{
    "mode": "perldoc",
    "parameter": "Cpanel::JSON::XS",
    "section": "",
    "url": "https://www.chedong.com/phpMan.php/perldoc/Cpanel%3A%3AJSON%3A%3AXS/json",
    "generated": "2026-06-13T04:42:39Z",
    "synopsis": "use Cpanel::JSON::XS;\n# exported functions, they croak on error\n# and expect/generate UTF-8\n$utf8encodedjsontext = encodejson $perlhashorarrayref;\n$perlhashorarrayref  = decodejson $utf8encodedjsontext;\n# OO-interface\n$coder = Cpanel::JSON::XS->new->ascii->pretty->allownonref;\n$prettyprintedunencoded = $coder->encode ($perlscalar);\n$perlscalar = $coder->decode ($unicodejsontext);\n# Note that 5.6 misses most smart utf8 and encoding functionalities\n# of newer releases.\n# Note that L<JSON::MaybeXS> will automatically use Cpanel::JSON::XS\n# if available, at virtually no speed overhead either, so you should\n# be able to just:\nuse JSON::MaybeXS;\n# and do the same things, except that you have a pure-perl fallback now.\nNote that this module will be replaced by a new JSON::Safe module soon,\nwith the same API just guaranteed safe defaults.",
    "sections": {
        "NAME": {
            "content": "Cpanel::JSON::XS - cPanel fork of JSON::XS, fast and correct serializing\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "use Cpanel::JSON::XS;\n\n# exported functions, they croak on error\n# and expect/generate UTF-8\n\n$utf8encodedjsontext = encodejson $perlhashorarrayref;\n$perlhashorarrayref  = decodejson $utf8encodedjsontext;\n\n# OO-interface\n\n$coder = Cpanel::JSON::XS->new->ascii->pretty->allownonref;\n$prettyprintedunencoded = $coder->encode ($perlscalar);\n$perlscalar = $coder->decode ($unicodejsontext);\n\n# Note that 5.6 misses most smart utf8 and encoding functionalities\n# of newer releases.\n\n# Note that L<JSON::MaybeXS> will automatically use Cpanel::JSON::XS\n# if available, at virtually no speed overhead either, so you should\n# be able to just:\n\nuse JSON::MaybeXS;\n\n# and do the same things, except that you have a pure-perl fallback now.\n\nNote that this module will be replaced by a new JSON::Safe module soon,\nwith the same API just guaranteed safe defaults.\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "This module converts Perl data structures to JSON and vice versa. Its primary goal is to be\n*correct* and its secondary goal is to be *fast*. To reach the latter goal it was written in C.\n\nAs this is the n-th-something JSON module on CPAN, what was the reason to write yet another JSON\nmodule? While it seems there are many JSON modules, none of them correctly handle all corner\ncases, and in most cases their maintainers are unresponsive, gone missing, or not listening to\nbug reports for other reasons.\n\nSee below for the cPanel fork.\n\nSee MAPPING, below, on how Cpanel::JSON::XS maps perl values to JSON values and vice versa.\n\nFEATURES\n*   correct Unicode handling\n\nThis module knows how to handle Unicode with Perl version higher than 5.8.5, documents how\nand when it does so, and even documents what \"correct\" means.\n\n*   round-trip integrity\n\nWhen you serialize a perl data structure using only data types supported by JSON and Perl,\nthe deserialized data structure is identical on the Perl level. (e.g. the string \"2.0\"\ndoesn't suddenly become \"2\" just because it looks like a number). There *are* minor\nexceptions to this, read the MAPPING section below to learn about those.\n\n*   strict checking of JSON correctness\n\nThere is no guessing, no generating of illegal JSON texts by default, and only JSON is\naccepted as input by default. the latter is a security feature.\n\n*   fast\n\nCompared to other JSON modules and other serializers such as Storable, this module usually\ncompares favourably in terms of speed, too.\n\n*   simple to use\n\nThis module has both a simple functional interface as well as an object oriented interface.\n\n*   reasonably versatile output formats\n\nYou can choose between the most compact guaranteed-single-line format possible (nice for\nsimple line-based protocols), a pure-ASCII format (for when your transport is not 8-bit\nclean, still supports the whole Unicode range), or a pretty-printed format (for when you\nwant to read that stuff). Or you can combine those features in whatever way you like.\n\ncPanel fork\nSince the original author MLEHMANN has no public bugtracker, this cPanel fork sits now on\ngithub.\n\nsrc repo: <https://github.com/rurban/Cpanel-JSON-XS> original: <http://cvs.schmorp.de/JSON-XS/>\n\nRT: <https://github.com/rurban/Cpanel-JSON-XS/issues> or\n<https://rt.cpan.org/Public/Dist/Display.html?Queue=Cpanel-JSON-XS>\n\nChanges to JSON::XS\n\n- stricter decodejson() as documented. non-refs are disallowed. added a 2nd optional argument.",
            "subsections": [
                {
                    "name": "decode",
                    "content": "- fixed encode of numbers for dual-vars. Different string representations are preserved, but\nnumbers with temporary strings which represent the same number are here treated as numbers, not\nstrings. Cpanel::JSON::XS is a bit slower, but preserves numeric types better.\n\n- numbers ending with .0 stray numbers, are not converted to integers. [#63] dual-vars which are\nrepresented as number not integer (42+\"bar\" != 5.8.9) are now encoded as number (=> 42.0)\nbecause internally it's now a NOK type. However !!1 which is wrongly encoded in 5.8 as \"1\"/1.0\nis still represented as integer.\n\n- different handling of inf/nan. Default now to null, optionally with stringifyinfnan() to\n\"inf\"/\"nan\". [#28, #32]\n\n- added \"binary\" extension, non-JSON and non JSON parsable, allows \"\\xNN\" and \"\\NNN\" sequences.\n\n- 5.6.2 support; sacrificing some utf8 features (assuming bytes all-over), no multi-byte unicode\ncharacters with 5.6.\n\n- interop for true/false overloading. JSON::XS, JSON::PP and Mojo::JSON representations for\nbooleans are accepted and JSON::XS accepts Cpanel::JSON::XS booleans [#13, #37] Fixed\noverloading of booleans. Cpanel::JSON::XS::true stringifies again to \"1\", not \"true\", analog to\nall other JSON modules.\n\n- native boolean mapping of yes and no to true and false, as in YAML::XS. In perl \"!0\" is yes,\n\"!1\" is no. The JSON value true maps to 1, false maps to 0. [#39]\n\n- support arbitrary stringification with encode, with convertblessed and allowblessed.\n\n- ithread support. Cpanel::JSON::XS is thread-safe, JSON::XS not\n\n- isbool can be called as method, JSON::XS::isbool not.\n\n- performance optimizations for threaded Perls\n\n- relaxed mode, allowing many popular extensions\n\n- additional fixes for:\n\n- [cpan #88061] AIX atof without USELONGDOUBLE\n\n- #10 unsharehek crash\n\n- #7, #29 avoid re-blessing where possible. It fails in JSON::XS for\nREADONLY values, i.e. restricted hashes.\n\n- #41 overloading of booleans, use the object not the reference.\n\n- #62 -Dusequadmath conversion and no SEGV.\n\n- #72 parsing of values followed \\0, like 1\\0 does fail.\n\n- #72 parsing of illegal unicode or non-unicode characters.\n\n- #96 locale-insensitive numeric conversion.\n\n- #154 numeric conversion fixed since 5.22, using the same strtold as perl5.\n\n- #167 sort tied hashes with canonical.\n\n- public maintenance and bugtracker\n\n- use ppport.h, sanify XS.xs comment styles, harness C coding style\n\n- common::sense is optional. When available it is not used in the published production module,\njust during development and testing.\n\n- extended testsuite, passes all http://seriot.ch/parsingjson.html tests. In fact it is the\nonly know JSON decoder which does so, while also being the fastest.\n\n- support many more options and methods from JSON::PP: stringifyinfnan, allowunknown,\nallowstringify, allowbarekey, encodestringify, allowbignum, allowsinglequote, sortby\n(partially), escapeslash, convertblessed, ... optional decodejson(, allownonref) arg.\nrelaxed implements allowdupkeys.\n\n- support all 5 unicode BOM's: UTF-8, UTF-16LE, UTF-16BE, UTF-32LE, UTF-32BE, encoding\ninternally to UTF-8.\n"
                }
            ]
        },
        "FUNCTIONAL INTERFACE": {
            "content": "The following convenience methods are provided by this module. They are exported by default:\n\n$jsontext = encodejson $perlscalar, [jsontype]\nConverts the given Perl data structure to a UTF-8 encoded, binary string (that is, the\nstring contains octets only). Croaks on error.\n\nThis function call is functionally identical to:\n\n$jsontext = Cpanel::JSON::XS->new->utf8->encode ($perlscalar, $jsontype)\n\nExcept being faster.\n\nFor the type argument see Cpanel::JSON::XS::Type.\n\n$perlscalar = decodejson $jsontext [, $allownonref [, my $jsontype ] ]\nThe opposite of \"encodejson\": expects an UTF-8 (binary) string of an json reference and\ntries to parse that as an UTF-8 encoded JSON text, returning the resulting reference. Croaks\non error.\n\nThis function call is functionally identical to:\n\n$perlscalar = Cpanel::JSON::XS->new->utf8->decode ($jsontext, $jsontype)\n\nexcept being faster.\n\nNote that older decodejson versions in Cpanel::JSON::XS older than 3.0116 and JSON::XS did\nnot set allownonref but allowed them due to a bug in the decoder.\n\nIf the new 2nd optional $allownonref argument is set and not false, the \"allownonref\"\noption will be set and the function will act is described as in the relaxed RFC 7159\nallowing all values such as objects, arrays, strings, numbers, \"null\", \"true\", and \"false\".\nSee \"\"OLD\" VS. \"NEW\" JSON (RFC 4627 VS. RFC 7159)\" below, why you don't want to do that.\n\nFor the 3rd optional type argument see Cpanel::JSON::XS::Type.\n\n$isboolean = Cpanel::JSON::XS::isbool $scalar\nReturns true if the passed scalar represents either \"JSON::PP::true\" or \"JSON::PP::false\",\ntwo constants that act like 1 and 0, respectively and are used to represent JSON \"true\" and\n\"false\" values in Perl. (Also recognizes the booleans produced by JSON::XS.)\n\nSee MAPPING, below, for more information on how JSON values are mapped to Perl.\n",
            "subsections": []
        },
        "DEPRECATED FUNCTIONS": {
            "content": "fromjson\nfromjson has been renamed to decodejson\n\ntojson\ntojson has been renamed to encodejson\n",
            "subsections": []
        },
        "A FEW NOTES ON UNICODE AND PERL": {
            "content": "Since this often leads to confusion, here are a few very clear words on how Unicode works in\nPerl, modulo bugs.\n\n1. Perl strings can store characters with ordinal values > 255.\nThis enables you to store Unicode characters as single characters in a Perl string - very\nnatural.\n\n2. Perl does *not* associate an encoding with your strings.\n... until you force it to, e.g. when matching it against a regex, or printing the scalar to\na file, in which case Perl either interprets your string as locale-encoded text,\noctets/binary, or as Unicode, depending on various settings. In no case is an encoding\nstored together with your data, it is *use* that decides encoding, not any magical meta\ndata.\n\n3. The internal utf-8 flag has no meaning with regards to the encoding of your string.\n4. A \"Unicode String\" is simply a string where each character can be validly interpreted as a\nUnicode code point.\nIf you have UTF-8 encoded data, it is no longer a Unicode string, but a Unicode string\nencoded in UTF-8, giving you a binary string.\n\n5. A string containing \"high\" (> 255) character values is *not* a UTF-8 string.\n6. Unicode noncharacters only warn, as in core.\nThe 66 Unicode noncharacters U+FDD0..U+FDEF, and U+*FFFE, U+*FFFF just warn, see\n<http://www.unicode.org/versions/corrigendum9.html>. But illegal surrogate pairs fail to\nparse.\n\n7. Raw non-Unicode characters above U+10FFFF are disallowed.\nRaw non-Unicode characters outside the valid unicode range fail to parse, because \"A string\nis a sequence of zero or more Unicode characters\" RFC 7159 section 1 and \"JSON text SHALL be\nencoded in Unicode RFC 7159 section 8.1. We use now the UTF8DISALLOWSUPER flag when\nparsing unicode.\n\nI hope this helps :)\n",
            "subsections": []
        },
        "OBJECT-ORIENTED INTERFACE": {
            "content": "The object oriented interface lets you configure your own encoding or decoding style, within the\nlimits of supported formats.\n\n$json = new Cpanel::JSON::XS\nCreates a new JSON object that can be used to de/encode JSON strings. All boolean flags\ndescribed below are by default *disabled*.\n\nThe mutators for flags all return the JSON object again and thus calls can be chained:\n\nmy $json = Cpanel::JSON::XS->new->utf8->spaceafter->encode ({a => [1,2]})\n=> {\"a\": [1, 2]}\n\n$json = $json->ascii ([$enable])\n$enabled = $json->getascii\nIf $enable is true (or missing), then the \"encode\" method will not generate characters\noutside the code range 0..127 (which is ASCII). Any Unicode characters outside that range\nwill be escaped using either a single \"\\uXXXX\" (BMP characters) or a double \"\\uHHHH\\uLLLLL\"\nescape sequence, as per RFC4627. The resulting encoded JSON text can be treated as a native\nUnicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string, or any other\nsuperset of ASCII.\n\nIf $enable is false, then the \"encode\" method will not escape Unicode characters unless\nrequired by the JSON syntax or other flags. This results in a faster and more compact\nformat.\n\nSee also the section *ENCODING/CODESET FLAG NOTES* later in this document.\n\nThe main use for this flag is to produce JSON texts that can be transmitted over a 7-bit\nchannel, as the encoded JSON texts will not contain any 8 bit characters.\n\nCpanel::JSON::XS->new->ascii (1)->encode ([chr 0x10401])\n=> [\"\\ud801\\udc01\"]\n\n$json = $json->latin1 ([$enable])\n$enabled = $json->getlatin1\nIf $enable is true (or missing), then the \"encode\" method will encode the resulting JSON\ntext as latin1 (or ISO-8859-1), escaping any characters outside the code range 0..255. The\nresulting string can be treated as a latin1-encoded JSON text or a native Unicode string.\nThe \"decode\" method will not be affected in any way by this flag, as \"decode\" by default\nexpects Unicode, which is a strict superset of latin1.\n\nIf $enable is false, then the \"encode\" method will not escape Unicode characters unless\nrequired by the JSON syntax or other flags.\n\nSee also the section *ENCODING/CODESET FLAG NOTES* later in this document.\n\nThe main use for this flag is efficiently encoding binary data as JSON text, as most octets\nwill not be escaped, resulting in a smaller encoded size. The disadvantage is that the\nresulting JSON text is encoded in latin1 (and must correctly be treated as such when storing\nand transferring), a rare encoding for JSON. It is therefore most useful when you want to\nstore data structures known to contain binary data efficiently in files or databases, not\nwhen talking to other JSON encoders/decoders.\n\nCpanel::JSON::XS->new->latin1->encode ([\"\\x{89}\\x{abc}\"]\n=> [\"\\x{89}\\\\u0abc\"]    # (perl syntax, U+abc escaped, U+89 not)\n\n$json = $json->binary ([$enable])\n$enabled = $json = $json->getbinary\nIf the $enable argument is true (or missing), then the \"encode\" method will not try to\ndetect an UTF-8 encoding in any JSON string, it will strictly interpret it as byte sequence.\nThe result might contain new \"\\xNN\" sequences, which is unparsable JSON. The \"decode\" method\nforbids \"\\uNNNN\" sequences and accepts \"\\xNN\" and octal \"\\NNN\" sequences.\n\nThere is also a special logic for perl 5.6 and utf8. 5.6 encodes any string to utf-8\nautomatically when seeing a codepoint >= 0x80 and < 0x100. With the binary flag enabled\ndecode the perl utf8 encoded string to the original byte encoding and encode this with\n\"\\xNN\" escapes. This will result to the same encodings as with newer perls. But note that\nbinary multi-byte codepoints with 5.6 will result in \"illegal unicode character in binary\nstring\" errors, unlike with newer perls.\n\nIf $enable is false, then the \"encode\" method will smartly try to detect Unicode characters\nunless required by the JSON syntax or other flags and hex and octal sequences are forbidden.\n\nSee also the section *ENCODING/CODESET FLAG NOTES* later in this document.\n\nThe main use for this flag is to avoid the smart unicode detection and possible double\nencoding. The disadvantage is that the resulting JSON text is encoded in new \"\\xNN\" and in\nlatin1 characters and must correctly be treated as such when storing and transferring, a\nrare encoding for JSON. It will produce non-readable JSON strings in the browser. It is\ntherefore most useful when you want to store data structures known to contain binary data\nefficiently in files or databases, not when talking to other JSON encoders/decoders. The\nbinary decoding method can also be used when an encoder produced a non-JSON conformant hex\nor octal encoding \"\\xNN\" or \"\\NNN\".\n\nCpanel::JSON::XS->new->binary->encode ([\"\\x{89}\\x{abc}\"])\n5.6:   Error: malformed or illegal unicode character in binary string\n>=5.8: ['\\x89\\xe0\\xaa\\xbc']\n\nCpanel::JSON::XS->new->binary->encode ([\"\\x{89}\\x{bc}\"])\n=> [\"\\x89\\xbc\"]\n\nCpanel::JSON::XS->new->binary->decode ([\"\\x89\\ua001\"])\nError: malformed or illegal unicode character in binary string\n\nCpanel::JSON::XS->new->decode ([\"\\x89\"])\nError: illegal hex character in non-binary string\n\n$json = $json->utf8 ([$enable])\n$enabled = $json->getutf8\nIf $enable is true (or missing), then the \"encode\" method will encode the JSON result into\nUTF-8, as required by many protocols, while the \"decode\" method expects to be handled an\nUTF-8-encoded string. Please note that UTF-8-encoded strings do not contain any characters\noutside the range 0..255, they are thus useful for bytewise/binary I/O. In future versions,\nenabling this option might enable autodetection of the UTF-16 and UTF-32 encoding families,\nas described in RFC4627.\n\nIf $enable is false, then the \"encode\" method will return the JSON string as a (non-encoded)\nUnicode string, while \"decode\" expects thus a Unicode string. Any decoding or encoding (e.g.\nto UTF-8 or UTF-16) needs to be done yourself, e.g. using the Encode module.\n\nSee also the section *ENCODING/CODESET FLAG NOTES* later in this document.\n\nExample, output UTF-16BE-encoded JSON:\n\nuse Encode;\n$jsontext = encode \"UTF-16BE\", Cpanel::JSON::XS->new->encode ($object);\n\nExample, decode UTF-32LE-encoded JSON:\n\nuse Encode;\n$object = Cpanel::JSON::XS->new->decode (decode \"UTF-32LE\", $jsontext);\n\n$json = $json->pretty ([$enable])\nThis enables (or disables) all of the \"indent\", \"spacebefore\" and \"spaceafter\" (and in the\nfuture possibly more) flags in one call to generate the most readable (or most compact) form\npossible.\n\nExample, pretty-print some simple structure:\n\nmy $json = Cpanel::JSON::XS->new->pretty(1)->encode ({a => [1,2]})\n=>\n{\n\"a\" : [\n1,\n2\n]\n}\n\n$json = $json->indent ([$enable])\n$enabled = $json->getindent\nIf $enable is true (or missing), then the \"encode\" method will use a multiline format as\noutput, putting every array member or object/hash key-value pair into its own line,\nindenting them properly.\n\nIf $enable is false, no newlines or indenting will be produced, and the resulting JSON text\nis guaranteed not to contain any \"newlines\".\n\nThis setting has no effect when decoding JSON texts.\n\n$json = $json->indentlength([$numberofspaces])\n$length = $json->getindentlength()\nSet the indent length (default 3). This option is only useful when you also enable indent or\npretty. The acceptable range is from 0 (no indentation) to 15\n\n$json = $json->spacebefore ([$enable])\n$enabled = $json->getspacebefore\nIf $enable is true (or missing), then the \"encode\" method will add an extra optional space\nbefore the \":\" separating keys from values in JSON objects.\n\nIf $enable is false, then the \"encode\" method will not add any extra space at those places.\n\nThis setting has no effect when decoding JSON texts. You will also most likely combine this\nsetting with \"spaceafter\".\n\nExample, spacebefore enabled, spaceafter and indent disabled:\n\n{\"key\" :\"value\"}\n\n$json = $json->spaceafter ([$enable])\n$enabled = $json->getspaceafter\nIf $enable is true (or missing), then the \"encode\" method will add an extra optional space\nafter the \":\" separating keys from values in JSON objects and extra whitespace after the \",\"\nseparating key-value pairs and array members.\n\nIf $enable is false, then the \"encode\" method will not add any extra space at those places.\n\nThis setting has no effect when decoding JSON texts.\n\nExample, spacebefore and indent disabled, spaceafter enabled:\n\n{\"key\": \"value\"}\n\n$json = $json->relaxed ([$enable])\n$enabled = $json->getrelaxed\nIf $enable is true (or missing), then \"decode\" will accept some extensions to normal JSON\nsyntax (see below). \"encode\" will not be affected in anyway. *Be aware that this option\nmakes you accept invalid JSON texts as if they were valid!*. I suggest only to use this\noption to parse application-specific files written by humans (configuration files, resource\nfiles etc.)\n\nIf $enable is false (the default), then \"decode\" will only accept valid JSON texts.\n\nCurrently accepted extensions are:\n\n*   list items can have an end-comma\n\nJSON *separates* array elements and key-value pairs with commas. This can be annoying if\nyou write JSON texts manually and want to be able to quickly append elements, so this\nextension accepts comma at the end of such items not just between them:\n\n[\n1,\n2, <- this comma not normally allowed\n]\n{\n\"k1\": \"v1\",\n\"k2\": \"v2\", <- this comma not normally allowed\n}\n\n*   shell-style '#'-comments\n\nWhenever JSON allows whitespace, shell-style comments are additionally allowed. They are\nterminated by the first carriage-return or line-feed character, after which more\nwhite-space and comments are allowed.\n\n[\n1, # this comment not allowed in JSON\n# neither this one...\n]\n\n*   literal ASCII TAB characters in strings\n\nLiteral ASCII TAB characters are now allowed in strings (and treated as \"\\t\") in relaxed\nmode. Despite JSON mandates, that TAB character is substituted for \"\\t\" sequence.\n\n[\n\"Hello\\tWorld\",\n\"Hello<TAB>World\", # literal <TAB> would not normally be allowed\n]\n\n*   allowsinglequote\n\nSingle quotes are accepted instead of double quotes. See the \"allowsinglequote\" option.\n\n{ \"foo\":'bar' }\n{ 'foo':\"bar\" }\n{ 'foo':'bar' }\n\n*   allowbarekey\n\nAccept unquoted object keys instead of with mandatory double quotes. See the\n\"allowbarekey\" option.\n\n{ foo:\"bar\" }\n\n*   allowdupkeys\n\nAllow decoding of duplicate keys in hashes. By default duplicate keys are forbidden. See\n<http://seriot.ch/parsingjson.php#24>: RFC 7159 section 4: \"The names within an object\nshould be unique.\" See the \"allowdupkeys\" option.\n\n$json = $json->canonical ([$enable])\n$enabled = $json->getcanonical\nIf $enable is true (or missing), then the \"encode\" method will output JSON objects by\nsorting their keys. This is adding a comparatively high overhead.\n\nIf $enable is false, then the \"encode\" method will output key-value pairs in the order Perl\nstores them (which will likely change between runs of the same script, and can change even\nwithin the same run from 5.18 onwards).\n\nThis option is useful if you want the same data structure to be encoded as the same JSON\ntext (given the same overall settings). If it is disabled, the same hash might be encoded\ndifferently even if contains the same data, as key-value pairs have no inherent ordering in\nPerl.\n\nThis setting has no effect when decoding JSON texts.\n\nThis is now also done with tied hashes, contrary to JSON::XS. But note that with most large\ntied hashes stored as tree it is advised to sort the iterator already and don't sort the\nhash output here. Most such iterators are already sorted, as such e.g. DBFile with\n\"DBBTREE\".\n\n$json = $json->sortby (undef, 0, 1 or a block)\nThis currently only (un)sets the \"canonical\" option, and ignores custom sort blocks.\n\nThis setting has no effect when decoding JSON texts.\n\nThis setting has currently no effect on tied hashes.\n\n$json = $json->escapeslash ([$enable])\n$enabled = $json->getescapeslash\nAccording to the JSON Grammar, the *forward slash* character (U+002F) \"/\" need to be\nescaped. But by default strings are encoded without escaping slashes in all perl JSON\nencoders.\n\nIf $enable is true (or missing), then \"encode\" will escape slashes, \"\\/\".\n\nThis setting has no effect when decoding JSON texts.\n\n$json = $json->unblessedbool ([$enable])\n$enabled = $json->getunblessedbool\n$json = $json->unblessedbool([$enable])\n\nIf $enable is true (or missing), then \"decode\" will return Perl non-object boolean variables\n(1 and 0) for JSON booleans (\"true\" and \"false\"). If $enable is false, then \"decode\" will\nreturn \"JSON::PP::Boolean\" objects for JSON booleans.\n\n$json = $json->allowsinglequote ([$enable])\n$enabled = $json->getallowsinglequote\n$json = $json->allowsinglequote([$enable])\n\nIf $enable is true (or missing), then \"decode\" will accept JSON strings quoted by single\nquotations that are invalid JSON format.\n\n$json->allowsinglequote->decode({\"foo\":'bar'});\n$json->allowsinglequote->decode({'foo':\"bar\"});\n$json->allowsinglequote->decode({'foo':'bar'});\n\nThis is also enabled with \"relaxed\". As same as the \"relaxed\" option, this option may be\nused to parse application-specific files written by humans.\n\n$json = $json->allowbarekey ([$enable])\n$enabled = $json->getallowbarekey\n$json = $json->allowbarekey([$enable])\n\nIf $enable is true (or missing), then \"decode\" will accept bare keys of JSON object that are\ninvalid JSON format.\n\nSame as with the \"relaxed\" option, this option may be used to parse application-specific\nfiles written by humans.\n\n$json->allowbarekey->decode('{foo:\"bar\"}');\n\n$json = $json->allowbignum ([$enable])\n$enabled = $json->getallowbignum\n$json = $json->allowbignum([$enable])\n\nIf $enable is true (or missing), then \"decode\" will convert the big integer Perl cannot\nhandle as integer into a Math::BigInt object and convert a floating number (any) into a\nMath::BigFloat.\n\nOn the contrary, \"encode\" converts \"Math::BigInt\" objects and \"Math::BigFloat\" objects into\nJSON numbers with \"allowblessed\" enable.\n\n$json->allownonref->allowblessed->allowbignum;\n$bigfloat = $json->decode('2.000000000000000000000000001');\nprint $json->encode($bigfloat);\n# => 2.000000000000000000000000001\n\nSee \"MAPPING\" about the normal conversion of JSON number.\n\n$json = $json->allowbigint ([$enable])\nThis option is obsolete and replaced by allowbignum.\n\n$json = $json->allownonref ([$enable])\n$enabled = $json->getallownonref\nIf $enable is true (or missing), then the \"encode\" method can convert a non-reference into\nits corresponding string, number or null JSON value, which is an extension to RFC4627.\nLikewise, \"decode\" will accept those JSON values instead of croaking.\n\nIf $enable is false, then the \"encode\" method will croak if it isn't passed an arrayref or\nhashref, as JSON texts must either be an object or array. Likewise, \"decode\" will croak if\ngiven something that is not a JSON object or array.\n\nExample, encode a Perl scalar as JSON value with enabled \"allownonref\", resulting in an\ninvalid JSON text:\n\nCpanel::JSON::XS->new->allownonref->encode (\"Hello, World!\")\n=> \"Hello, World!\"\n\n$json = $json->allowunknown ([$enable])\n$enabled = $json->getallowunknown\nIf $enable is true (or missing), then \"encode\" will *not* throw an exception when it\nencounters values it cannot represent in JSON (for example, filehandles) but instead will\nencode a JSON \"null\" value. Note that blessed objects are not included here and are handled\nseparately by c<allownonref>.\n\nIf $enable is false (the default), then \"encode\" will throw an exception when it encounters\nanything it cannot encode as JSON.\n\nThis option does not affect \"decode\" in any way, and it is recommended to leave it off\nunless you know your communications partner.\n\n$json = $json->allowstringify ([$enable])\n$enabled = $json->getallowstringify\nIf $enable is true (or missing), then \"encode\" will stringify the non-object perl value or\nreference. Note that blessed objects are not included here and are handled separately by\n\"allowblessed\" and \"convertblessed\". String references are stringified to the string\nvalue, other references as in perl.\n\nThis option does not affect \"decode\" in any way.\n\nThis option is special to this module, it is not supported by other encoders. So it is not\nrecommended to use it.\n\n$json = $json->requiretypes ([$enable])\n$enable = $json->getrequiretypes\n$json = $json->requiretypes([$enable])\n\nIf $enable is true (or missing), then \"encode\" will require either enabled \"typeallstring\"\nor second argument with supplied JSON types. See Cpanel::JSON::XS::Type. When\n\"typeallstring\" is not enabled or second argument is not provided (or is undef), then\n\"encode\" croaks. It also croaks when the type for provided structure in \"encode\" is\nincomplete.\n\n$json = $json->typeallstring ([$enable])\n$enable = $json->gettypeallstring\n$json = $json->typeallstring([$enable])\n\nIf $enable is true (or missing), then \"encode\" will always produce stable deterministic JSON\nstring types in resulted output.\n\nWhen $enable is false, then result of encoded JSON output may be different for different\nPerl versions and may depends on loaded modules.\n\nThis is useful it you need deterministic JSON types, independently of used Perl version and\nother modules, but do not want to write complicated type definitions for\nCpanel::JSON::XS::Type.\n\n$json = $json->allowdupkeys ([$enable])\n$enabled = $json->getallowdupkeys\nIf $enable is true (or missing), then the \"decode\" method will not die when it encounters\nduplicate keys in a hash. \"allowdupkeys\" is also enabled in the \"relaxed\" mode.\n\nThe JSON spec allows duplicate name in objects but recommends to disable it, however with\nPerl hashes they are impossible, parsing JSON in Perl silently ignores duplicate names,\nusing the last value found.\n\nSee <http://seriot.ch/parsingjson.php#24>: RFC 7159 section 4: \"The names within an object\nshould be unique.\"\n\n$json = $json->allowblessed ([$enable])\n$enabled = $json->getallowblessed\nIf $enable is true (or missing), then the \"encode\" method will not barf when it encounters a\nblessed reference. Instead, the value of the convertblessed option will decide whether\n\"null\" (\"convertblessed\" disabled or no \"TOJSON\" method found) or a representation of the\nobject (\"convertblessed\" enabled and \"TOJSON\" method found) is being encoded. Has no\neffect on \"decode\".\n\nIf $enable is false (the default), then \"encode\" will throw an exception when it encounters\na blessed object without \"convertblessed\" and a \"TOJSON\" method.\n\nThis setting has no effect on \"decode\".\n\n$json = $json->convertblessed ([$enable])\n$enabled = $json->getconvertblessed\nIf $enable is true (or missing), then \"encode\", upon encountering a blessed object, will\ncheck for the availability of the \"TOJSON\" method on the object's class. If found, it will\nbe called in scalar context and the resulting scalar will be encoded instead of the object.\nIf no \"TOJSON\" method is found, a stringification overload method is tried next. If both\nare not found, the value of \"allowblessed\" will decide what to do.\n\nThe \"TOJSON\" method may safely call die if it wants. If \"TOJSON\" returns other blessed\nobjects, those will be handled in the same way. \"TOJSON\" must take care of not causing an\nendless recursion cycle (== crash) in this case. The same care must be taken with calling\nencode in stringify overloads (even if this works by luck in older perls) or other\ncallbacks. The name of \"TOJSON\" was chosen because other methods called by the Perl core\n(== not by the user of the object) are usually in upper case letters and to avoid collisions\nwith any \"tojson\" function or method.\n\nIf $enable is false (the default), then \"encode\" will not consider this type of conversion.\n\nThis setting has no effect on \"decode\".\n\n$json = $json->allowtags ([$enable])\n$enabled = $json->getallowtags\nSee \"OBJECT SERIALIZATION\" for details.\n\nIf $enable is true (or missing), then \"encode\", upon encountering a blessed object, will\ncheck for the availability of the \"FREEZE\" method on the object's class. If found, it will\nbe used to serialize the object into a nonstandard tagged JSON value (that JSON decoders\ncannot decode).\n\nIt also causes \"decode\" to parse such tagged JSON values and deserialize them via a call to\nthe \"THAW\" method.\n\nIf $enable is false (the default), then \"encode\" will not consider this type of conversion,\nand tagged JSON values will cause a parse error in \"decode\", as if tags were not part of the\ngrammar.\n\n$json = $json->filterjsonobject ([$coderef->($hashref)])\nWhen $coderef is specified, it will be called from \"decode\" each time it decodes a JSON\nobject. The only argument is a reference to the newly-created hash. If the code references\nreturns a single scalar (which need not be a reference), this value (i.e. a copy of that\nscalar to avoid aliasing) is inserted into the deserialized data structure. If it returns an\nempty list (NOTE: *not* \"undef\", which is a valid scalar), the original deserialized hash\nwill be inserted. This setting can slow down decoding considerably.\n\nWhen $coderef is omitted or undefined, any existing callback will be removed and \"decode\"\nwill not change the deserialized hash in any way.\n\nExample, convert all JSON objects into the integer 5:\n\nmy $js = Cpanel::JSON::XS->new->filterjsonobject (sub { 5 });\n# returns [5]\n$js->decode ('[{}]')\n# throw an exception because allownonref is not enabled\n# so a lone 5 is not allowed.\n$js->decode ('{\"a\":1, \"b\":2}');\n\n$json = $json->filterjsonsinglekeyobject ($key [=> $coderef->($value)])\nWorks remotely similar to \"filterjsonobject\", but is only called for JSON objects having a\nsingle key named $key.\n\nThis $coderef is called before the one specified via \"filterjsonobject\", if any. It gets\npassed the single value in the JSON object. If it returns a single value, it will be\ninserted into the data structure. If it returns nothing (not even \"undef\" but the empty\nlist), the callback from \"filterjsonobject\" will be called next, as if no single-key\ncallback were specified.\n\nIf $coderef is omitted or undefined, the corresponding callback will be disabled. There can\nonly ever be one callback for a given key.\n\nAs this callback gets called less often then the \"filterjsonobject\" one, decoding speed\nwill not usually suffer as much. Therefore, single-key objects make excellent targets to\nserialize Perl objects into, especially as single-key JSON objects are as close to the\ntype-tagged value concept as JSON gets (it's basically an ID/VALUE tuple). Of course, JSON\ndoes not support this in any way, so you need to make sure your data never looks like a\nserialized Perl hash.\n\nTypical names for the single object key are \"classwhatever\", or\n\"$dollarsarerarelyused$\" or \"}uglybraceplacement\", or even things like\n\"classmd5sum(classname)\", to reduce the risk of clashing with real hashes.\n\nExample, decode JSON objects of the form \"{ \"widget\" => <id> }\" into the corresponding\n$WIDGET{<id>} object:\n\n# return whatever is in $WIDGET{5}:\nCpanel::JSON::XS\n->new\n->filterjsonsinglekeyobject (widget => sub {\n$WIDGET{ $[0] }\n})\n->decode ('{\"widget\": 5')\n\n# this can be used with a TOJSON method in some \"widget\" class\n# for serialization to json:\nsub WidgetBase::TOJSON {\nmy ($self) = @;\n\nunless ($self->{id}) {\n$self->{id} = ..get..some..id..;\n$WIDGET{$self->{id}} = $self;\n}\n\n{ widget => $self->{id} }\n}\n\n$json = $json->shrink ([$enable])\n$enabled = $json->getshrink\nPerl usually over-allocates memory a bit when allocating space for strings. This flag\noptionally resizes strings generated by either \"encode\" or \"decode\" to their minimum size\npossible. This can save memory when your JSON texts are either very very long or you have\nmany short strings. It will also try to downgrade any strings to octet-form if possible:\nperl stores strings internally either in an encoding called UTF-X or in octet-form. The\nlatter cannot store everything but uses less space in general (and some buggy Perl or C code\nmight even rely on that internal representation being used).\n\nThe actual definition of what shrink does might change in future versions, but it will\nalways try to save space at the expense of time.\n\nIf $enable is true (or missing), the string returned by \"encode\" will be shrunk-to-fit,\nwhile all strings generated by \"decode\" will also be shrunk-to-fit.\n\nIf $enable is false, then the normal perl allocation algorithms are used. If you work with\nyour data, then this is likely to be faster.\n\nIn the future, this setting might control other things, such as converting strings that look\nlike integers or floats into integers or floats internally (there is no difference on the\nPerl level), saving space.\n\n$json = $json->maxdepth ([$maximumnestingdepth])\n$maxdepth = $json->getmaxdepth\nSets the maximum nesting level (default 512) accepted while encoding or decoding. If a\nhigher nesting level is detected in JSON text or a Perl data structure, then the encoder and\ndecoder will stop and croak at that point.\n\nNesting level is defined by number of hash- or arrayrefs that the encoder needs to traverse\nto reach a given point or the number of \"{\" or \"[\" characters without their matching closing\nparenthesis crossed to reach a given character in a string.\n\nSetting the maximum depth to one disallows any nesting, so that ensures that the object is\nonly a single hash/object or array.\n\nIf no argument is given, the highest possible setting will be used, which is rarely useful.\n\nNote that nesting is implemented by recursion in C. The default value has been chosen to be\nas large as typical operating systems allow without crashing.\n\nSee \"SECURITY CONSIDERATIONS\", below, for more info on why this is useful.\n\n$json = $json->maxsize ([$maximumstringsize])\n$maxsize = $json->getmaxsize\nSet the maximum length a JSON text may have (in bytes) where decoding is being attempted.\nThe default is 0, meaning no limit. When \"decode\" is called on a string that is longer then\nthis many bytes, it will not attempt to decode the string but throw an exception. This\nsetting has no effect on \"encode\" (yet).\n\nIf no argument is given, the limit check will be deactivated (same as when 0 is specified).\n\nSee \"SECURITY CONSIDERATIONS\", below, for more info on why this is useful.\n\n$json->stringifyinfnan ([$infnanmode = 1])\n$infnanmode = $json->getstringifyinfnan\nGet or set how Cpanel::JSON::XS encodes \"inf\", \"-inf\" or \"nan\" for numeric values. Also\nqnan, snan or negative nan on some platforms.\n\n\"null\": infnanmode = 0. Similar to most JSON modules in other languages. Always null.\n\nstringified: infnanmode = 1. As in Mojo::JSON. Platform specific strings. Stringified via\nsprintf(%g), with double quotes.\n\ninf/nan: infnanmode = 2. As in JSON::XS, and older releases. Passes through platform\ndependent values, invalid JSON. Stringified via sprintf(%g), but without double quotes.\n\n\"inf/-inf/nan\": infnanmode = 3. Platform independent inf/nan/-inf strings. No\nQNAN/SNAN/negative NAN support, unified to \"nan\". Much easier to detect, but may conflict\nwith valid strings.\n\n$jsontext = $json->encode ($perlscalar, $jsontype)\nConverts the given Perl data structure (a simple scalar or a reference to a hash or array)\nto its JSON representation. Simple scalars will be converted into JSON string or number\nsequences, while references to arrays become JSON arrays and references to hashes become\nJSON objects. Undefined Perl values (e.g. \"undef\") become JSON \"null\" values. Neither \"true\"\nnor \"false\" values will be generated.\n\nFor the type argument see Cpanel::JSON::XS::Type.\n\n$perlscalar = $json->decode ($jsontext, my $jsontype)\nThe opposite of \"encode\": expects a JSON text and tries to parse it, returning the resulting\nsimple scalar or reference. Croaks on error.\n\nJSON numbers and strings become simple Perl scalars. JSON arrays become Perl arrayrefs and\nJSON objects become Perl hashrefs. \"true\" becomes 1, \"false\" becomes 0 and \"null\" becomes\n\"undef\".\n\nFor the type argument see Cpanel::JSON::XS::Type.\n\n($perlscalar, $characters) = $json->decodeprefix ($jsontext)\nThis works like the \"decode\" method, but instead of raising an exception when there is\ntrailing garbage after the first JSON object, it will silently stop parsing there and return\nthe number of characters consumed so far.\n\nThis is useful if your JSON texts are not delimited by an outer protocol and you need to\nknow where the JSON text ends.\n\nCpanel::JSON::XS->new->decodeprefix (\"[1] the tail\")\n=> ([1], 3)\n\n$json->tojson ($perlhashorarrayref)\nDeprecated method for perl 5.8 and newer. Use encodejson instead.\n\n$json->fromjson ($utf8encodedjsontext)\nDeprecated method for perl 5.8 and newer. Use decodejson instead.\n",
            "subsections": []
        },
        "INCREMENTAL PARSING": {
            "content": "In some cases, there is the need for incremental parsing of JSON texts. While this module always\nhas to keep both JSON text and resulting Perl data structure in memory at one time, it does\nallow you to parse a JSON stream incrementally. It does so by accumulating text until it has a\nfull JSON object, which it then can decode. This process is similar to using \"decodeprefix\" to\nsee if a full JSON object is available, but is much more efficient (and can be implemented with\na minimum of method calls).\n\nCpanel::JSON::XS will only attempt to parse the JSON text once it is sure it has enough text to\nget a decisive result, using a very simple but truly incremental parser. This means that it\nsometimes won't stop as early as the full parser, for example, it doesn't detect mismatched\nparentheses. The only thing it guarantees is that it starts decoding as soon as a syntactically\nvalid JSON text has been seen. This means you need to set resource limits (e.g. \"maxsize\") to\nensure the parser will stop parsing in the presence if syntax errors.\n\nThe following methods implement this incremental parser.\n\n[void, scalar or list context] = $json->incrparse ([$string])\nThis is the central parsing function. It can both append new text and extract objects from\nthe stream accumulated so far (both of these functions are optional).\n\nIf $string is given, then this string is appended to the already existing JSON fragment\nstored in the $json object.\n\nAfter that, if the function is called in void context, it will simply return without doing\nanything further. This can be used to add more text in as many chunks as you want.\n\nIf the method is called in scalar context, then it will try to extract exactly *one* JSON\nobject. If that is successful, it will return this object, otherwise it will return \"undef\".\nIf there is a parse error, this method will croak just as \"decode\" would do (one can then\nuse \"incrskip\" to skip the erroneous part). This is the most common way of using the\nmethod.\n\nAnd finally, in list context, it will try to extract as many objects from the stream as it\ncan find and return them, or the empty list otherwise. For this to work, there must be no\nseparators between the JSON objects or arrays, instead they must be concatenated\nback-to-back. If an error occurs, an exception will be raised as in the scalar context case.\nNote that in this case, any previously-parsed JSON texts will be lost.\n\nExample: Parse some JSON arrays/objects in a given string and return them.\n\nmy @objs = Cpanel::JSON::XS->new->incrparse (\"[5][7][1,2]\");\n\n$lvaluestring = $json->incrtext (>5.8 only)\nThis method returns the currently stored JSON fragment as an lvalue, that is, you can\nmanipulate it. This *only* works when a preceding call to \"incrparse\" in *scalar context*\nsuccessfully returned an object, and 2. only with Perl >= 5.8\n\nUnder all other circumstances you must not call this function (I mean it. although in simple\ntests it might actually work, it *will* fail under real world conditions). As a special\nexception, you can also call this method before having parsed anything.\n\nThis function is useful in two cases: a) finding the trailing text after a JSON object or b)\nparsing multiple JSON objects separated by non-JSON text (such as commas).\n\n$json->incrskip\nThis will reset the state of the incremental parser and will remove the parsed text from the\ninput buffer so far. This is useful after \"incrparse\" died, in which case the input buffer\nand incremental parser state is left unchanged, to skip the text parsed so far and to reset\nthe parse state.\n\nThe difference to \"incrreset\" is that only text until the parse error occurred is removed.\n\n$json->incrreset\nThis completely resets the incremental parser, that is, after this call, it will be as if\nthe parser had never parsed anything.\n\nThis is useful if you want to repeatedly parse JSON objects and want to ignore any trailing\ndata, which means you have to reset the parser after each successful decode.\n\nLIMITATIONS\nAll options that affect decoding are supported, except \"allownonref\". The reason for this is\nthat it cannot be made to work sensibly: JSON objects and arrays are self-delimited, i.e. you\ncan concatenate them back to back and still decode them perfectly. This does not hold true for\nJSON numbers, however.\n\nFor example, is the string 1 a single JSON number, or is it simply the start of 12? Or is 12 a\nsingle JSON number, or the concatenation of 1 and 2? In neither case you can tell, and this is\nwhy Cpanel::JSON::XS takes the conservative route and disallows this case.\n\nEXAMPLES\nSome examples will make all this clearer. First, a simple example that works similarly to\n\"decodeprefix\": We want to decode the JSON object at the start of a string and identify the\nportion after the JSON object:\n\nmy $text = \"[1,2,3] hello\";\n\nmy $json = new Cpanel::JSON::XS;\n\nmy $obj = $json->incrparse ($text)\nor die \"expected JSON object or array at beginning of string\";\n\nmy $tail = $json->incrtext;\n# $tail now contains \" hello\"\n\nEasy, isn't it?\n\nNow for a more complicated example: Imagine a hypothetical protocol where you read some requests\nfrom a TCP stream, and each request is a JSON array, without any separation between them (in\nfact, it is often useful to use newlines as \"separators\", as these get interpreted as whitespace\nat the start of the JSON text, which makes it possible to test said protocol with \"telnet\"...).\n\nHere is how you'd do it (it is trivial to write this in an event-based manner):\n\nmy $json = new Cpanel::JSON::XS;\n\n# read some data from the socket\nwhile (sysread $socket, my $buf, 4096) {\n\n# split and decode as many requests as possible\nfor my $request ($json->incrparse ($buf)) {\n# act on the $request\n}\n}\n\nAnother complicated example: Assume you have a string with JSON objects or arrays, all separated\nby (optional) comma characters (e.g. \"[1],[2], [3]\"). To parse them, we have to skip the commas\nbetween the JSON texts, and here is where the lvalue-ness of \"incrtext\" comes in useful:\n\nmy $text = \"[1],[2], [3]\";\nmy $json = new Cpanel::JSON::XS;\n\n# void context, so no parsing done\n$json->incrparse ($text);\n\n# now extract as many objects as possible. note the\n# use of scalar context so incrtext can be called.\nwhile (my $obj = $json->incrparse) {\n# do something with $obj\n\n# now skip the optional comma\n$json->incrtext =~ s/^ \\s* , //x;\n}\n\nNow lets go for a very complex example: Assume that you have a gigantic JSON array-of-objects,\nmany gigabytes in size, and you want to parse it, but you cannot load it into memory fully (this\nhas actually happened in the real world :).\n\nWell, you lost, you have to implement your own JSON parser. But Cpanel::JSON::XS can still help\nyou: You implement a (very simple) array parser and let JSON decode the array elements, which\nare all full JSON objects on their own (this wouldn't work if the array elements could be JSON\nnumbers, for example):\n\nmy $json = new Cpanel::JSON::XS;\n\n# open the monster\nopen my $fh, \"<bigfile.json\"\nor die \"bigfile: $!\";\n\n# first parse the initial \"[\"\nfor (;;) {\nsysread $fh, my $buf, 65536\nor die \"read error: $!\";\n$json->incrparse ($buf); # void context, so no parsing\n\n# Exit the loop once we found and removed(!) the initial \"[\".\n# In essence, we are (ab-)using the $json object as a simple scalar\n# we append data to.\nlast if $json->incrtext =~ s/^ \\s* \\[ //x;\n}\n\n# now we have the skipped the initial \"[\", so continue\n# parsing all the elements.\nfor (;;) {\n# in this loop we read data until we got a single JSON object\nfor (;;) {\nif (my $obj = $json->incrparse) {\n# do something with $obj\nlast;\n}\n\n# add more data\nsysread $fh, my $buf, 65536\nor die \"read error: $!\";\n$json->incrparse ($buf); # void context, so no parsing\n}\n\n# in this loop we read data until we either found and parsed the\n# separating \",\" between elements, or the final \"]\"\nfor (;;) {\n# first skip whitespace\n$json->incrtext =~ s/^\\s*//;\n\n# if we find \"]\", we are done\nif ($json->incrtext =~ s/^\\]//) {\nprint \"finished.\\n\";\nexit;\n}\n\n# if we find \",\", we can continue with the next element\nif ($json->incrtext =~ s/^,//) {\nlast;\n}\n\n# if we find anything else, we have a parse error!\nif (length $json->incrtext) {\ndie \"parse error near \", $json->incrtext;\n}\n\n# else add more data\nsysread $fh, my $buf, 65536\nor die \"read error: $!\";\n$json->incrparse ($buf); # void context, so no parsing\n}\n\nThis is a complex example, but most of the complexity comes from the fact that we are trying to\nbe correct (bear with me if I am wrong, I never ran the above example :).\n",
            "subsections": []
        },
        "BOM": {
            "content": "Detect all unicode Byte Order Marks on decode. Which are UTF-8, UTF-16LE, UTF-16BE, UTF-32LE and\nUTF-32BE.\n\nThe BOM encoding is set only for one specific decode call, it does not change the state of the\nJSON object.\n\nWarning: With perls older than 5.20 you need load the Encode module before loading a multibyte\nBOM, i.e. >= UTF-16. Otherwise an error is thrown. This is an implementation limitation and\nmight get fixed later.\n\nSee <https://tools.ietf.org/html/rfc7159#section-8.1> *\"JSON text SHALL be encoded in UTF-8,\nUTF-16, or UTF-32.\"*\n\n*\"Implementations MUST NOT add a byte order mark to the beginning of a JSON text\",\n\"implementations (...) MAY ignore the presence of a byte order mark rather than treating it as\nan error\".*\n\nSee also <http://www.unicode.org/faq/utfbom.html#BOM>.\n\nBeware that Cpanel::JSON::XS is currently the only JSON module which does accept and decode a\nBOM.\n\nThe latest JSON spec <https://www.greenbytes.de/tech/webdav/rfc8259.html#character.encoding>\nforbid the usage of UTF-16 or UTF-32, the character encoding is UTF-8. Thus in subsequent\nupdates BOM's of UTF-16 or UTF-32 will throw an error.\n",
            "subsections": []
        },
        "MAPPING": {
            "content": "This section describes how Cpanel::JSON::XS maps Perl values to JSON values and vice versa.\nThese mappings are designed to \"do the right thing\" in most circumstances automatically,\npreserving round-tripping characteristics (what you put in comes out as something equivalent).\n\nFor the more enlightened: note that in the following descriptions, lowercase *perl* refers to\nthe Perl interpreter, while uppercase *Perl* refers to the abstract Perl language itself.\n\nJSON -> PERL\nobject\nA JSON object becomes a reference to a hash in Perl. No ordering of object keys is preserved\n(JSON does not preserve object key ordering itself).\n\narray\nA JSON array becomes a reference to an array in Perl.\n\nstring\nA JSON string becomes a string scalar in Perl - Unicode codepoints in JSON are represented\nby the same codepoints in the Perl string, so no manual decoding is necessary.\n\nnumber\nA JSON number becomes either an integer, numeric (floating point) or string scalar in perl,\ndepending on its range and any fractional parts. On the Perl level, there is no difference\nbetween those as Perl handles all the conversion details, but an integer may take slightly\nless memory and might represent more values exactly than floating point numbers.\n\nIf the number consists of digits only, Cpanel::JSON::XS will try to represent it as an\ninteger value. If that fails, it will try to represent it as a numeric (floating point)\nvalue if that is possible without loss of precision. Otherwise it will preserve the number\nas a string value (in which case you lose roundtripping ability, as the JSON number will be\nre-encoded to a JSON string).\n\nNumbers containing a fractional or exponential part will always be represented as numeric\n(floating point) values, possibly at a loss of precision (in which case you might lose\nperfect roundtripping ability, but the JSON number will still be re-encoded as a JSON\nnumber).\n\nNote that precision is not accuracy - binary floating point values cannot represent most\ndecimal fractions exactly, and when converting from and to floating point,\n\"Cpanel::JSON::XS\" only guarantees precision up to but not including the least significant\nbit.\n\ntrue, false\nWhen \"unblessedbool\" is set to true, then JSON \"true\" becomes 1 and JSON \"false\" becomes 0.\n\nOtherwise these JSON atoms become \"JSON::PP::true\" and \"JSON::PP::false\", respectively. They\nare \"JSON::PP::Boolean\" objects and are overloaded to act almost exactly like the numbers 1\nand 0. You can check whether a scalar is a JSON boolean by using the\n\"Cpanel::JSON::XS::isbool\" function.\n\nThe other round, from perl to JSON, \"!0\" which is represented as \"yes\" becomes \"true\", and\n\"!1\" which is represented as \"no\" becomes \"false\".\n\nVia Cpanel::JSON::XS::Type you can now even force negation in \"encode\", without overloading\nof \"!\":\n\nmy $false = Cpanel::JSON::XS::false;\nprint($json->encode([!$false], [JSONTYPEBOOL]));\n=> [true]\n\nnull\nA JSON null atom becomes \"undef\" in Perl.\n\nshell-style comments (\"# *text*\")\nAs a nonstandard extension to the JSON syntax that is enabled by the \"relaxed\" setting,\nshell-style comments are allowed. They can start anywhere outside strings and go till the\nend of the line.\n\ntagged values (\"(*tag*)*value*\").\nAnother nonstandard extension to the JSON syntax, enabled with the \"allowtags\" setting, are\ntagged values. In this implementation, the *tag* must be a perl package/class name encoded\nas a JSON string, and the *value* must be a JSON array encoding optional constructor\narguments.\n\nSee \"OBJECT SERIALIZATION\", below, for details.\n\nPERL -> JSON\nThe mapping from Perl to JSON is slightly more difficult, as Perl is a truly typeless language,\nso we can only guess which JSON type is meant by a Perl value.\n\nhash references\nPerl hash references become JSON objects. As there is no inherent ordering in hash keys (or\nJSON objects), they will usually be encoded in a pseudo-random order that can change between\nruns of the same program but stays generally the same within a single run of a program.\nCpanel::JSON::XS can optionally sort the hash keys (determined by the *canonical* flag), so\nthe same datastructure will serialize to the same JSON text (given same settings and version\nof Cpanel::JSON::XS), but this incurs a runtime overhead and is only rarely useful, e.g.\nwhen you want to compare some JSON text against another for equality.\n\narray references\nPerl array references become JSON arrays.\n\nother references\nOther unblessed references are generally not allowed and will cause an exception to be\nthrown, except for references to the integers 0 and 1, which get turned into \"false\" and\n\"true\" atoms in JSON.\n\nWith the option \"allowstringify\", you can ignore the exception and return the\nstringification of the perl value.\n\nWith the option \"allowunknown\", you can ignore the exception and return \"null\" instead.\n\nencodejson [\\\"x\"]        # => cannot encode reference to scalar 'SCALAR(0x..)'\n# unless the scalar is 0 or 1\nencodejson [\\0, \\1]      # yields [false,true]\n\nallowstringify->encodejson [\\\"x\"] # yields \"x\" unlike JSON::PP\nallowunknown->encodejson [\\\"x\"]   # yields null as in JSON::PP\n\nCpanel::JSON::XS::true, Cpanel::JSON::XS::false\nThese special values become JSON true and JSON false values, respectively. You can also use\n\"\\1\" and \"\\0\" or \"!0\" and \"!1\" directly if you want.\n\nencodejson [Cpanel::JSON::XS::false, Cpanel::JSON::XS::true] # yields [false,true]\nencodejson [!1, !0], [JSONTYPEBOOL, JSONTYPEBOOL] # yields [false,true]\n\neq/ne comparisons with true, false:\n\nfalse is eq to the empty string or the string 'false' or the special empty string \"!!0\" or\n\"!1\", i.e. \"SVNO\", or the numbers 0 or 0.0.\n\ntrue is eq to the string 'true' or to the special string \"!0\" (i.e. \"SVYES\") or to the\nnumbers 1 or 1.0.\n\nblessed objects\nBlessed objects are not directly representable in JSON, but \"Cpanel::JSON::XS\" allows\nvarious optional ways of handling objects. See \"OBJECT SERIALIZATION\", below, for details.\n\nSee the \"allowblessed\" and \"convertblessed\" methods on various options on how to deal with\nthis: basically, you can choose between throwing an exception, encoding the reference as if\nit weren't blessed, use the objects overloaded stringification method or provide your own\nserializer method.\n\nsimple scalars\nSimple Perl scalars (any scalar that is not a reference) are the most difficult objects to\nencode: Cpanel::JSON::XS will encode undefined scalars or inf/nan as JSON \"null\" values and\nother scalars to either number or string in non-deterministic way which may be affected or\nchanged by Perl version or any other loaded Perl module.\n\nIf you want to have stable and deterministic types in JSON encoder then use\nCpanel::JSON::XS::Type.\n\nAlternative way for deterministic types is to use \"typeallstring\" method when all perl\nscalars are encoded to JSON strings.\n\nNon-deterministic behavior is following: scalars that have last been used in a string\ncontext before encoding as JSON strings, and anything else as number value:\n\n# dump as number\nencodejson [2]                      # yields [2]\nencodejson [-3.0e17]                # yields [-3e+17]\nmy $value = 5; encodejson [$value]  # yields [5]\n\n# used as string, but the two representations are for the same number\nprint $value;\nencodejson [$value]                 # yields [5]\n\n# used as different string (non-matching dual-var)\nmy $str = '0 but true';\nmy $num = 1 + $str;\nencodejson [$num, $str]           # yields [1,\"0 but true\"]\n\n# undef becomes null\nencodejson [undef]                  # yields [null]\n\n# inf or nan becomes null, unless you answered\n# \"Do you want to handle inf/nan as strings\" with yes\nencodejson [999]                # yields [null]\n\nYou can force the type to be a JSON string by stringifying it:\n\nmy $x = 3.1; # some variable containing a number\n\"$x\";        # stringified\n$x .= \"\";    # another, more awkward way to stringify\nprint $x;    # perl does it for you, too, quite often\n\nYou can force the type to be a JSON number by numifying it:\n\nmy $x = \"3\"; # some variable containing a string\n$x += 0;     # numify it, ensuring it will be dumped as a number\n$x *= 1;     # same thing, the choice is yours.\n\nNote that numerical precision has the same meaning as under Perl (so binary to decimal\nconversion follows the same rules as in Perl, which can differ to other languages). Also,\nyour perl interpreter might expose extensions to the floating point numbers of your\nplatform, such as infinities or NaN's - these cannot be represented in JSON, and thus null\nis returned instead. Optionally you can configure it to stringify inf and nan values.\n\nOBJECT SERIALIZATION\nAs JSON cannot directly represent Perl objects, you have to choose between a pure JSON\nrepresentation (without the ability to deserialize the object automatically again), and a\nnonstandard extension to the JSON syntax, tagged values.\n\nSERIALIZATION\nWhat happens when \"Cpanel::JSON::XS\" encounters a Perl object depends on the \"allowblessed\",\n\"convertblessed\" and \"allowtags\" settings, which are used in this order:\n\n1. \"allowtags\" is enabled and the object has a \"FREEZE\" method.\nIn this case, \"Cpanel::JSON::XS\" uses the Types::Serialiser object serialization protocol to\ncreate a tagged JSON value, using a nonstandard extension to the JSON syntax.\n\nThis works by invoking the \"FREEZE\" method on the object, with the first argument being the\nobject to serialize, and the second argument being the constant string \"JSON\" to distinguish\nit from other serializers.\n\nThe \"FREEZE\" method can return any number of values (i.e. zero or more). These values and\nthe paclkage/classname of the object will then be encoded as a tagged JSON value in the\nfollowing format:\n\n(\"classname\")[FREEZE return values...]\n\ne.g.:\n\n(\"URI\")[\"http://www.google.com/\"]\n(\"MyDate\")[2013,10,29]\n(\"ImageData::JPEG\")[\"Z3...VlCg==\"]\n\nFor example, the hypothetical \"My::Object\" \"FREEZE\" method might use the objects \"type\" and\n\"id\" members to encode the object:\n\nsub My::Object::FREEZE {\nmy ($self, $serializer) = @;\n\n($self->{type}, $self->{id})\n}\n\n2. \"convertblessed\" is enabled and the object has a \"TOJSON\" method.\nIn this case, the \"TOJSON\" method of the object is invoked in scalar context. It must\nreturn a single scalar that can be directly encoded into JSON. This scalar replaces the\nobject in the JSON text.\n\nFor example, the following \"TOJSON\" method will convert all URI objects to JSON strings\nwhen serialized. The fact that these values originally were URI objects is lost.\n\nsub URI::TOJSON {\nmy ($uri) = @;\n$uri->asstring\n}\n\n3. \"convertblessed\" is enabled and the object has a stringification overload.\nIn this case, the overloaded \"\" method of the object is invoked in scalar context. It must\nreturn a single scalar that can be directly encoded into JSON. This scalar replaces the\nobject in the JSON text.\n\nFor example, the following \"\" method will convert all URI objects to JSON strings when\nserialized. The fact that these values originally were URI objects is lost.\n\npackage URI;\nuse overload '\"\"' => sub { shift->asstring };\n\n4. \"allowblessed\" is enabled.\nThe object will be serialized as a JSON null value.\n\n5. none of the above\nIf none of the settings are enabled or the respective methods are missing,\n\"Cpanel::JSON::XS\" throws an exception.\n\nDESERIALIZATION\nFor deserialization there are only two cases to consider: either nonstandard tagging was used,\nin which case \"allowtags\" decides, or objects cannot be automatically be deserialized, in which\ncase you can use postprocessing or the \"filterjsonobject\" or \"filterjsonsinglekeyobject\"\ncallbacks to get some real objects our of your JSON.\n\nThis section only considers the tagged value case: I a tagged JSON object is encountered during\ndecoding and \"allowtags\" is disabled, a parse error will result (as if tagged values were not\npart of the grammar).\n\nIf \"allowtags\" is enabled, \"Cpanel::JSON::XS\" will look up the \"THAW\" method of the\npackage/classname used during serialization (it will not attempt to load the package as a Perl\nmodule). If there is no such method, the decoding will fail with an error.\n\nOtherwise, the \"THAW\" method is invoked with the classname as first argument, the constant\nstring \"JSON\" as second argument, and all the values from the JSON array (the values originally\nreturned by the \"FREEZE\" method) as remaining arguments.\n\nThe method must then return the object. While technically you can return any Perl scalar, you\nmight have to enable the \"enablenonref\" setting to make that work in all cases, so better\nreturn an actual blessed reference.\n\nAs an example, let's implement a \"THAW\" function that regenerates the \"My::Object\" from the\n\"FREEZE\" example earlier:\n\nsub My::Object::THAW {\nmy ($class, $serializer, $type, $id) = @;\n\n$class->new (type => $type, id => $id)\n}\n\nSee the \"SECURITY CONSIDERATIONS\" section below. Allowing external json objects being\ndeserialized to perl objects is usually a very bad idea.\n",
            "subsections": []
        },
        "ENCODING/CODESET FLAG NOTES": {
            "content": "The interested reader might have seen a number of flags that signify encodings or codesets -\n\"utf8\", \"latin1\", \"binary\" and \"ascii\". There seems to be some confusion on what these do, so\nhere is a short comparison:\n\n\"utf8\" controls whether the JSON text created by \"encode\" (and expected by \"decode\") is UTF-8\nencoded or not, while \"latin1\" and \"ascii\" only control whether \"encode\" escapes character\nvalues outside their respective codeset range. Neither of these flags conflict with each other,\nalthough some combinations make less sense than others.\n\nCare has been taken to make all flags symmetrical with respect to \"encode\" and \"decode\", that\nis, texts encoded with any combination of these flag values will be correctly decoded when the\nsame flags are used - in general, if you use different flag settings while encoding vs. when\ndecoding you likely have a bug somewhere.\n\nBelow comes a verbose discussion of these flags. Note that a \"codeset\" is simply an abstract set\nof character-codepoint pairs, while an encoding takes those codepoint numbers and *encodes*\nthem, in our case into octets. Unicode is (among other things) a codeset, UTF-8 is an encoding,\nand ISO-8859-1 (= latin 1) and ASCII are both codesets *and* encodings at the same time, which\ncan be confusing.\n\n\"utf8\" flag disabled\nWhen \"utf8\" is disabled (the default), then \"encode\"/\"decode\" generate and expect Unicode\nstrings, that is, characters with high ordinal Unicode values (> 255) will be encoded as\nsuch characters, and likewise such characters are decoded as-is, no changes to them will be\ndone, except \"(re-)interpreting\" them as Unicode codepoints or Unicode characters,\nrespectively (to Perl, these are the same thing in strings unless you do funny/weird/dumb\nstuff).\n\nThis is useful when you want to do the encoding yourself (e.g. when you want to have UTF-16\nencoded JSON texts) or when some other layer does the encoding for you (for example, when\nprinting to a terminal using a filehandle that transparently encodes to UTF-8 you certainly\ndo NOT want to UTF-8 encode your data first and have Perl encode it another time).\n\n\"utf8\" flag enabled\nIf the \"utf8\"-flag is enabled, \"encode\"/\"decode\" will encode all characters using the\ncorresponding UTF-8 multi-byte sequence, and will expect your input strings to be encoded as\nUTF-8, that is, no \"character\" of the input string must have any value > 255, as UTF-8 does\nnot allow that.\n\nThe \"utf8\" flag therefore switches between two modes: disabled means you will get a Unicode\nstring in Perl, enabled means you get an UTF-8 encoded octet/binary string in Perl.\n\n\"latin1\", \"binary\" or \"ascii\" flags enabled\nWith \"latin1\" (or \"ascii\") enabled, \"encode\" will escape characters with ordinal values >\n255 (> 127 with \"ascii\") and encode the remaining characters as specified by the \"utf8\"\nflag. With \"binary\" enabled, ordinal values > 255 are illegal.\n\nIf \"utf8\" is disabled, then the result is also correctly encoded in those character sets (as\nboth are proper subsets of Unicode, meaning that a Unicode string with all character values\n< 256 is the same thing as a ISO-8859-1 string, and a Unicode string with all character\nvalues < 128 is the same thing as an ASCII string in Perl).\n\nIf \"utf8\" is enabled, you still get a correct UTF-8-encoded string, regardless of these\nflags, just some more characters will be escaped using \"\\uXXXX\" then before.\n\nNote that ISO-8859-1-*encoded* strings are not compatible with UTF-8 encoding, while\nASCII-encoded strings are. That is because the ISO-8859-1 encoding is NOT a subset of UTF-8\n(despite the ISO-8859-1 *codeset* being a subset of Unicode), while ASCII is.\n\nSurprisingly, \"decode\" will ignore these flags and so treat all input values as governed by\nthe \"utf8\" flag. If it is disabled, this allows you to decode ISO-8859-1- and ASCII-encoded\nstrings, as both strict subsets of Unicode. If it is enabled, you can correctly decode UTF-8\nencoded strings.\n\nSo neither \"latin1\", \"binary\" nor \"ascii\" are incompatible with the \"utf8\" flag - they only\ngovern when the JSON output engine escapes a character or not.\n\nThe main use for \"latin1\" or \"binary\" is to relatively efficiently store binary data as\nJSON, at the expense of breaking compatibility with most JSON decoders.\n\nThe main use for \"ascii\" is to force the output to not contain characters with values > 127,\nwhich means you can interpret the resulting string as UTF-8, ISO-8859-1, ASCII, KOI8-R or\nmost about any character set and 8-bit-encoding, and still get the same data structure back.\nThis is useful when your channel for JSON transfer is not 8-bit clean or the encoding might\nbe mangled in between (e.g. in mail), and works because ASCII is a proper subset of most\n8-bit and multibyte encodings in use in the world.\n\nJSON and ECMAscript\nJSON syntax is based on how literals are represented in javascript (the not-standardized\npredecessor of ECMAscript) which is presumably why it is called \"JavaScript Object Notation\".\n\nHowever, JSON is not a subset (and also not a superset of course) of ECMAscript (the standard)\nor javascript (whatever browsers actually implement).\n\nIf you want to use javascript's \"eval\" function to \"parse\" JSON, you might run into parse errors\nfor valid JSON texts, or the resulting data structure might not be queryable:\n\nOne of the problems is that U+2028 and U+2029 are valid characters inside JSON strings, but are\nnot allowed in ECMAscript string literals, so the following Perl fragment will not output\nsomething that can be guaranteed to be parsable by javascript's \"eval\":\n\nuse Cpanel::JSON::XS;\n\nprint encodejson [chr 0x2028];\n\nThe right fix for this is to use a proper JSON parser in your javascript programs, and not rely\non \"eval\" (see for example Douglas Crockford's json2.js parser).\n\nIf this is not an option, you can, as a stop-gap measure, simply encode to ASCII-only JSON:\n\nuse Cpanel::JSON::XS;\n\nprint Cpanel::JSON::XS->new->ascii->encode ([chr 0x2028]);\n\nNote that this will enlarge the resulting JSON text quite a bit if you have many non-ASCII\ncharacters. You might be tempted to run some regexes to only escape U+2028 and U+2029, e.g.:\n\n# DO NOT USE THIS!\nmy $json = Cpanel::JSON::XS->new->utf8->encode ([chr 0x2028]);\n$json =~ s/\\xe2\\x80\\xa8/\\\\u2028/g; # escape U+2028\n$json =~ s/\\xe2\\x80\\xa9/\\\\u2029/g; # escape U+2029\nprint $json;\n\nNote that *this is a bad idea*: the above only works for U+2028 and U+2029 and thus only for\nfully ECMAscript-compliant parsers. Many existing javascript implementations, however, have\nissues with other characters as well - using \"eval\" naively simply *will* cause problems.\n\nAnother problem is that some javascript implementations reserve some property names for their\nown purposes (which probably makes them non-ECMAscript-compliant). For example, Iceweasel\nreserves the \"proto\" property name for its own purposes.\n\nIf that is a problem, you could parse try to filter the resulting JSON output for these property\nstrings, e.g.:\n\n$json =~ s/\"proto\"\\s*:/\"protorenamed\":/g;\n\nThis works because \"proto\" is not valid outside of strings, so every occurrence of\n\"\"proto\"\\s*:\" must be a string used as property name.\n\nUnicode non-characters between U+FFFD and U+10FFFF are decoded either to the recommended U+FFFD\nREPLACEMENT CHARACTER (see Unicode PR #121: Recommended Practice for Replacement Characters), or\nin the binary or relaxed mode left as is, keeping the illegal non-characters as before.\n\nRaw non-Unicode characters outside the valid unicode range fail now to parse, because \"A string\nis a sequence of zero or more Unicode characters\" RFC 7159 section 1 and \"JSON text SHALL be\nencoded in Unicode RFC 7159 section 8.1. We use now the UTF8DISALLOWSUPER flag when parsing\nunicode.\n\nIf you know of other incompatibilities, please let me know.\n\nJSON and YAML\nYou often hear that JSON is a subset of YAML. *in general, there is no way to configure JSON::XS\nto output a data structure as valid YAML* that works in all cases. If you really must use\nCpanel::JSON::XS to generate YAML, you should use this algorithm (subject to change in future\nversions):\n\nmy $toyaml = Cpanel::JSON::XS->new->utf8->spaceafter (1);\nmy $yaml = $toyaml->encode ($ref) . \"\\n\";\n\nThis will *usually* generate JSON texts that also parse as valid YAML.\n\nSPEED\nIt seems that JSON::XS is surprisingly fast, as shown in the following tables. They have been\ngenerated with the help of the \"eg/bench\" program in the JSON::XS distribution, to make it easy\nto compare on your own system.\n\nJSON::XS is with Data::MessagePack and Sereal one of the fastest serializers, because JSON and\nJSON::XS do not support backrefs (no graph structures), only trees. Storable supports backrefs,\ni.e. graphs. Data::MessagePack encodes its data binary (as Storable) and supports only very\nsimple subset of JSON.\n\nFirst comes a comparison between various modules using a very short single-line JSON string\n(also available at <http://dist.schmorp.de/misc/json/short.json>).\n\n{\"method\": \"handleMessage\", \"params\": [\"user1\",\n\"we were just talking\"], \"id\": null, \"array\":[1,11,234,-5,1e5,1e7,\n1,  0]}\n\nIt shows the number of encodes/decodes per second (JSON::XS uses the functional interface, while\nCpanel::JSON::XS/2 uses the OO interface with pretty-printing and hash key sorting enabled,\nCpanel::JSON::XS/3 enables shrink. JSON::DWIW/DS uses the deserialize function, while\nJSON::DWIW::FJ uses the fromjson method). Higher is better:\n\nmodule        |     encode |     decode |\n--------------|------------|------------|\nJSON::DWIW/DS |  86302.551 | 102300.098 |\nJSON::DWIW/FJ |  86302.551 |  75983.768 |\nJSON::PP      |  15827.562 |   6638.658 |\nJSON::Syck    |  63358.066 |  47662.545 |\nJSON::XS      | 511500.488 | 511500.488 |\nJSON::XS/2    | 291271.111 | 388361.481 |\nJSON::XS/3    | 361577.931 | 361577.931 |\nStorable      |  66788.280 | 265462.278 |\n--------------+------------+------------+\n\nThat is, JSON::XS is almost six times faster than JSON::DWIW on encoding, about five times\nfaster on decoding, and over thirty to seventy times faster than JSON's pure perl\nimplementation. It also compares favourably to Storable for small amounts of data.\n\nUsing a longer test string (roughly 18KB, generated from Yahoo! Locals search API\n(<http://dist.schmorp.de/misc/json/long.json>).\n\nmodule        |     encode |     decode |\n--------------|------------|------------|\nJSON::DWIW/DS |   1647.927 |   2673.916 |\nJSON::DWIW/FJ |   1630.249 |   2596.128 |\nJSON::PP      |    400.640 |     62.311 |\nJSON::Syck    |   1481.040 |   1524.869 |\nJSON::XS      |  20661.596 |   9541.183 |\nJSON::XS/2    |  10683.403 |   9416.938 |\nJSON::XS/3    |  20661.596 |   9400.054 |\nStorable      |  19765.806 |  10000.725 |\n--------------+------------+------------+\n\nAgain, JSON::XS leads by far (except for Storable which non-surprisingly decodes a bit faster).\n\nOn large strings containing lots of high Unicode characters, some modules (such as JSON::PC)\nseem to decode faster than JSON::XS, but the result will be broken due to missing (or wrong)\nUnicode handling. Others refuse to decode or encode properly, so it was impossible to prepare a\nfair comparison table for that case.\n\nFor updated graphs see <https://github.com/Sereal/Sereal/wiki/Sereal-Comparison-Graphs>\n\nINTEROP with JSON and JSON::XS and other JSON modules\nAs long as you only serialize data that can be directly expressed in JSON, \"Cpanel::JSON::XS\" is\nincapable of generating invalid JSON output (modulo bugs, but \"JSON::XS\" has found more bugs in\nthe official JSON testsuite (1) than the official JSON testsuite has found in \"JSON::XS\" (0)).\n\"Cpanel::JSON::XS\" is currently the only known JSON decoder which passes all\n<http://seriot.ch/parsingjson.html> tests, while being the fastest also.\n\nWhen you have trouble decoding JSON generated by this module using other decoders, then it is\nvery likely that you have an encoding mismatch or the other decoder is broken.\n\nWhen decoding, \"JSON::XS\" is strict by default and will likely catch all errors. There are\ncurrently two settings that change this: \"relaxed\" makes \"JSON::XS\" accept (but not generate)\nsome non-standard extensions, and \"allowtags\" or \"allowblessed\" will allow you to encode and\ndecode Perl objects, at the cost of being totally insecure and not outputting valid JSON\nanymore.\n\nJSON-XS-3.01 broke interoperability with JSON-2.90 with booleans. See JSON.\n\nCpanel::JSON::XS needs to know the JSON and JSON::XS versions to be able work with those\nobjects, especially when encoding a booleans like \"{\"istrue\":true}\". So you need to load these\nmodules before.\n\ntrue/false overloading and boolean representations are supported.\n\nJSON::XS and JSON::PP representations are accepted and older JSON::XS accepts Cpanel::JSON::XS\nbooleans. All JSON modules JSON, JSON, PP, JSON::XS, Cpanel::JSON::XS produce JSON::PP::Boolean\nobjects, just Mojo and JSON::YAJL not. Mojo produces Mojo::JSON::Bool and JSON::YAJL::Parser\njust an unblessed IV.\n\nCpanel::JSON::XS accepts JSON::PP::Boolean and Mojo::JSON::Bool objects as booleans.\n\nI cannot think of any reason to still use JSON::XS anymore.\n\nTAGGED VALUE SYNTAX AND STANDARD JSON EN/DECODERS\nWhen you use \"allowtags\" to use the extended (and also nonstandard and invalid) JSON syntax for\nserialized objects, and you still want to decode the generated serialize objects, you can run a\nregex to replace the tagged syntax by standard JSON arrays (it only works for \"normal\" package\nnames without comma, newlines or single colons). First, the readable Perl version:\n\n# if your FREEZE methods return no values, you need this replace first:\n$json =~ s/\\( \\s* (\" (?: [^\\\\\":,]+|\\\\.|::)* \") \\s* \\) \\s* \\[\\s*\\]/[$1]/gx;\n\n# this works for non-empty constructor arg lists:\n$json =~ s/\\( \\s* (\" (?: [^\\\\\":,]+|\\\\.|::)* \") \\s* \\) \\s* \\[/[$1,/gx;\n\nAnd here is a less readable version that is easy to adapt to other languages:\n\n$json =~ s/\\(\\s*(\"([^\\\\\":,]+|\\\\.|::)*\")\\s*\\)\\s*\\[/[$1,/g;\n\nHere is an ECMAScript version (same regex):\n\njson = json.replace (/\\(\\s*(\"([^\\\\\":,]+|\\\\.|::)*\")\\s*\\)\\s*\\[/g, \"[$1,\");\n\nSince this syntax converts to standard JSON arrays, it might be hard to distinguish serialized\nobjects from normal arrays. You can prepend a \"magic number\" as first array element to reduce\nchances of a collision:\n\n$json =~ s/\\(\\s*(\"([^\\\\\":,]+|\\\\.|::)*\")\\s*\\)\\s*\\[/[\"XU1peReLzT4ggEllLanBYq4G9VzliwKF\",$1,/g;\n\nAnd after decoding the JSON text, you could walk the data structure looking for arrays with a\nfirst element of \"XU1peReLzT4ggEllLanBYq4G9VzliwKF\".\n\nThe same approach can be used to create the tagged format with another encoder. First, you\ncreate an array with the magic string as first member, the classname as second, and constructor\narguments last, encode it as part of your JSON structure, and then:\n\n$json =~ s/\\[\\s*\"XU1peReLzT4ggEllLanBYq4G9VzliwKF\"\\s*,\\s*(\"([^\\\\\":,]+|\\\\.|::)*\")\\s*,/($1)[/g;\n\nAgain, this has some limitations - the magic string must not be encoded with character escapes,\nand the constructor arguments must be non-empty.\n",
            "subsections": []
        },
        "RFC7159": {
            "content": "Since this module was written, Google has written a new JSON RFC, RFC 7159 (and RFC7158).\nUnfortunately, this RFC breaks compatibility with both the original JSON specification on\nwww.json.org and RFC4627.\n\nAs far as I can see, you can get partial compatibility when parsing by using \"->allownonref\".\nHowever, consider the security implications of doing so.\n\nI haven't decided yet when to break compatibility with RFC4627 by default (and potentially leave\napplications insecure) and change the default to follow RFC7159, but application authors are\nwell advised to call \"->allownonref(0)\" even if this is the current default, if they cannot\nhandle non-reference values, in preparation for the day when the default will change.\n",
            "subsections": []
        },
        "SECURITY CONSIDERATIONS": {
            "content": "JSON::XS and Cpanel::JSON::XS are not only fast. JSON is generally the most secure serializing\nformat, because it is the only one besides Data::MessagePack, which does not deserialize objects\nper default. For all languages, not just perl. The binary variant BSON (MongoDB) does more but\nis unsafe.\n\nIt is trivial for any attacker to create such serialized objects in JSON and trick perl into\nexpanding them, thereby triggering certain methods. Watch\n<https://www.youtube.com/watch?v=Gzx6KlqiIZE> for an exploit demo for \"CVE-2015-1592 SixApart\nMovableType Storable Perl Code Execution\" for a deserializer which expands objects.\nDeserializing even coderefs (methods, functions) or external data would be considered the most\ndangerous.\n\nSecurity relevant overview of serializers regarding deserializing objects by default:\n\nObjects   Coderefs  External Data\n\nData::Dumper      YES       YES       YES\nStorable          YES       NO (def)  NO\nSereal            YES       NO        NO\nYAML              YES       NO        NO\nB::C              YES       YES       YES\nB::Bytecode       YES       YES       YES\nBSON              YES       YES       NO\nJSON::SL          YES       NO        YES\nJSON              NO (def)  NO        NO\nData::MessagePack NO        NO        NO\nXML               NO        NO        YES\n\nPickle            YES       YES       YES\nPHP Deserialize   YES       NO        NO\n\nWhen you are using JSON in a protocol, talking to untrusted potentially hostile creatures\nrequires relatively few measures.\n\nFirst of all, your JSON decoder should be secure, that is, should not have any buffer overflows.\nObviously, this module should ensure that.\n\nSecond, you need to avoid resource-starving attacks. That means you should limit the size of\nJSON texts you accept, or make sure then when your resources run out, that's just fine (e.g. by\nusing a separate process that can crash safely). The size of a JSON text in octets or characters\nis usually a good indication of the size of the resources required to decode it into a Perl\nstructure. While JSON::XS can check the size of the JSON text, it might be too late when you\nalready have it in memory, so you might want to check the size before you accept the string.\n\nThird, Cpanel::JSON::XS recurses using the C stack when decoding objects and arrays. The C stack\nis a limited resource: for instance, on my amd64 machine with 8MB of stack size I can decode\naround 180k nested arrays but only 14k nested JSON objects (due to perl itself recursing deeply\non croak to free the temporary). If that is exceeded, the program crashes. To be conservative,\nthe default nesting limit is set to 512. If your process has a smaller stack, you should adjust\nthis setting accordingly with the \"maxdepth\" method.\n\nAlso keep in mind that Cpanel::JSON::XS might leak contents of your Perl data structures in its\nerror messages, so when you serialize sensitive information you might want to make sure that\nexceptions thrown by JSON::XS will not end up in front of untrusted eyes.\n\nIf you are using Cpanel::JSON::XS to return packets to consumption by JavaScript scripts in a\nbrowser you should have a look at\n<http://blog.archive.jpsykes.com/47/practical-csrf-and-json-security/> to see whether you are\nvulnerable to some common attack vectors (which really are browser design bugs, but it is still\nyou who will have to deal with it, as major browser developers care only for features, not about\ngetting security right). You might also want to also look at Mojo::JSON special escape rules to\nprevent from XSS attacks.\n\n\"OLD\" VS. \"NEW\" JSON (RFC 4627 VS. RFC 7159)\nTL;DR: Due to security concerns, Cpanel::JSON::XS will not allow scalar data in JSON texts by\ndefault - you need to create your own Cpanel::JSON::XS object and enable \"allownonref\":\n\nmy $json = JSON::XS->new->allownonref;\n\n$text = $json->encode ($data);\n$data = $json->decode ($text);\n\nThe long version: JSON being an important and supposedly stable format, the IETF standardized it\nas RFC 4627 in 2006. Unfortunately the inventor of JSON Douglas Crockford unilaterally changed\nthe definition of JSON in javascript. Rather than create a fork, the IETF decided to standardize\nthe new syntax (apparently, so I as told, without finding it very amusing).\n\nThe biggest difference between the original JSON and the new JSON is that the new JSON supports\nscalars (anything other than arrays and objects) at the top-level of a JSON text. While this is\nstrictly backwards compatible to older versions, it breaks a number of protocols that relied on\nsending JSON back-to-back, and is a minor security concern.\n\nFor example, imagine you have two banks communicating, and on one side, the JSON coder gets\nupgraded. Two messages, such as 10 and 1000 might then be confused to mean 101000, something\nthat couldn't happen in the original JSON, because neither of these messages would be valid\nJSON.\n\nIf one side accepts these messages, then an upgrade in the coder on either side could result in\nthis becoming exploitable.\n\nThis module has always allowed these messages as an optional extension, by default disabled. The\nsecurity concerns are the reason why the default is still disabled, but future versions\nmight/will likely upgrade to the newer RFC as default format, so you are advised to check your\nimplementation and/or override the default with \"->allownonref (0)\" to ensure that future\nversions are safe.\n",
            "subsections": []
        },
        "THREADS": {
            "content": "Cpanel::JSON::XS has proper ithreads support, unlike JSON::XS. If you encounter any bugs with\nthread support please report them.\n\nFrom Version 4.00 - 4.19 you couldn't encode true with threads::shared magic.\n",
            "subsections": []
        },
        "BUGS": {
            "content": "While the goal of the Cpanel::JSON::XS module is to be correct, that unfortunately does not mean\nit's bug-free, only that the author thinks its design is bug-free. If you keep reporting bugs\nand tests they will be fixed swiftly, though.\n\nSince the JSON::XS author refuses to use a public bugtracker and prefers private emails, we use\nthe tracker at github, so you might want to report any issues twice. Once in private to MLEHMANN\nto be fixed in JSON::XS and one to our the public tracker. Issues fixed by JSON::XS with a new\nrelease will also be backported to Cpanel::JSON::XS and 5.6.2, as long as cPanel relies on 5.6.2\nand Cpanel::JSON::XS as our serializer of choice.\n\n<https://github.com/rurban/Cpanel-JSON-XS/issues>\n",
            "subsections": []
        },
        "LICENSE": {
            "content": "This module is available under the same licences as perl, the Artistic license and the GPL.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "The cpaneljsonxs command line utility for quick experiments.\n\nJSON, JSON::XS, JSON::MaybeXS, Mojo::JSON, Mojo::JSON::MaybeXS, JSON::SL, JSON::DWIW,\nJSON::YAJL, JSON::Any, Test::JSON, Locale::Wolowitz, <https://metacpan.org/search?q=JSON>\n\n<https://tools.ietf.org/html/rfc7159>\n\n<https://tools.ietf.org/html/rfc4627>\n",
            "subsections": []
        },
        "AUTHOR": {
            "content": "Reini Urban <rurban@cpan.org>\n\nMarc Lehmann <schmorp@schmorp.de>, http://home.schmorp.de/\n",
            "subsections": []
        },
        "MAINTAINER": {
            "content": "Reini Urban <rurban@cpan.org>\n",
            "subsections": []
        }
    },
    "summary": "Cpanel::JSON::XS - cPanel fork of JSON::XS, fast and correct serializing",
    "flags": [],
    "examples": [],
    "see_also": []
}