob::glob() has been renamed to File::Glob::bsdglob() because the name clashes\nwith the builtin glob().  The older name is still available for compatibility, but is\ndeprecated. [561]\n\n•   File::Glob now supports \"GLOBLIMIT\" constant to limit the size of the returned list of\nfilenames.\n\n•   IPC::Open3 now allows the use of numeric file descriptors.\n\n•   IO::Socket now has an atmark() method, which returns true if the socket is positioned at\nthe out-of-band mark.  The method is also exportable as a sockatmark() function.\n\n•   IO::Socket::INET failed to open the specified port if the service name was not known.  It\nnow correctly uses the supplied port number as is. [561]\n\n•   IO::Socket::INET has support for the ReusePort option (if your platform supports it).\nThe Reuse option now has an alias, ReuseAddr.  For clarity, you may want to prefer\nReuseAddr.\n\n•   IO::Socket::INET now supports a value of zero for \"LocalPort\" (usually meaning that the\noperating system will make one up.)\n\n•   'use lib' now works identically to @INC.  Removing directories with 'no lib' now works.\n\n•   Math::BigFloat and Math::BigInt have undergone a full rewrite by Tels.  They are now\nmagnitudes faster, and they support various bignum libraries such as GMP and PARI as\ntheir backends.\n\n•   Math::Complex handles inf, NaN etc., better.\n\n•   Net::Ping has been considerably enhanced by Rob Brown: multihoming is now supported,\nWin32 functionality is better, there is now time measuring functionality (optionally\nhigh-resolution using Time::HiRes), and there is now \"external\" protocol which uses\nNet::Ping::External module which runs your external ping utility and parses the output.\nA version of Net::Ping::External is available in CPAN.\n\nNote that some of the Net::Ping tests are disabled when running under the Perl\ndistribution since one cannot assume one or more of the following: enabled echo port at\nlocalhost, full Internet connectivity, or sympathetic firewalls.  You can set the\nenvironment variable PERLTESTNetPing to \"1\" (one) before running the Perl test suite\nto enable all the Net::Ping tests.\n\n•   POSIX::sigaction() is now much more flexible and robust.  You can now install coderef\nhandlers, 'DEFAULT', and 'IGNORE' handlers, installing new handlers was not atomic.\n\n•   In Safe, %INC is now localised in a Safe compartment so that use/require work.\n\n•   In SDBMFile on DOSish platforms, some keys went missing because of lack of support for\nfiles with \"holes\".  A workaround for the problem has been added.\n\n•   In Search::Dict one can now have a pre-processing hook for the lines being searched.\n\n•   The Shell module now has an OO interface.\n\n•   In Sys::Syslog there is now a failover mechanism that will go through alternative\nconnection mechanisms until the message is successfully logged.\n\n•   The Test module has been significantly enhanced.\n\n•   Time::Local::timelocal() does not handle fractional seconds anymore.  The rationale is\nthat neither does localtime(), and timelocal() and localtime() are supposed to be\ninverses of each other.\n\n•   The vars pragma now supports declaring fully qualified variables.  (Something that\n\"our()\" does not and will not support.)\n\n•   The \"utf8::\" name space (as in the pragma) provides various Perl-callable functions to\nprovide low level access to Perl's internal Unicode representation.  At the moment only\nlength() has been implemented.\n"
                },
                {
                    "name": "Utility Changes",
                    "content": "•   Emacs perl mode (emacs/cperl-mode.el) has been updated to version 4.31.\n\n•   emacs/e2ctags.pl is now much faster.\n\n•   \"enc2xs\" is a tool for people adding their own encodings to the Encode module.\n\n•   \"h2ph\" now supports C trigraphs.\n\n•   \"h2xs\" now produces a template README.\n\n•   \"h2xs\" now uses \"Devel::PPPort\" for better portability between different versions of\nPerl.\n\n•   \"h2xs\" uses the new ExtUtils::Constant module which will affect newly created extensions\nthat define constants.  Since the new code is more correct (if you have two constants\nwhere the first one is a prefix of the second one, the first constant never got defined),\nless lossy (it uses integers for integer constant, as opposed to the old code that used\nfloating point numbers even for integer constants), and slightly faster, you might want\nto consider regenerating your extension code (the new scheme makes regenerating easy).\nh2xs now also supports C trigraphs.\n\n•   \"libnetcfg\" has been added to configure libnet.\n\n•   \"perlbug\" is now much more robust.  It also sends the bug report to perl.org, not\nperl.com.\n\n•   \"perlcc\" has been rewritten and its user interface (that is, command line) is much more\nlike that of the Unix C compiler, cc.  (The perlbc tools has been removed.  Use \"perlcc\n-B\" instead.)  Note that perlcc is still considered very experimental and unsupported.\n[561]\n\n•   \"perlivp\" is a new Installation Verification Procedure utility for running any time after\ninstalling Perl.\n\n•   \"piconv\" is an implementation of the character conversion utility \"iconv\", demonstrating\nthe new Encode module.\n\n•   \"pod2html\" now allows specifying a cache directory.\n\n•   \"pod2html\" now produces XHTML 1.0.\n\n•   \"pod2html\" now understands POD written using different line endings (PC-like CRLF versus\nUnix-like LF versus MacClassic-like CR).\n\n•   \"s2p\" has been completely rewritten in Perl.  (It is in fact a full implementation of sed\nin Perl: you can use the sed functionality by using the \"psed\" utility.)\n\n•   \"xsubpp\" now understands POD documentation embedded in the *.xs files. [561]\n\n•   \"xsubpp\" now supports the OUT keyword.\n"
                },
                {
                    "name": "New Documentation",
                    "content": "•   perl56delta details the changes between the 5.005 release and the 5.6.0 release.\n\n•   perlclib documents the internal replacements for standard C library functions.\n(Interesting only for extension writers and Perl core hackers.) [561+]\n\n•   perldebtut is a Perl debugging tutorial. [561+]\n\n•   perlebcdic contains considerations for running Perl on EBCDIC platforms. [561+]\n\n•   perlintro is a gentle introduction to Perl.\n\n•   perliol documents the internals of PerlIO with layers.\n\n•   perlmodstyle is a style guide for writing modules.\n\n•   perlnewmod tells about writing and submitting a new module. [561+]\n\n•   perlpacktut is a pack() tutorial.\n\n•   perlpod has been rewritten to be clearer and to record the best practices gathered over\nthe years.\n\n•   perlpodspec is a more formal specification of the pod format, mainly of interest for\nwriters of pod applications, not to people writing in pod.\n\n•   perlretut is a regular expression tutorial. [561+]\n\n•   perlrequick is a regular expressions quick-start guide.  Yes, much quicker than\nperlretut. [561]\n\n•   perltodo has been updated.\n\n•   perltootc has been renamed as perltooc (to not to conflict with perltoot in filesystems\nrestricted to \"8.3\" names).\n\n•   perluniintro is an introduction to using Unicode in Perl.  (perlunicode is more of a\ndetailed reference and background information)\n\n•   perlutil explains the command line utilities packaged with the Perl distribution. [561+]\n\nThe following platform-specific documents are available before the installation as\nREADME.platform, and after the installation as perlplatform:\n\nperlaix perlamiga perlapollo perlbeos perlbs2000\nperlce perlcygwin perldgux perldos perlepoc perlfreebsd perlhpux\nperlhurd perlirix perlmachten perlmacos perlmint perlmpeix\nperlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris\nperltru64 perluts perlvmesa perlvms perlvos perlwin32\n\nThese documents usually detail one or more of the following subjects: configuring, building,\ntesting, installing, and sometimes also using Perl on the said platform.\n\nEastern Asian Perl users are now welcomed in their own languages: README.jp (Japanese),\nREADME.ko (Korean), README.cn (simplified Chinese) and README.tw (traditional Chinese), which\nare written in normal pod but encoded in EUC-JP, EUC-KR, EUC-CN and Big5.  These will get\ninstalled as\n\nperljp perlko perlcn perltw\n\n•   The documentation for the POSIX-BC platform is called \"BS2000\", to avoid confusion with\nthe Perl POSIX module.\n\n•   The documentation for the WinCE platform is called perlce (README.ce in the source code\nkit), to avoid confusion with the perlwin32 documentation on 8.3-restricted filesystems.\n"
                },
                {
                    "name": "Performance Enhancements",
                    "content": "•   map() could get pathologically slow when the result list it generates is larger than the\nsource list.  The performance has been improved for common scenarios. [561]\n\n•   sort() is also fully reentrant, in the sense that the sort function can itself call\nsort().  This did not work reliably in previous releases. [561]\n\n•   sort() has been changed to use primarily mergesort internally as opposed to the earlier\nquicksort.  For very small lists this may result in slightly slower sorting times, but in\ngeneral the speedup should be at least 20%.  Additional bonuses are that the worst case\nbehaviour of sort() is now better (in computer science terms it now runs in time O(N log\nN), as opposed to quicksort's Theta(N2) worst-case run time behaviour), and that sort()\nis now stable (meaning that elements with identical keys will stay ordered as they were\nbefore the sort).  See the \"sort\" pragma for information.\n\nThe story in more detail: suppose you want to serve yourself a little slice of Pi.\n\n@digits = ( 3,1,4,1,5,9 );\n\nA numerical sort of the digits will yield (1,1,3,4,5,9), as expected.  Which 1 comes\nfirst is hard to know, since one 1 looks pretty much like any other.  You can regard this\nas totally trivial, or somewhat profound.  However, if you just want to sort the even\ndigits ahead of the odd ones, then what will\n\nsort { ($a % 2) <=> ($b % 2) } @digits;\n\nyield?  The only even digit, 4, will come first.  But how about the odd numbers, which\nall compare equal?  With the quicksort algorithm used to implement Perl 5.6 and earlier,\nthe order of ties is left up to the sort.  So, as you add more and more digits of Pi, the\norder in which the sorted even and odd digits appear will change.  and, for sufficiently\nlarge slices of Pi, the quicksort algorithm in Perl 5.8 won't return the same results\neven if reinvoked with the same input.  The justification for this rests with quicksort's\nworst case behavior.  If you run\n\nsort { $a <=> $b } ( 1 .. $N , 1 .. $N );\n\n(something you might approximate if you wanted to merge two sorted arrays using sort),\ndoubling $N doesn't just double the quicksort time, it quadruples it.  Quicksort has a\nworst case run time that can grow like N2, so-called quadratic behaviour, and it can\nhappen on patterns that may well arise in normal use.  You won't notice this for small\narrays, but you will notice it with larger arrays, and you may not live long enough for\nthe sort to complete on arrays of a million elements.  So the 5.8 quicksort scrambles\nlarge arrays before sorting them, as a statistical defence against quadratic behaviour.\nBut that means if you sort the same large array twice, ties may be broken in different\nways.\n\nBecause of the unpredictability of tie-breaking order, and the quadratic worst-case\nbehaviour, quicksort was almost replaced completely with a stable mergesort.  Stable\nmeans that ties are broken to preserve the original order of appearance in the input\narray.  So\n\nsort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9);\n\nwill yield (4,3,1,1,5,9), guaranteed.  The even and odd numbers appear in the output in\nthe same order they appeared in the input.  Mergesort has worst case O(N log N)\nbehaviour, the best value attainable.  And, ironically, this mergesort does particularly\nwell where quicksort goes quadratic:  mergesort sorts (1..$N, 1..$N) in O(N) time.  But\nquicksort was rescued at the last moment because it is faster than mergesort on certain\ninputs and platforms.  For example, if you really don't care about the order of even and\nodd digits, quicksort will run in O(N) time; it's very good at sorting many repetitions\nof a small number of distinct elements.  The quicksort divide and conquer strategy works\nwell on platforms with relatively small, very fast, caches.  Eventually, the problem gets\nwhittled down to one that fits in the cache, from which point it benefits from the\nincreased memory speed.\n\nQuicksort was rescued by implementing a sort pragma to control aspects of the sort.  The\nstable subpragma forces stable behaviour, regardless of algorithm.  The quicksort and\nmergesort subpragmas are heavy-handed ways to select the underlying implementation.  The\nleading \"\" is a reminder that these subpragmas may not survive beyond 5.8.  More\nappropriate mechanisms for selecting the implementation exist, but they wouldn't have\narrived in time to save quicksort.\n\n•   Hashes now use Bob Jenkins \"One-at-a-Time\" hashing key algorithm (\nhttp://burtleburtle.net/bob/hash/doobs.html ).  This algorithm is reasonably fast while\nproducing a much better spread of values than the old hashing algorithm (originally by\nChris Torek, later tweaked by Ilya Zakharevich).  Hash values output from the algorithm\non a hash of all 3-char printable ASCII keys comes much closer to passing the DIEHARD\nrandom number generation tests.  According to perlbench, this change has not affected the\noverall speed of Perl.\n\n•   unshift() should now be noticeably faster.\n"
                },
                {
                    "name": "Installation and Configuration Improvements",
                    "content": ""
                },
                {
                    "name": "Generic Improvements",
                    "content": "•   INSTALL now explains how you can configure Perl to use 64-bit integers even on non-64-bit\nplatforms.\n\n•   Policy.sh policy change: if you are reusing a Policy.sh file (see INSTALL) and you use\nConfigure -Dprefix=/foo/bar and in the old Policy $prefix eq $siteprefix and $prefix eq\n$vendorprefix, all of them will now be changed to the new prefix, /foo/bar.  (Previously\nonly $prefix changed.)  If you do not like this new behaviour, specify prefix,\nsiteprefix, and vendorprefix explicitly.\n\n•   A new optional location for Perl libraries, otherlibdirs, is available.  It can be used\nfor example for vendor add-ons without disturbing Perl's own library directories.\n\n•   In many platforms, the vendor-supplied 'cc' is too stripped-down to build Perl\n(basically, 'cc' doesn't do ANSI C).  If this seems to be the case and 'cc' does not seem\nto be the GNU C compiler 'gcc', an automatic attempt is made to find and use 'gcc'\ninstead.\n\n•   gcc needs to closely track the operating system release to avoid build problems. If\nConfigure finds that gcc was built for a different operating system release than is\nrunning, it now gives a clearly visible warning that there may be trouble ahead.\n\n•   Since Perl 5.8 is not binary-compatible with previous releases of Perl, Configure no\nlonger suggests including the 5.005 modules in @INC.\n\n•   Configure \"-S\" can now run non-interactively. [561]\n\n•   Configure support for pdp11-style memory models has been removed due to obsolescence.\n[561]\n\n•   configure.gnu now works with options with whitespace in them.\n\n•   installperl now outputs everything to STDERR.\n\n•   Because PerlIO is now the default on most platforms, \"-perlio\" doesn't get appended to\nthe $Config{archname} (also known as $^O) anymore.  Instead, if you explicitly choose not\nto use perlio (Configure command line option -Uuseperlio), you will get \"-stdio\"\nappended.\n\n•   Another change related to the architecture name is that \"-64all\" (-Duse64bitall, or\n\"maximally 64-bit\") is appended only if your pointers are 64 bits wide.  (To be exact,\nthe use64bitall is ignored.)\n\n•   In AFS installations, one can configure the root of the AFS to be somewhere else than the\ndefault /afs by using the Configure parameter \"-Dafsroot=/some/where/else\".\n\n•   APPLLIBEXP, a lesser-known configuration-time definition, has been documented.  It can\nbe used to prepend site-specific directories to Perl's default search path (@INC); see\nINSTALL for information.\n\n•   The version of Berkeley DB used when the Perl (and, presumably, the DBFile extension)\nwas built is now available as @Config{qw(dbversionmajor dbversionminor\ndbversionpatch)} from Perl and as \"DBVERSIONMAJORCFG DBVERSIONMINORCFG\nDBVERSIONPATCHCFG\" from C.\n\n•   Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM has been documented\nin INSTALL.\n\n•   If you have CPAN access (either network or a local copy such as a CD-ROM) you can during\nspecify extra modules to Configure to build and install with Perl using the -Dextras=...\noption.  See INSTALL for more details.\n\n•   In addition to config.over, a new override file, config.arch, is available.  This file is\nsupposed to be used by hints file writers for architecture-wide changes (as opposed to\nconfig.over which is for site-wide changes).\n\n•   If your file system supports symbolic links, you can build Perl outside of the source\ndirectory by\n\nmkdir perl/build/directory\ncd perl/build/directory\nsh /path/to/perl/source/Configure -Dmksymlinks ...\n\nThis will create in perl/build/directory a tree of symbolic links pointing to files in\n/path/to/perl/source.  The original files are left unaffected.  After Configure has\nfinished, you can just say\n\nmake all test\n\nand Perl will be built and tested, all in perl/build/directory.  [561]\n\n•   For Perl developers, several new make targets for profiling and debugging have been\nadded; see perlhack.\n\n•       Use of the gprof tool to profile Perl has been documented in perlhack.  There is\na make target called \"perl.gprof\" for generating a gprofiled Perl executable.\n\n•       If you have GCC 3, there is a make target called \"perl.gcov\" for creating a\ngcoved Perl executable for coverage analysis.  See perlhack.\n\n•       If you are on IRIX or Tru64 platforms, new profiling/debugging options have been\nadded; see perlhack for more information about pixie and Third Degree.\n\n•   Guidelines of how to construct minimal Perl installations have been added to INSTALL.\n\n•   The Thread extension is now not built at all under ithreads (\"Configure -Duseithreads\")\nbecause it wouldn't work anyway (the Thread extension requires being Configured with\n\"-Duse5005threads\").\n\nNote that the 5.005 threads are unsupported and deprecated: if you have code written for\nthe old threads you should migrate it to the new ithreads model.\n\n•   The Gconvert macro ($Config{dGconvert}) used by perl for stringifying floating-point\nnumbers is now more picky about using sprintf %.*g rules for the conversion.  Some\nplatforms that used to use gcvt may now resort to the slower sprintf.\n\n•   The obsolete method of making a special (e.g., debugging) flavor of perl by saying\n\nmake LIBPERL=libperld.a\n\nhas been removed. Use -DDEBUGGING instead.\n"
                },
                {
                    "name": "New Or Improved Platforms",
                    "content": "For the list of platforms known to support Perl, see \"Supported Platforms\" in perlport.\n\n•   AIX dynamic loading should be now better supported.\n\n•   AIX should now work better with gcc, threads, and 64-bitness.  Also the long doubles\nsupport in AIX should be better now.  See perlaix.\n\n•   AtheOS ( http://www.atheos.cx/ ) is a new platform.\n\n•   BeOS has been reclaimed.\n\n•   The DG/UX platform now supports 5.005-style threads.  See perldgux.\n\n•   The DYNIX/ptx platform (also known as dynixptx) is supported at or near osvers 4.5.2.\n\n•   EBCDIC platforms (z/OS (also known as OS/390), POSIX-BC, and VM/ESA) have been regained.\nMany test suite tests still fail and the co-existence of Unicode and EBCDIC isn't quite\nsettled, but the situation is much better than with Perl 5.6.  See perlos390, perlbs2000\n(for POSIX-BC), and perlvmesa for more information.  (Note: support for VM/ESA was\nremoved in Perl v5.18.0. The relevant information was in README.vmesa)\n\n•   Building perl with -Duseithreads or -Duse5005threads now works under HP-UX 10.20\n(previously it only worked under 10.30 or later). You will need a thread library package\ninstalled. See README.hpux. [561]\n\n•   Mac OS Classic is now supported in the mainstream source package (MacPerl has of course\nbeen available since perl 5.004 but now the source code bases of standard Perl and\nMacPerl have been synchronised) [561]\n\n•   Mac OS X (or Darwin) should now be able to build Perl even on HFS+ filesystems.  (The\ncase-insensitivity used to confuse the Perl build process.)\n\n•   NCR MP-RAS is now supported. [561]\n\n•   All the NetBSD specific patches (except for the installation specific ones) have been\nmerged back to the main distribution.\n\n•   NetWare from Novell is now supported.  See perlnetware.\n\n•   NonStop-UX is now supported. [561]\n\n•   NEC SUPER-UX is now supported.\n\n•   All the OpenBSD specific patches (except for the installation specific ones) have been\nmerged back to the main distribution.\n\n•   Perl has been tested with the GNU pth userlevel thread package (\nhttp://www.gnu.org/software/pth/pth.html ).  All thread tests of Perl now work, but not\nwithout adding some yield()s to the tests, so while pth (and other userlevel thread\nimplementations) can be considered to be \"working\" with Perl ithreads, keep in mind the\npossible non-preemptability of the underlying thread implementation.\n\n•   Stratus VOS is now supported using Perl's native build method (Configure).  This is the\nrecommended method to build Perl on VOS.  The older methods, which build miniperl, are\nstill available.  See perlvos. [561+]\n\n•   The Amdahl UTS Unix mainframe platform is now supported. [561]\n\n•   WinCE is now supported.  See perlce.\n\n•   z/OS (formerly known as OS/390, formerly known as MVS OE) now has support for dynamic\nloading.  This is not selected by default, however, you must specify -Dusedl in the\narguments of Configure. [561]\n"
                },
                {
                    "name": "Selected Bug Fixes",
                    "content": "Numerous memory leaks and uninitialized memory accesses have been hunted down.  Most\nimportantly, anonymous subs used to leak quite a bit. [561]\n\n•   The autouse pragma didn't work for Multi::Part::Function::Names.\n\n•   caller() could cause core dumps in certain situations.  Carp was sometimes affected by\nthis problem.  In particular, caller() now returns a subroutine name of \"(unknown)\" for\nsubroutines that have been removed from the symbol table.\n\n•   chop(@list) in list context returned the characters chopped in reverse order.  This has\nbeen reversed to be in the right order. [561]\n\n•   Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm) when building the\nPerl binary.  The only exception to this is SunOS 4.x, which needs them. [561]\n\n•   The behaviour of non-decimal but numeric string constants such as \"0x23\" was platform-\ndependent: in some platforms that was seen as 35, in some as 0, in some as a floating\npoint number (don't ask).  This was caused by Perl's using the operating system libraries\nin a situation where the result of the string to number conversion is undefined: now Perl\nconsistently handles such strings as zero in numeric contexts.\n\n•   Several debugger fixes: exit code now reflects the script exit code, condition \"0\" now\ntreated correctly, the \"d\" command now checks line number, $. no longer gets corrupted,\nand all debugger output now goes correctly to the socket if RemotePort is set. [561]\n\n•   The debugger (perl5db.pl) has been modified to present a more consistent commands\ninterface, via (CommandSet=580).  perl5db.t was also added to test the changes, and as a\nplaceholder for further tests.\n\nSee perldebug.\n\n•   The debugger has a new \"dumpDepth\" option to control the maximum depth to which nested\nstructures are dumped.  The \"x\" command has been extended so that \"x N EXPR\" dumps out\nthe value of EXPR to a depth of at most N levels.\n\n•   The debugger can now show lexical variables if you have the CPAN module PadWalker\ninstalled.\n\n•   The order of DESTROYs has been made more predictable.\n\n•   Perl 5.6.0 could emit spurious warnings about redefinition of dlerror() when statically\nbuilding extensions into perl.  This has been corrected. [561]\n\n•   dprofpp -R didn't work.\n\n•   *foo{FORMAT} now works.\n\n•   Infinity is now recognized as a number.\n\n•   UNIVERSAL::isa no longer caches methods incorrectly.  (This broke the Tk extension with\n5.6.0.) [561]\n\n•   Lexicals I: lexicals outside an eval \"\" weren't resolved correctly inside a subroutine\ndefinition inside the eval \"\" if they were not already referenced in the top level of the\neval\"\"ed code.\n\n•   Lexicals II: lexicals leaked at file scope into subroutines that were declared before the\nlexicals.\n\n•   Lexical warnings now propagating correctly between scopes and into \"eval \"...\"\".\n\n•   \"use warnings qw(FATAL all)\" did not work as intended.  This has been corrected. [561]\n\n•   warnings::enabled() now reports the state of $^W correctly if the caller isn't using\nlexical warnings. [561]\n\n•   Line renumbering with eval and \"#line\" now works. [561]\n\n•   Fixed numerous memory leaks, especially in eval \"\".\n\n•   Localised tied variables no longer leak memory\n\nuse Tie::Hash;\ntie my %tiedhash => 'Tie::StdHash';\n\n...\n\n# Used to leak memory every time local() was called;\n# in a loop, this added up.\nlocal($tiedhash{Foo}) = 1;\n\n•   Localised hash elements (and %ENV) are correctly unlocalised to not exist, if they didn't\nbefore they were localised.\n\nuse Tie::Hash;\ntie my %tiedhash => 'Tie::StdHash';\n\n...\n\n# Nothing has set the FOO element so far\n\n{ local $tiedhash{FOO} = 'Bar' }\n\n# This used to print, but not now.\nprint \"exists!\\n\" if exists $tiedhash{FOO};\n\nAs a side effect of this fix, tied hash interfaces must define the EXISTS and DELETE\nmethods.\n\n•   mkdir() now ignores trailing slashes in the directory name, as mandated by POSIX.\n\n•   Some versions of glibc have a broken modfl().  This affects builds with\n\"-Duselongdouble\".  This version of Perl detects this brokenness and has a workaround for\nit.  The glibc release 2.2.2 is known to have fixed the modfl() bug.\n\n•   Modulus of unsigned numbers now works (4063328477 % 65535 used to return 27406, instead\nof 27047). [561]\n\n•   Some \"not a number\" warnings introduced in 5.6.0 eliminated to be more compatible with\n5.005.  Infinity is now recognised as a number. [561]\n\n•   Numeric conversions did not recognize changes in the string value properly in certain\ncircumstances. [561]\n\n•   Attributes (such as :shared) didn't work with our().\n\n•   our() variables will not cause bogus \"Variable will not stay shared\" warnings. [561]\n\n•   \"our\" variables of the same name declared in two sibling blocks resulted in bogus\nwarnings about \"redeclaration\" of the variables.  The problem has been corrected. [561]\n\n•   pack \"Z\" now correctly terminates the string with \"\\0\".\n\n•   Fix password routines which in some shadow password platforms (e.g. HP-UX) caused\ngetpwent() to return every other entry.\n\n•   The PERL5OPT environment variable (for passing command line arguments to Perl) didn't\nwork for more than a single group of options. [561]\n\n•   PERL5OPT with embedded spaces didn't work.\n\n•   printf() no longer resets the numeric locale to \"C\".\n\n•   \"qw(a\\\\b)\" now parses correctly as 'a\\\\b': that is, as three characters, not four. [561]\n\n•   pos() did not return the correct value within s///ge in earlier versions.  This is now\nhandled correctly. [561]\n\n•   Printing quads (64-bit integers) with printf/sprintf now works without the q L ll\nprefixes (assuming you are on a quad-capable platform).\n\n•   Regular expressions on references and overloaded scalars now work. [561+]\n\n•   Right-hand side magic (GMAGIC) could in many cases such as string concatenation be\ninvoked too many times.\n\n•   scalar() now forces scalar context even when used in void context.\n\n•   SOCKS support is now much more robust.\n\n•   sort() arguments are now compiled in the right wantarray context (they were accidentally\nusing the context of the sort() itself).  The comparison block is now run in scalar\ncontext, and the arguments to be sorted are always provided list context. [561]\n\n•   Changed the POSIX character class \"[[:space:]]\" to include the (very rarely used)\nvertical tab character.  Added a new POSIX-ish character class \"[[:blank:]]\" which stands\nfor horizontal whitespace (currently, the space and the tab).\n\n•   The tainting behaviour of sprintf() has been rationalized.  It does not taint the result\nof floating point formats anymore, making the behaviour consistent with that of string\ninterpolation. [561]\n\n•   Some cases of inconsistent taint propagation (such as within hash values) have been\nfixed.\n\n•   The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds of simple pattern\nmatches.  These are now handled better. [561]\n\n•   Regular expression debug output (whether through \"use re 'debug'\" or via \"-Dr\") now looks\nbetter. [561]\n\n•   Multi-line matches like \"\"a\\nxb\\n\" =~ /(?!\\A)x/m\" were flawed.  The bug has been fixed.\n[561]\n\n•   Use of $& could trigger a core dump under some situations.  This is now avoided. [561]\n\n•   The regular expression captured submatches ($1, $2, ...) are now more consistently unset\nif the match fails, instead of leaving false data lying around in them. [561]\n\n•   readline() on files opened in \"slurp\" mode could return an extra \"\" (blank line) at the\nend in certain situations.  This has been corrected. [561]\n\n•   Autovivification of symbolic references of special variables described in perlvar (as in\n\"${$num}\") was accidentally disabled.  This works again now. [561]\n\n•   Sys::Syslog ignored the \"LOGAUTH\" constant.\n\n•   $AUTOLOAD, sort(), lock(), and spawning subprocesses in multiple threads simultaneously\nare now thread-safe.\n\n•   Tie::Array's SPLICE method was broken.\n\n•   Allow a read-only string on the left-hand side of a non-modifying tr///.\n\n•   If \"STDERR\" is tied, warnings caused by \"warn\" and \"die\" now correctly pass to it.\n\n•   Several Unicode fixes.\n\n•       BOMs (byte order marks) at the beginning of Perl files (scripts, modules) should\nnow be transparently skipped.  UTF-16 and UCS-2 encoded Perl files should now be\nread correctly.\n\n•       The character tables have been updated to Unicode 3.2.0.\n\n•       Comparing with utf8 data does not magically upgrade non-utf8 data into utf8.\n(This was a problem for example if you were mixing data from I/O and Unicode\ndata: your output might have got magically encoded as UTF-8.)\n\n•       Generating illegal Unicode code points such as U+FFFE, or the UTF-16 surrogates,\nnow also generates an optional warning.\n\n•       \"IsAlnum\", \"IsAlpha\", and \"IsWord\" now match titlecase.\n\n•       Concatenation with the \".\" operator or via variable interpolation, \"eq\",\n\"substr\", \"reverse\", \"quotemeta\", the \"x\" operator, substitution with \"s///\",\nsingle-quoted UTF-8, should now work.\n\n•       The \"tr///\" operator now works.  Note that the \"tr///CU\" functionality has been\nremoved (but see pack('U0', ...)).\n\n•       \"eval \"v200\"\" now works.\n\n•       Perl 5.6.0 parsed m/\\x{ab}/ incorrectly, leading to spurious warnings.  This has\nbeen corrected. [561]\n\n•       Zero entries were missing from the Unicode classes such as \"IsDigit\".\n\n•   Large unsigned numbers (those above 231) could sometimes lose their unsignedness,\ncausing bogus results in arithmetic operations. [561]\n\n•   The Perl parser has been stress tested using both random input and Markov chain input and\nthe few found crashes and lockups have been fixed.\n"
                },
                {
                    "name": "Platform Specific Changes and Fixes",
                    "content": "•   BSDI 4.*\n\nPerl now works on post-4.0 BSD/OSes.\n\n•   All BSDs\n\nSetting $0 now works (as much as possible; see perlvar for details).\n\n•   Cygwin\n\nNumerous updates; currently synchronised with Cygwin 1.3.10.\n\n•   Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.\n\n•   EPOC\n\nEPOC now better supported.  See README.epoc. [561]\n\n•   FreeBSD 3.*\n\nPerl now works on post-3.0 FreeBSDs.\n\n•   HP-UX\n\nREADME.hpux updated; \"Configure -Duse64bitall\" now works; now uses HP-UX malloc instead\nof Perl malloc.\n\n•   IRIX\n\nNumerous compilation flag and hint enhancements; accidental mixing of 32-bit and 64-bit\nlibraries (a doomed attempt) made much harder.\n\n•   Linux\n\n•       Long doubles should now work (see INSTALL). [561]\n\n•       Linux previously had problems related to sockaddrlen when using accept(),\nrecvfrom() (in Perl: recv()), getpeername(), and getsockname().\n\n•   Mac OS Classic\n\nCompilation of the standard Perl distribution in Mac OS Classic should now work if you\nhave the Metrowerks development environment and the missing Mac-specific toolkit bits.\nContact the macperl mailing list for details.\n\n•   MPE/iX\n\nMPE/iX update after Perl 5.6.0.  See README.mpeix. [561]\n\n•   NetBSD/threads: try installing the GNU pth (should be in the packages collection, or\nhttp://www.gnu.org/software/pth/), and Configure with -Duseithreads.\n\n•   NetBSD/sparc\n\nPerl now works on NetBSD/sparc.\n\n•   OS/2\n\nNow works with usethreads (see INSTALL). [561]\n\n•   Solaris\n\n64-bitness using the Sun Workshop compiler now works.\n\n•   Stratus VOS\n\nThe native build method requires at least VOS Release 14.5.0 and GNU C++/GNU Tools 2.0.1\nor later.  The Perl pack function now maps overflowed values to +infinity and underflowed\nvalues to -infinity.\n\n•   Tru64 (aka Digital UNIX, aka DEC OSF/1)\n\nThe operating system version letter now recorded in $Config{osvers}.  Allow compiling\nwith gcc (previously explicitly forbidden).  Compiling with gcc still not recommended\nbecause buggy code results, even with gcc 2.95.2.\n\n•   Unicos\n\nFixed various alignment problems that lead into core dumps either during build or later;\nno longer dies on math errors at runtime; now using full quad integers (64 bits),\npreviously was using only 46 bit integers for speed.\n\n•   VMS\n\nSee \"Socket Extension Dynamic in VMS\" and \"IEEE-format Floating Point Default on OpenVMS\nAlpha\" for important changes not otherwise listed here.\n\nchdir() now works better despite a CRT bug; now works with MULTIPLICITY (see INSTALL);\nnow works with Perl's malloc.\n\nThe tainting of %ENV elements via \"keys\" or \"values\" was previously unimplemented.  It\nnow works as documented.\n\nThe \"waitpid\" emulation has been improved.  The worst bug (now fixed) was that a pid of\n-1 would cause a wildcard search of all processes on the system.\n\nPOSIX-style signals are now emulated much better on VMS versions prior to 7.0.\n\nThe \"system\" function and backticks operator have improved functionality and better error\nhandling. [561]\n\nFile access tests now use current process privileges rather than the user's default\nprivileges, which could sometimes result in a mismatch between reported access and actual\naccess.  This improvement is only available on VMS v6.0 and later.\n\nThere is a new \"kill\" implementation based on \"sys$sigprc\" that allows older VMS systems\n(pre-7.0) to use \"kill\" to send signals rather than simply force exit.  This\nimplementation also allows later systems to call \"kill\" from within a signal handler.\n\nIterative logical name translations are now limited to 10 iterations in imitation of SHOW\nLOGICAL and other OpenVMS facilities.\n\n•   Windows\n\n•       Signal handling now works better than it used to.  It is now implemented using a\nWindows message loop, and is therefore less prone to random crashes.\n\n•       fork() emulation is now more robust, but still continues to have a few esoteric\nbugs and caveats.  See perlfork for details. [561+]\n\n•       A failed (pseudo)fork now returns undef and sets errno to EAGAIN. [561]\n\n•       The following modules now work on Windows:\n\nExtUtils::Embed         [561]\nIO::Pipe\nIO::Poll\nNet::Ping\n\n•       IO::File::newtmpfile() is no longer limited to 32767 invocations per-process.\n\n•       Better chdir() return value for a non-existent directory.\n\n•       Compiling perl using the 64-bit Platform SDK tools is now supported.\n\n•       The Win32::SetChildShowWindow() builtin can be used to control the visibility of\nwindows created by child processes.  See Win32 for details.\n\n•       Non-blocking waits for child processes (or pseudo-processes) are supported via\n\"waitpid($pid, &POSIX::WNOHANG)\".\n\n•       The behavior of system() with multiple arguments has been rationalized.  Each\nunquoted argument will be automatically quoted to protect whitespace, and any\nexisting whitespace in the arguments will be preserved.  This improves the\nportability of system(@args) by avoiding the need for Windows \"cmd\" shell\nspecific quoting in perl programs.\n\nNote that this means that some scripts that may have relied on earlier buggy\nbehavior may no longer work correctly.  For example, \"system(\"nmake /nologo\",\n@args)\" will now attempt to run the file \"nmake /nologo\" and will fail when such\na file isn't found.  On the other hand, perl will now execute code such as\n\"system(\"c:/Program Files/MyApp/foo.exe\", @args)\" correctly.\n\n•       The perl header files no longer suppress common warnings from the Microsoft\nVisual C++ compiler.  This means that additional warnings may now show up when\ncompiling XS code.\n\n•       Borland C++ v5.5 is now a supported compiler that can build Perl.  However, the\ngenerated binaries continue to be incompatible with those generated by the other\nsupported compilers (GCC and Visual C++). [561]\n\n•       Duping socket handles with open(F, \">&MYSOCK\") now works under Windows 9x.  [561]\n\n•       Current directory entries in %ENV are now correctly propagated to child\nprocesses. [561]\n\n•       New %ENV entries now propagate to subprocesses. [561]\n\n•       Win32::GetCwd() correctly returns C:\\ instead of C: when at the drive root.\nOther bugs in chdir() and Cwd::cwd() have also been fixed. [561]\n\n•       The makefiles now default to the features enabled in ActiveState ActivePerl (a\npopular Win32 binary distribution). [561]\n\n•       HTML files will now be installed in c:\\perl\\html instead of c:\\perl\\lib\\pod\\html\n\n•       REGEXPANDSZ keys are now allowed in registry settings used by perl. [561]\n\n•       Can now send() from all threads, not just the first one. [561]\n\n•       ExtUtils::MakeMaker now uses $ENV{LIB} to search for libraries. [561]\n\n•       Less stack reserved per thread so that more threads can run concurrently. (Still\n16M per thread.) [561]\n\n•       \"File::Spec->tmpdir()\" now prefers C:/temp over /tmp (works better when perl is\nrunning as service).\n\n•       Better UNC path handling under ithreads. [561]\n\n•       wait(), waitpid(), and backticks now return the correct exit status under Windows\n9x. [561]\n\n•       A socket handle leak in accept() has been fixed. [561]\n"
                },
                {
                    "name": "New or Changed Diagnostics",
                    "content": "Please see perldiag for more details.\n\n•   Ambiguous range in the transliteration operator (like a-z-9) now gives a warning.\n\n•   chdir(\"\") and chdir(undef) now give a deprecation warning because they cause a possible\nunintentional chdir to the home directory.  Say chdir() if you really mean that.\n\n•   Two new debugging options have been added: if you have compiled your Perl with debugging,\nyou can use the -DT [561] and -DR options to trace tokenising and to add reference counts\nto displaying variables, respectively.\n\n•   The lexical warnings category \"deprecated\" is no longer a sub-category of the \"syntax\"\ncategory. It is now a top-level category in its own right.\n\n•   Unadorned dump() will now give a warning suggesting to use explicit CORE::dump() if\nthat's what really is meant.\n\n•   The \"Unrecognized escape\" warning has been extended to include \"\\8\", \"\\9\", and \"\\\".\nThere is no need to escape any of the \"\\w\" characters.\n\n•   All regular expression compilation error messages are now hopefully easier to understand\nboth because the error message now comes before the failed regex and because the point of\nfailure is now clearly marked by a \"<-- HERE\" marker.\n\n•   Various I/O (and socket) functions like binmode(), close(), and so forth now more\nconsistently warn if they are used illogically either on a yet unopened or on an already\nclosed filehandle (or socket).\n\n•   Using lstat() on a filehandle now gives a warning.  (It's a non-sensical thing to do.)\n\n•   The \"-M\" and \"-m\" options now warn if you didn't supply the module name.\n\n•   If you in \"use\" specify a required minimum version, modules matching the name and but not\ndefining a $VERSION will cause a fatal failure.\n\n•   Using negative offset for vec() in lvalue context is now a warnable offense.\n\n•   Odd number of arguments to overload::constant now elicits a warning.\n\n•   Odd number of elements in anonymous hash now elicits a warning.\n\n•   The various \"opened only for\", \"on closed\", \"never opened\" warnings drop the \"main::\"\nprefix for filehandles in the \"main\" package, for example \"STDIN\" instead of\n\"main::STDIN\".\n\n•   Subroutine prototypes are now checked more carefully, you may get warnings for example if\nyou have used non-prototype characters.\n\n•   If an attempt to use a (non-blessed) reference as an array index is made, a warning is\ngiven.\n\n•   \"push @a;\" and \"unshift @a;\" (with no values to push or unshift) now give a warning.\nThis may be a problem for generated and eval'ed code.\n\n•   If you try to \"pack\" in perlfunc a number less than 0 or larger than 255 using the \"C\"\nformat you will get an optional warning.  Similarly for the \"c\" format and a number less\nthan -128 or more than 127.\n\n•   pack \"P\" format now demands an explicit size.\n\n•   unpack \"w\" now warns of unterminated compressed integers.\n\n•   Warnings relating to the use of PerlIO have been added.\n\n•   Certain regex modifiers such as \"(?o)\" make sense only if applied to the entire regex.\nYou will get an optional warning if you try to do otherwise.\n\n•   Variable length lookbehind has not yet been implemented, trying to use it will tell that.\n\n•   Using arrays or hashes as references (e.g. \"%foo->{bar}\" has been deprecated for a while.\nNow you will get an optional warning.\n\n•   Warnings relating to the use of the new restricted hashes feature have been added.\n\n•   Self-ties of arrays and hashes are not supported and fatal errors will happen even at an\nattempt to do so.\n\n•   Using \"sort\" in scalar context now issues an optional warning.  This didn't do anything\nuseful, as the sort was not performed.\n\n•   Using the /g modifier in split() is meaningless and will cause a warning.\n\n•   Using splice() past the end of an array now causes a warning.\n\n•   Malformed Unicode encodings (UTF-8 and UTF-16) cause a lot of warnings, as does trying to\nuse UTF-16 surrogates (which are unimplemented).\n\n•   Trying to use Unicode characters on an I/O stream without marking the stream's encoding\n(using open() or binmode()) will cause \"Wide character\" warnings.\n\n•   Use of v-strings in use/require causes a (backward) portability warning.\n\n•   Warnings relating to the use interpreter threads and their shared data have been added.\n"
                },
                {
                    "name": "Changed Internals",
                    "content": "•   PerlIO is now the default.\n\n•   perlapi.pod (a companion to perlguts) now attempts to document the internal API.\n\n•   You can now build a really minimal perl called microperl.  Building microperl does not\nrequire even running Configure; \"make -f Makefile.micro\" should be enough.  Beware:\nmicroperl makes many assumptions, some of which may be too bold; the resulting executable\nmay crash or otherwise misbehave in wondrous ways.  For careful hackers only.\n\n•   Added rsignal(), whichsig(), dojoin(), opclear, opnull, ptrtableclear(),\nptrtablefree(), svsetrefuv(), and several UTF-8 interfaces to the publicised API.\nFor the full list of the available APIs see perlapi.\n\n•   Made possible to propagate customised exceptions via croak()ing.\n\n•   Now xsubs can have attributes just like subs.  (Well, at least the built-in attributes.)\n\n•   dTHR and djSP have been obsoleted; the former removed (because it's a no-op) and the\nlatter replaced with dSP.\n\n•   PERLOBJECT has been completely removed.\n\n•   The MAGIC constants (e.g. 'P') have been macrofied (e.g. \"PERLMAGICTIED\") for better\nsource code readability and maintainability.\n\n•   The regex compiler now maintains a structure that identifies nodes in the compiled\nbytecode with the corresponding syntactic features of the original regex expression.  The\ninformation is attached to the new \"offsets\" member of the \"struct regexp\". See\nperldebguts for more complete information.\n\n•   The C code has been made much more \"gcc -Wall\" clean.  Some warning messages still remain\nin some platforms, so if you are compiling with gcc you may see some warnings about\ndubious practices.  The warnings are being worked on.\n\n•   perly.c, sv.c, and sv.h have now been extensively commented.\n\n•   Documentation on how to use the Perl source repository has been added to\nPorting/repository.pod.\n\n•   There are now several profiling make targets.\n"
                },
                {
                    "name": "Security Vulnerability Closed [561]",
                    "content": "(This change was already made in 5.7.0 but bears repeating here.)  (5.7.0 came out before\n5.6.1: the development branch 5.7 released earlier than the maintenance branch 5.6)\n\nA potential security vulnerability in the optional suidperl component of Perl was identified\nin August 2000.  suidperl is neither built nor installed by default.  As of November 2001 the\nonly known vulnerable platform is Linux, most likely all Linux distributions.  CERT and\nvarious vendors and distributors have been alerted about the vulnerability.  See\nhttp://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt for more information.\n\nThe problem was caused by Perl trying to report a suspected security exploit attempt using an\nexternal program, /bin/mail.  On Linux platforms the /bin/mail program had an undocumented\nfeature which when combined with suidperl gave access to a root shell, resulting in a serious\ncompromise instead of reporting the exploit attempt.  If you don't have /bin/mail, or if you\nhave 'safe setuid scripts', or if suidperl is not installed, you are safe.\n\nThe exploit attempt reporting feature has been completely removed from Perl 5.8.0 (and the\nmaintenance release 5.6.1, and it was removed also from all the Perl 5.7 releases), so that\nparticular vulnerability isn't there anymore.  However, further security vulnerabilities are,\nunfortunately, always possible.  The suidperl functionality is most probably going to be\nremoved in Perl 5.10.  In any case, suidperl should only be used by security experts who know\nexactly what they are doing and why they are using suidperl instead of some other solution\nsuch as sudo ( see http://www.courtesan.com/sudo/ ).\n"
                },
                {
                    "name": "New Tests",
                    "content": "Several new tests have been added, especially for the lib and ext subsections.  There are now\nabout 69 000 individual tests (spread over about 700 test scripts), in the regression suite\n(5.6.1 has about 11 700 tests, in 258 test scripts)  The exact numbers depend on the platform\nand Perl configuration used.  Many of the new tests are of course introduced by the new\nmodules, but still in general Perl is now more thoroughly tested.\n\nBecause of the large number of tests, running the regression suite will take considerably\nlonger time than it used to: expect the suite to take up to 4-5 times longer to run than in\nperl 5.6.  On a really fast machine you can hope to finish the suite in about 6-8 minutes\n(wallclock time).\n\nThe tests are now reported in a different order than in earlier Perls.  (This happens because\nthe test scripts from under t/lib have been moved to be closer to the library/extension they\nare testing.)\n"
                },
                {
                    "name": "Known Problems",
                    "content": ""
                },
                {
                    "name": "The Compiler Suite Is Still Very Experimental",
                    "content": "The compiler suite is slowly getting better but it continues to be highly experimental.  Use\nin production environments is discouraged.\n"
                },
                {
                    "name": "Localising Tied Arrays and Hashes Is Broken",
                    "content": "local %tiedarray;\n\ndoesn't work as one would expect: the old value is restored incorrectly.  This will be\nchanged in a future release, but we don't know yet what the new semantics will exactly be.\nIn any case, the change will break existing code that relies on the current (ill-defined)\nsemantics, so just avoid doing this in general.\n"
                },
                {
                    "name": "Building Extensions Can Fail Because Of Largefiles",
                    "content": "Some extensions like modperl are known to have issues with `largefiles', a change brought by\nPerl 5.6.0 in which file offsets default to 64 bits wide, where supported.  Modules may fail\nto compile at all, or they may compile and work incorrectly.  Currently, there is no good\nsolution for the problem, but Configure now provides appropriate non-largefile ccflags,\nldflags, libswanted, and libs in the %Config hash (e.g., $Config{ccflagsnolargefiles}) so\nthe extensions that are having problems can try configuring themselves without the\nlargefileness.  This is admittedly not a clean solution, and the solution may not even work\nat all.  One potential failure is whether one can (or, if one can, whether it's a good idea\nto) link together at all binaries with different ideas about file offsets; all this is\nplatform-dependent.\n\nModifying $ Inside for(..)\nfor (1..5) { $++ }\n\nworks without complaint.  It shouldn't.  (You should be able to modify only lvalue elements\ninside the loops.)  You can see the correct behaviour by replacing the 1..5 with 1, 2, 3, 4,\n5.\n\nmodperl 1.26 Doesn't Build With Threaded Perl\nUse modperl 1.27 or higher.\n"
                },
                {
                    "name": "lib/ftmp-security tests warn 'system possibly insecure'",
                    "content": "Don't panic.  Read the 'make test' section of INSTALL instead.\n"
                },
                {
                    "name": "libwww-perl (LWP) fails base/date #51",
                    "content": "Use libwww-perl 5.65 or later.\n"
                },
                {
                    "name": "PDL failing some tests",
                    "content": "Use PDL 2.3.4 or later.\n\nPerlgetsv\nYou may get errors like 'Undefined symbol \"Perlgetsv\"' or \"can't resolve symbol\n'Perlgetsv'\", or the symbol may be \"Perlsv2pv\".  This probably means that you are trying\nto use an older shared Perl library (or extensions linked with such) with Perl 5.8.0\nexecutable.  Perl used to have such a subroutine, but that is no more the case.  Check your\nshared library path, and any shared Perl libraries in those directories.\n\nSometimes this problem may also indicate a partial Perl 5.8.0 installation, see \"Mac OS X\ndyld undefined symbols\" for an example and how to deal with it.\n"
                },
                {
                    "name": "Self-tying Problems",
                    "content": "Self-tying of arrays and hashes is broken in rather deep and hard-to-fix ways.  As a stop-gap\nmeasure to avoid people from getting frustrated at the mysterious results (core dumps, most\noften), it is forbidden for now (you will get a fatal error even from an attempt).\n\nA change to self-tying of globs has caused them to be recursively referenced (see: \"Two-\nPhased Garbage Collection\" in perlobj).  You will now need an explicit untie to destroy a\nself-tied glob.  This behaviour may be fixed at a later date.\n\nSelf-tying of scalars and IO thingies works.\n"
                },
                {
                    "name": "ext/threads/t/libc",
                    "content": "If this test fails, it indicates that your libc (C library) is not threadsafe.  This\nparticular test stress tests the localtime() call to find out whether it is threadsafe.  See\nperlthrtut for more information.\n"
                },
                {
                    "name": "Failure of Thread (5.005-style) tests",
                    "content": ""
                },
                {
                    "name": "Note that support for 5.005-style threading is deprecated, experimental and practically",
                    "content": ""
                },
                {
                    "name": "unsupported.  In 5.10, it is expected to be removed.  You should migrate your code to",
                    "content": ""
                },
                {
                    "name": "ithreads.",
                    "content": "The following tests are known to fail due to fundamental problems in the 5.005 threading\nimplementation. These are not new failures--Perl 5.0050x has the same bugs, but didn't have\nthese tests.\n\n../ext/B/t/xref.t                    255 65280    14   12  85.71%  3-14\n../ext/List/Util/t/first.t           255 65280     7    4  57.14%  2 5-7\n../lib/English.t                       2   512    54    2   3.70%  2-3\n../lib/FileCache.t                                 5    1  20.00%  5\n../lib/Filter/Simple/t/data.t                      6    3  50.00%  1-3\n../lib/Filter/Simple/t/filteronly.                9    3  33.33%  1-2 5\n../lib/Math/BigInt/t/barembf.t                 1627    4   0.25%  8 11 1626-1627\n../lib/Math/BigInt/t/bigfltpm.t                 1629    4   0.25%  10 13 1628-\n1629\n../lib/Math/BigInt/t/submbf.t                  1633    4   0.24%  8 11 1632-1633\n../lib/Math/BigInt/t/withsub.t                 1628    4   0.25%  9 12 1627-1628\n../lib/Tie/File/t/31autodefer.t     255 65280    65   32  49.23%  34-65\n../lib/autouse.t                                  10    1  10.00%  4\nop/flip.t                                         15    1   6.67%  15\n\nThese failures are unlikely to get fixed as 5.005-style threads are considered fundamentally\nbroken.  (Basically what happens is that competing threads can corrupt shared global state,\none good example being regular expression engine's state.)\n"
                },
                {
                    "name": "Timing problems",
                    "content": "The following tests may fail intermittently because of timing problems, for example if the\nsystem is heavily loaded.\n\nt/op/alarm.t\next/Time/HiRes/HiRes.t\nlib/Benchmark.t\nlib/Memoize/t/expmodt.t\nlib/Memoize/t/speed.t\n\nIn case of failure please try running them manually, for example\n\n./perl -Ilib ext/Time/HiRes/HiRes.t\n"
                },
                {
                    "name": "Tied/Magical Array/Hash Elements Do Not Autovivify",
                    "content": "For normal arrays \"$foo = \\$bar[1]\" will assign \"undef\" to $bar[1] (assuming that it didn't\nexist before), but for tied/magical arrays and hashes such autovivification does not happen\nbecause there is currently no way to catch the reference creation.  The same problem affects\nslicing over non-existent indices/keys of a tied/magical array/hash.\n"
                },
                {
                    "name": "Unicode in package/class and subroutine names does not work",
                    "content": "One can have Unicode in identifier names, but not in package/class or subroutine names.\nWhile some limited functionality towards this does exist as of Perl 5.8.0, that is more\naccidental than designed; use of Unicode for the said purposes is unsupported.\n\nOne reason of this unfinishedness is its (currently) inherent unportability: since both\npackage names and subroutine names may need to be mapped to file and directory names, the\nUnicode capability of the filesystem becomes important-- and there unfortunately aren't\nportable answers.\n"
                },
                {
                    "name": "Platform Specific Problems",
                    "content": "AIX\n•   If using the AIX native make command, instead of just \"make\" issue \"make all\".  In some\nsetups the former has been known to spuriously also try to run \"make install\".\nAlternatively, you may want to use GNU make.\n\n•   In AIX 4.2, Perl extensions that use C++ functions that use statics may have problems in\nthat the statics are not getting initialized.  In newer AIX releases, this has been\nsolved by linking Perl with the libCr library, but unfortunately in AIX 4.2 the said\nlibrary has an obscure bug where the various functions related to time (such as time()\nand gettimeofday()) return broken values, and therefore in AIX 4.2 Perl is not linked\nagainst libCr.\n\n•   vac 5.0.0.0 May Produce Buggy Code For Perl\n\nThe AIX C compiler vac version 5.0.0.0 may produce buggy code, resulting in a few random\ntests failing when run as part of \"make test\", but when the failing tests are run by\nhand, they succeed.  We suggest upgrading to at least vac version 5.0.1.0, that has been\nknown to compile Perl correctly.  \"lslpp -L|grep vac.C\" will tell you the vac version.\nSee README.aix.\n\n•   If building threaded Perl, you may get compilation warning from ppsys.c:\n\n\"ppsys.c\", line 4651.39: 1506-280 (W) Function argument assignment between types \"unsigned char*\" and \"const void*\" is not allowed.\n\nThis is harmless; it is caused by the getnetbyaddr() and getnetbyaddrr() having slightly\ndifferent types for their first argument.\n"
                },
                {
                    "name": "Alpha systems with old gccs fail several tests",
                    "content": "If you see op/pack, op/pat, op/regexp, or ext/Storable tests failing in a Linux/alpha or\n*BSD/Alpha, it's probably time to upgrade your gcc.  gccs prior to 2.95.3 are definitely not\ngood enough, and gcc 3.1 may be even better.  (RedHat Linux/alpha with gcc 3.1 reported no\nproblems, as did Linux 2.4.18 with gcc 2.95.4.)  (In Tru64, it is preferable to use the\nbundled C compiler.)\n"
                },
                {
                    "name": "AmigaOS",
                    "content": "Perl 5.8.0 doesn't build in AmigaOS.  It broke at some point during the ithreads work and we\ncould not find Amiga experts to unbreak the problems.  Perl 5.6.1 still works for AmigaOS (as\ndoes the 5.7.2 development release).\n"
                },
                {
                    "name": "BeOS",
                    "content": "The following tests fail on 5.8.0 Perl in BeOS Personal 5.03:\n\nt/op/lfs............................FAILED at test 17\nt/op/magic..........................FAILED at test 24\next/Fcntl/t/syslfs..................FAILED at test 17\next/File/Glob/t/basic...............FAILED at test 3\next/POSIX/t/sigaction...............FAILED at test 13\next/POSIX/t/waitpid.................FAILED at test 1\n\n(Note: more information was available in README.beos until support for BeOS was removed in\nPerl v5.18.0)\n"
                },
                {
                    "name": "Cygwin \"unable to remap\"",
                    "content": "For example when building the Tk extension for Cygwin, you may get an error message saying\n\"unable to remap\".  This is known problem with Cygwin, and a workaround is detailed in here:\nhttp://sources.redhat.com/ml/cygwin/2001-12/msg00894.html\n"
                },
                {
                    "name": "Cygwin ndbm tests fail on FAT",
                    "content": "One can build but not install (or test the build of) the NDBMFile on FAT filesystems.\nInstallation (or build) on NTFS works fine.  If one attempts the test on a FAT install (or\nbuild) the following failures are expected:\n\n../ext/NDBMFile/ndbm.t       13  3328    71   59  83.10%  1-2 4 16-71\n../ext/ODBMFile/odbm.t      255 65280    ??   ??       %  ??\n../lib/AnyDBMFile.t           2   512    12    2  16.67%  1 4\n../lib/Memoize/t/errors.t      0   139    11    5  45.45%  7-11\n../lib/Memoize/t/tiendbm.t   13  3328     4    4 100.00%  1-4\nrun/freshperl.t                          97    1   1.03%  91\n\nNDBMFile fails and ODBMFile just coredumps.\n\nIf you intend to run only on FAT (or if using AnyDBMFile on FAT), run Configure with the\n-Uindbm and -Uidbm options to prevent NDBMFile and ODBMFile being built.\n"
                },
                {
                    "name": "DJGPP Failures",
                    "content": "t/op/stat............................FAILED at test 29\nlib/File/Find/t/find.................FAILED at test 1\nlib/File/Find/t/taint................FAILED at test 1\nlib/h2xs.............................FAILED at test 15\nlib/Pod/t/eol........................FAILED at test 1\nlib/Test/Harness/t/strap-analyze.....FAILED at test 8\nlib/Test/Harness/t/test-harness......FAILED at test 23\nlib/Test/Simple/t/exit...............FAILED at test 1\n\nThe above failures are known as of 5.8.0 with native builds with long filenames, but there\nare a few more if running under dosemu because of limitations (and maybe bugs) of dosemu:\n\nt/comp/cpp...........................FAILED at test 3\nt/op/inccode.........................(crash)\n\nand a few lib/ExtUtils tests, and several hundred Encode/t/Aliases.t failures that work fine\nwith long filenames.  So you really might prefer native builds and long filenames.\n"
                },
                {
                    "name": "FreeBSD built with ithreads coredumps reading large directories",
                    "content": "This is a known bug in FreeBSD 4.5's readdirr(), it has been fixed in FreeBSD 4.6 (see\nperlfreebsd (README.freebsd)).\n"
                },
                {
                    "name": "FreeBSD Failing locale Test 117 For ISO 8859-15 Locales",
                    "content": "The ISO 8859-15 locales may fail the locale test 117 in FreeBSD.  This is caused by the\ncharacters \\xFF (y with diaeresis) and \\xBE (Y with diaeresis) not behaving correctly when\nbeing matched case-insensitively.  Apparently this problem has been fixed in the latest\nFreeBSD releases.  ( http://www.freebsd.org/cgi/query-pr.cgi?pr=34308 )\n"
                },
                {
                    "name": "IRIX fails ext/List/Util/t/shuffle.t or Digest::MD5",
                    "content": "IRIX with MIPSpro 7.3.1.2m or 7.3.1.3m compiler may fail the List::Util test\next/List/Util/t/shuffle.t by dumping core.  This seems to be a compiler error since if\ncompiled with gcc no core dump ensues, and no failures have been seen on the said test on any\nother platform.\n\nSimilarly, building the Digest::MD5 extension has been known to fail with \"* Termination\ncode 139 (bu21)\".\n\nThe cure is to drop optimization level (Configure -Doptimize=-O2).\n"
                },
                {
                    "name": "HP-UX lib/posix Subtest 9 Fails When LP64-Configured",
                    "content": "If perl is configured with -Duse64bitall, the successful result of the subtest 10 of\nlib/posix may arrive before the successful result of the subtest 9, which confuses the test\nharness so much that it thinks the subtest 9 failed.\n"
                },
                {
                    "name": "Linux with glibc 2.2.5 fails t/op/int subtest #6 with -Duse64bitint",
                    "content": "This is a known bug in the glibc 2.2.5 with long long integers.  (\nhttp://bugzilla.redhat.com/bugzilla/showbug.cgi?id=65612 )\n"
                },
                {
                    "name": "Linux With Sfio Fails op/misc Test 48",
                    "content": "No known fix.\n"
                },
                {
                    "name": "Mac OS X",
                    "content": "Please remember to set your environment variable LCALL to \"C\" (setenv LCALL C) before\nrunning \"make test\" to avoid a lot of warnings about the broken locales of Mac OS X.\n\nThe following tests are known to fail in Mac OS X 10.1.5 because of buggy (old)\nimplementations of Berkeley DB included in Mac OS X:\n\nFailed Test                 Stat Wstat Total Fail  Failed  List of Failed\n-------------------------------------------------------------------------\n../ext/DBFile/t/db-btree.t    0    11    ??   ??       %  ??\n../ext/DBFile/t/db-recno.t              149    3   2.01%  61 63 65\n\nIf you are building on a UFS partition, you will also probably see t/op/stat.t subtest #9\nfail.  This is caused by Darwin's UFS not supporting inode change time.\n\nAlso the ext/POSIX/t/posix.t subtest #10 fails but it is skipped for now because the failure\nis Apple's fault, not Perl's (blocked signals are lost).\n\nIf you Configure with ithreads, ext/threads/t/libc.t will fail. Again, this is not Perl's\nfault-- the libc of Mac OS X is not threadsafe (in this particular test, the localtime() call\nis found to be threadunsafe.)\n"
                },
                {
                    "name": "Mac OS X dyld undefined symbols",
                    "content": "If after installing Perl 5.8.0 you are getting warnings about missing symbols, for example\n\ndyld: perl Undefined symbols\nperlsv2pv\nperlgetsv\n\nyou probably have an old pre-Perl-5.8.0 installation (or parts of one) in /Library/Perl (the\nundefined symbols used to exist in pre-5.8.0 Perls).  It seems that for some reason \"make\ninstall\" doesn't always completely overwrite the files in /Library/Perl.  You can move the\nold Perl shared library out of the way like this:\n\ncd /Library/Perl/darwin/CORE\nmv libperl.dylib libperlold.dylib\n\nand then reissue \"make install\".  Note that the above of course is extremely disruptive for\nanything using the /usr/local/bin/perl.  If that doesn't help, you may have to try removing\nall the .bundle files from beneath /Library/Perl, and again \"make install\"-ing.\n"
                },
                {
                    "name": "OS/2 Test Failures",
                    "content": "The following tests are known to fail on OS/2 (for clarity only the failures are shown, not\nthe full error messages):\n\n../lib/ExtUtils/t/Mkbootstrap.t    1   256    18    1   5.56%  8\n../lib/ExtUtils/t/Packlist.t       1   256    34    1   2.94%  17\n../lib/ExtUtils/t/basic.t          1   256    17    1   5.88%  14\nlib/os2process.t                  2   512   227    2   0.88%  174 209\nlib/os2processkid.t                        227    2   0.88%  174 209\nlib/rxcmprt.t                   255 65280    18    3  16.67%  16-18\n"
                },
                {
                    "name": "op/sprintf tests 91, 129, and 130",
                    "content": "The op/sprintf tests 91, 129, and 130 are known to fail on some platforms.  Examples include\nany platform using sfio, and Compaq/Tandem's NonStop-UX.\n\nTest 91 is known to fail on QNX6 (nto), because \"sprintf '%e',0\" incorrectly produces\n0.000000e+0 instead of 0.000000e+00.\n\nFor tests 129 and 130, the failing platforms do not comply with the ANSI C Standard: lines\n19ff on page 134 of ANSI X3.159 1989, to be exact.  (They produce something other than \"1\"\nand \"-1\" when formatting 0.6 and -0.6 using the printf format \"%.0f\"; most often, they\nproduce \"0\" and \"-0\".)\n\nSCO\nThe socketpair tests are known to be unhappy in SCO 3.2v5.0.4:\n\next/Socket/socketpair.t...............FAILED tests 15-45\n"
                },
                {
                    "name": "Solaris 2.5",
                    "content": "In case you are still using Solaris 2.5 (aka SunOS 5.5), you may experience failures (the\ntest core dumping) in lib/locale.t.  The suggested cure is to upgrade your Solaris.\n"
                },
                {
                    "name": "Solaris x86 Fails Tests With -Duse64bitint",
                    "content": "The following tests are known to fail in Solaris x86 with Perl configured to use 64 bit\nintegers:\n\next/Data/Dumper/t/dumper.............FAILED at test 268\next/Devel/Peek/Peek..................FAILED at test 7\n"
                },
                {
                    "name": "SUPER-UX (NEC SX)",
                    "content": "The following tests are known to fail on SUPER-UX:\n\nop/64bitint...........................FAILED tests 29-30, 32-33, 35-36\nop/arith..............................FAILED tests 128-130\nop/pack...............................FAILED tests 25-5625\nop/pow................................\nop/taint..............................# msgsnd failed\n../ext/IO/lib/IO/t/iopoll............FAILED tests 3-4\n../ext/IPC/SysV/ipcsysv...............FAILED tests 2, 5-6\n../ext/IPC/SysV/t/msg.................FAILED tests 2, 4-6\n../ext/Socket/socketpair..............FAILED tests 12\n../lib/IPC/SysV.......................FAILED tests 2, 5-6\n../lib/warnings.......................FAILED tests 115-116, 118-119\n\nThe op/pack failure (\"Cannot compress negative numbers at op/pack.t line 126\") is serious but\nas of yet unsolved.  It points at some problems with the signedness handling of the C\ncompiler, as do the 64bitint, arith, and pow failures.  Most of the rest point at problems\nwith SysV IPC.\n"
                },
                {
                    "name": "Term::ReadKey not working on Win32",
                    "content": "Use Term::ReadKey 2.20 or later.\n"
                },
                {
                    "name": "UNICOS/mk",
                    "content": "•   During Configure, the test\n\nGuessing which symbols your C compiler and preprocessor define...\n\nwill probably fail with error messages like\n\nCC-20 cc: ERROR File = try.c, Line = 3\nThe identifier \"bad\" is undefined.\n\nbad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K\n^\n\nCC-65 cc: ERROR File = try.c, Line = 3\nA semicolon is expected at this point.\n\nThis is caused by a bug in the awk utility of UNICOS/mk.  You can ignore the error, but\nit does cause a slight problem: you cannot fully benefit from the h2ph utility (see h2ph)\nthat can be used to convert C headers to Perl libraries, mainly used to be able to access\nfrom Perl the constants defined using C preprocessor, cpp.  Because of the above error,\nparts of the converted headers will be invisible.  Luckily, these days the need for h2ph\nis rare.\n\n•   If building Perl with interpreter threads (ithreads), the getgrent(), getgrnam(), and\ngetgrgid() functions cannot return the list of the group members due to a bug in the\nmultithreaded support of UNICOS/mk.  What this means is that in list context the\nfunctions will return only three values, not four.\n\nUTS\nThere are a few known test failures.  (Note: the relevant information was available in\nREADME.uts until support for UTS was removed in Perl v5.18.0)\n"
                },
                {
                    "name": "VOS (Stratus)",
                    "content": "When Perl is built using the native build process on VOS Release 14.5.0 and GNU C++/GNU Tools\n2.0.1, all attempted tests either pass or result in TODO (ignored) failures.\n\nVMS\nThere should be no reported test failures with a default configuration, though there are a\nnumber of tests marked TODO that point to areas needing further debugging and/or porting\nwork.\n"
                },
                {
                    "name": "Win32",
                    "content": "In multi-CPU boxes, there are some problems with the I/O buffering: some output may appear\ntwice.\n"
                },
                {
                    "name": "XML::Parser not working",
                    "content": "Use XML::Parser 2.31 or later.\n"
                },
                {
                    "name": "z/OS (OS/390)",
                    "content": "z/OS has rather many test failures but the situation is actually much better than it was in\n5.6.0; it's just that so many new modules and tests have been added.\n\nFailed Test                   Stat Wstat Total Fail  Failed  List of Failed\n---------------------------------------------------------------------------\n../ext/Data/Dumper/t/dumper.t              357    8   2.24%  311 314 325 327\n331 333 337 339\n../ext/IO/lib/IO/t/iounix.t                 5    4  80.00%  2-5\n../ext/Storable/t/downgrade.t   12  3072   169   12   7.10%  14-15 46-47 78-79\n110-111 150 161\n../lib/ExtUtils/t/Constant.t   121 30976    48   48 100.00%  1-48\n../lib/ExtUtils/t/Embed.t                    9    9 100.00%  1-9\nop/pat.t                                   922    7   0.76%  665 776 785 832-\n834 845\nop/sprintf.t                               224    3   1.34%  98 100 136\nop/tr.t                                     97    5   5.15%  63 71-74\nuni/fold.t                                 780    6   0.77%  61 169 196 661\n710-711\n\nThe failures in dumper.t and downgrade.t are problems in the tests, those in iounix and\nsprintf are problems in the USS (UDP sockets and printf formats).  The pat, tr, and fold\nfailures are genuine Perl problems caused by EBCDIC (and in the pat and fold cases, combining\nthat with Unicode).  The Constant and Embed are probably problems in the tests (since they\ntest Perl's ability to build extensions, and that seems to be working reasonably well.)\n"
                },
                {
                    "name": "Unicode Support on EBCDIC Still Spotty",
                    "content": "Though mostly working, Unicode support still has problem spots on EBCDIC platforms.  One such\nknown spot are the \"\\p{}\" and \"\\P{}\" regular expression constructs for code points less than\n256: the \"pP\" are testing for Unicode code points, not knowing about EBCDIC.\n"
                },
                {
                    "name": "Seen In Perl 5.7 But Gone Now",
                    "content": "\"Time::Piece\" (previously known as \"Time::Object\") was removed because it was felt that it\ndidn't have enough value in it to be a core module.  It is still a useful module, though, and\nis available from the CPAN.\n\nPerl 5.8 unfortunately does not build anymore on AmigaOS; this broke accidentally at some\npoint.  Since there are not that many Amiga developers available, we could not get this fixed\nand tested in time for 5.8.0.  Perl 5.6.1 still works for AmigaOS (as does the 5.7.2\ndevelopment release).\n\nThe \"PerlIO::Scalar\" and \"PerlIO::Via\" (capitalised) were renamed as \"PerlIO::scalar\" and\n\"PerlIO::via\" (all lowercase) just before 5.8.0.  The main rationale was to have all core\nPerlIO layers to have all lowercase names.  The \"plugins\" are named as usual, for example\n\"PerlIO::via::QuotedPrint\".\n\nThe \"threads::shared::queue\" and \"threads::shared::semaphore\" were renamed as \"Thread::Queue\"\nand \"Thread::Semaphore\" just before 5.8.0.  The main rationale was to have thread modules to\nobey normal naming, \"Thread::\" (the \"threads\" and \"threads::shared\" themselves are more\npragma-like, they affect compile-time, so they stay lowercase).\n"
                },
                {
                    "name": "Reporting Bugs",
                    "content": "If you find what you think is a bug, you might check the articles recently posted to the\ncomp.lang.perl.misc newsgroup and the perl bug database at http://bugs.perl.org/ .  There may\nalso be information at http://www.perl.com/ , the Perl Home Page.\n\nIf you believe you have an unreported bug, please run the perlbug program included with your\nrelease.  Be sure to trim your bug down to a tiny but sufficient test case.  Your bug report,\nalong with the output of \"perl -V\", will be sent off to perlbug@perl.org to be analysed by\nthe Perl porting team.\n"
                }
            ]
        },
        "SEE ALSO": {
            "content": "The Changes file for exhaustive details on what changed.\n\nThe INSTALL file for how to build Perl.\n\nThe README file for general stuff.\n\nThe Artistic and Copying files for copyright information.\n",
            "subsections": []
        },
        "HISTORY": {
            "content": "Written by Jarkko Hietaniemi <jhi@iki.fi>.\n\n\n\nperl v5.34.0                                 2026-06-23                               PERL58DELTA(1)",
            "subsections": []
        }
    },
    "summary": "perl58delta - what is new for perl v5.8.0",
    "flags": [],
    "examples": [],
    "see_also": []
}