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perlapi

Perl 5 version 12.3 documentation
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perlapi

NAME

perlapi - autogenerated documentation for the perl public API

DESCRIPTION

This file contains the documentation of the perl public API generated by embed.pl, specifically a listing of functions, macros, flags, and variables that may be used by extension writers. The interfaces of any functions that are not listed here are subject to change without notice. For this reason, blindly using functions listed in proto.h is to be avoided when writing extensions.

Note that all Perl API global variables must be referenced with the PL_ prefix. Some macros are provided for compatibility with the older, unadorned names, but this support may be disabled in a future release.

Perl was originally written to handle US-ASCII only (that is characters whose ordinal numbers are in the range 0 - 127). And documentation and comments may still use the term ASCII, when sometimes in fact the entire range from 0 - 255 is meant.

Note that Perl can be compiled and run under EBCDIC (See perlebcdic) or ASCII. Most of the documentation (and even comments in the code) ignore the EBCDIC possibility. For almost all purposes the differences are transparent. As an example, under EBCDIC, instead of UTF-8, UTF-EBCDIC is used to encode Unicode strings, and so whenever this documentation refers to utf8 (and variants of that name, including in function names), it also (essentially transparently) means UTF-EBCDIC . But the ordinals of characters differ between ASCII, EBCDIC, and the UTF- encodings, and a string encoded in UTF-EBCDIC may occupy more bytes than in UTF-8.

Also, on some EBCDIC machines, functions that are documented as operating on US-ASCII (or Basic Latin in Unicode terminology) may in fact operate on all 256 characters in the EBCDIC range, not just the subset corresponding to US-ASCII.

The listing below is alphabetical, case insensitive.

"Gimme" Values

  • GIMME

    A backward-compatible version of GIMME_V which can only return G_SCALAR or G_ARRAY ; in a void context, it returns G_SCALAR . Deprecated. Use GIMME_V instead.

    1. U32 GIMME
  • GIMME_V

    The XSUB-writer's equivalent to Perl's wantarray. Returns G_VOID , G_SCALAR or G_ARRAY for void, scalar or list context, respectively.

    1. U32 GIMME_V
  • G_ARRAY

    Used to indicate list context. See GIMME_V , GIMME and perlcall.

  • G_DISCARD

    Indicates that arguments returned from a callback should be discarded. See perlcall.

  • G_EVAL

    Used to force a Perl eval wrapper around a callback. See perlcall.

  • G_NOARGS

    Indicates that no arguments are being sent to a callback. See perlcall.

  • G_SCALAR

    Used to indicate scalar context. See GIMME_V , GIMME , and perlcall.

  • G_VOID

    Used to indicate void context. See GIMME_V and perlcall.

Array Manipulation Functions

  • AvFILL

    Same as av_len() . Deprecated, use av_len() instead.

    1. int AvFILL(AV* av)
  • av_clear

    Clears an array, making it empty. Does not free the memory used by the array itself.

    1. void av_clear(AV *av)
  • av_create_and_push

    Push an SV onto the end of the array, creating the array if necessary. A small internal helper function to remove a commonly duplicated idiom.

    NOTE: this function is experimental and may change or be removed without notice.

    1. void av_create_and_push(AV **const avp, SV *const val)
  • av_create_and_unshift_one

    Unshifts an SV onto the beginning of the array, creating the array if necessary. A small internal helper function to remove a commonly duplicated idiom.

    NOTE: this function is experimental and may change or be removed without notice.

    1. SV** av_create_and_unshift_one(AV **const avp, SV *const val)
  • av_delete

    Deletes the element indexed by key from the array. Returns the deleted element. If flags equals G_DISCARD , the element is freed and null is returned.

    1. SV* av_delete(AV *av, I32 key, I32 flags)
  • av_exists

    Returns true if the element indexed by key has been initialized.

    This relies on the fact that uninitialized array elements are set to &PL_sv_undef .

    1. bool av_exists(AV *av, I32 key)
  • av_extend

    Pre-extend an array. The key is the index to which the array should be extended.

    1. void av_extend(AV *av, I32 key)
  • av_fetch

    Returns the SV at the specified index in the array. The key is the index. If lval is set then the fetch will be part of a store. Check that the return value is non-null before dereferencing it to a SV* .

    See Understanding the Magic of Tied Hashes and Arrays in perlguts for more information on how to use this function on tied arrays.

    1. SV** av_fetch(AV *av, I32 key, I32 lval)
  • av_fill

    Set the highest index in the array to the given number, equivalent to Perl's $#array = $fill; .

    The number of elements in the an array will be fill + 1 after av_fill() returns. If the array was previously shorter then the additional elements appended are set to PL_sv_undef . If the array was longer, then the excess elements are freed. av_fill(av, -1) is the same as av_clear(av) .

    1. void av_fill(AV *av, I32 fill)
  • av_len

    Returns the highest index in the array. The number of elements in the array is av_len(av) + 1 . Returns -1 if the array is empty.

    1. I32 av_len(AV *av)
  • av_make

    Creates a new AV and populates it with a list of SVs. The SVs are copied into the array, so they may be freed after the call to av_make. The new AV will have a reference count of 1.

    1. AV* av_make(I32 size, SV **strp)
  • av_pop

    Pops an SV off the end of the array. Returns &PL_sv_undef if the array is empty.

    1. SV* av_pop(AV *av)
  • av_push

    Pushes an SV onto the end of the array. The array will grow automatically to accommodate the addition. Like av_store , this takes ownership of one reference count.

    1. void av_push(AV *av, SV *val)
  • av_shift

    Shifts an SV off the beginning of the array. Returns &PL_sv_undef if the array is empty.

    1. SV* av_shift(AV *av)
  • av_store

    Stores an SV in an array. The array index is specified as key . The return value will be NULL if the operation failed or if the value did not need to be actually stored within the array (as in the case of tied arrays). Otherwise it can be dereferenced to get the original SV* . Note that the caller is responsible for suitably incrementing the reference count of val before the call, and decrementing it if the function returned NULL.

    See Understanding the Magic of Tied Hashes and Arrays in perlguts for more information on how to use this function on tied arrays.

    1. SV** av_store(AV *av, I32 key, SV *val)
  • av_undef

    Undefines the array. Frees the memory used by the array itself.

    1. void av_undef(AV *av)
  • av_unshift

    Unshift the given number of undef values onto the beginning of the array. The array will grow automatically to accommodate the addition. You must then use av_store to assign values to these new elements.

    1. void av_unshift(AV *av, I32 num)
  • get_av

    Returns the AV of the specified Perl array. flags are passed to gv_fetchpv . If GV_ADD is set and the Perl variable does not exist then it will be created. If flags is zero and the variable does not exist then NULL is returned.

    NOTE: the perl_ form of this function is deprecated.

    1. AV* get_av(const char *name, I32 flags)
  • newAV

    Creates a new AV. The reference count is set to 1.

    1. AV* newAV()
  • sortsv

    Sort an array. Here is an example:

    1. sortsv(AvARRAY(av), av_len(av)+1, Perl_sv_cmp_locale);

    Currently this always uses mergesort. See sortsv_flags for a more flexible routine.

    1. void sortsv(SV** array, size_t num_elts, SVCOMPARE_t cmp)
  • sortsv_flags

    Sort an array, with various options.

    1. void sortsv_flags(SV** array, size_t num_elts, SVCOMPARE_t cmp, U32 flags)

Callback Functions

  • call_argv

    Performs a callback to the specified Perl sub. See perlcall.

    NOTE: the perl_ form of this function is deprecated.

    1. I32 call_argv(const char* sub_name, I32 flags, char** argv)
  • call_method

    Performs a callback to the specified Perl method. The blessed object must be on the stack. See perlcall.

    NOTE: the perl_ form of this function is deprecated.

    1. I32 call_method(const char* methname, I32 flags)
  • call_pv

    Performs a callback to the specified Perl sub. See perlcall.

    NOTE: the perl_ form of this function is deprecated.

    1. I32 call_pv(const char* sub_name, I32 flags)
  • call_sv

    Performs a callback to the Perl sub whose name is in the SV. See perlcall.

    NOTE: the perl_ form of this function is deprecated.

    1. I32 call_sv(SV* sv, VOL I32 flags)
  • ENTER

    Opening bracket on a callback. See LEAVE and perlcall.

    1. ENTER;
  • eval_pv

    Tells Perl to eval the given string and return an SV* result.

    NOTE: the perl_ form of this function is deprecated.

    1. SV* eval_pv(const char* p, I32 croak_on_error)
  • eval_sv

    Tells Perl to eval the string in the SV.

    NOTE: the perl_ form of this function is deprecated.

    1. I32 eval_sv(SV* sv, I32 flags)
  • FREETMPS

    Closing bracket for temporaries on a callback. See SAVETMPS and perlcall.

    1. FREETMPS;
  • LEAVE

    Closing bracket on a callback. See ENTER and perlcall.

    1. LEAVE;
  • SAVETMPS

    Opening bracket for temporaries on a callback. See FREETMPS and perlcall.

    1. SAVETMPS;

Character classes

  • isALNUM

    Returns a boolean indicating whether the C char is a US-ASCII (Basic Latin) alphanumeric character (including underscore) or digit.

    1. bool isALNUM(char ch)
  • isALPHA

    Returns a boolean indicating whether the C char is a US-ASCII (Basic Latin) alphabetic character.

    1. bool isALPHA(char ch)
  • isDIGIT

    Returns a boolean indicating whether the C char is a US-ASCII (Basic Latin) digit.

    1. bool isDIGIT(char ch)
  • isLOWER

    Returns a boolean indicating whether the C char is a US-ASCII (Basic Latin) lowercase character.

    1. bool isLOWER(char ch)
  • isSPACE

    Returns a boolean indicating whether the C char is a US-ASCII (Basic Latin) whitespace.

    1. bool isSPACE(char ch)
  • isUPPER

    Returns a boolean indicating whether the C char is a US-ASCII (Basic Latin) uppercase character.

    1. bool isUPPER(char ch)
  • toLOWER

    Converts the specified character to lowercase. Characters outside the US-ASCII (Basic Latin) range are viewed as not having any case.

    1. char toLOWER(char ch)
  • toUPPER

    Converts the specified character to uppercase. Characters outside the US-ASCII (Basic Latin) range are viewed as not having any case.

    1. char toUPPER(char ch)

Cloning an interpreter

  • perl_clone

    Create and return a new interpreter by cloning the current one.

    perl_clone takes these flags as parameters:

    CLONEf_COPY_STACKS - is used to, well, copy the stacks also, without it we only clone the data and zero the stacks, with it we copy the stacks and the new perl interpreter is ready to run at the exact same point as the previous one. The pseudo-fork code uses COPY_STACKS while the threads->create doesn't.

    CLONEf_KEEP_PTR_TABLE perl_clone keeps a ptr_table with the pointer of the old variable as a key and the new variable as a value, this allows it to check if something has been cloned and not clone it again but rather just use the value and increase the refcount. If KEEP_PTR_TABLE is not set then perl_clone will kill the ptr_table using the function ptr_table_free(PL_ptr_table); PL_ptr_table = NULL; , reason to keep it around is if you want to dup some of your own variable who are outside the graph perl scans, example of this code is in threads.xs create

    CLONEf_CLONE_HOST This is a win32 thing, it is ignored on unix, it tells perls win32host code (which is c++) to clone itself, this is needed on win32 if you want to run two threads at the same time, if you just want to do some stuff in a separate perl interpreter and then throw it away and return to the original one, you don't need to do anything.

    1. PerlInterpreter* perl_clone(PerlInterpreter *proto_perl, UV flags)

CV Manipulation Functions

  • CvSTASH

    Returns the stash of the CV.

    1. HV* CvSTASH(CV* cv)
  • get_cv

    Uses strlen to get the length of name , then calls get_cvn_flags .

    NOTE: the perl_ form of this function is deprecated.

    1. CV* get_cv(const char* name, I32 flags)
  • get_cvn_flags

    Returns the CV of the specified Perl subroutine. flags are passed to gv_fetchpvn_flags . If GV_ADD is set and the Perl subroutine does not exist then it will be declared (which has the same effect as saying sub name; ). If GV_ADD is not set and the subroutine does not exist then NULL is returned.

    NOTE: the perl_ form of this function is deprecated.

    1. CV* get_cvn_flags(const char* name, STRLEN len, I32 flags)

Embedding Functions

  • cv_undef

    Clear out all the active components of a CV. This can happen either by an explicit undef &foo , or by the reference count going to zero. In the former case, we keep the CvOUTSIDE pointer, so that any anonymous children can still follow the full lexical scope chain.

    1. void cv_undef(CV* cv)
  • load_module

    Loads the module whose name is pointed to by the string part of name. Note that the actual module name, not its filename, should be given. Eg, "Foo::Bar" instead of "Foo/Bar.pm". flags can be any of PERL_LOADMOD_DENY, PERL_LOADMOD_NOIMPORT, or PERL_LOADMOD_IMPORT_OPS (or 0 for no flags). ver, if specified, provides version semantics similar to use Foo::Bar VERSION . The optional trailing SV* arguments can be used to specify arguments to the module's import() method, similar to use Foo::Bar VERSION LIST . They must be terminated with a final NULL pointer. Note that this list can only be omitted when the PERL_LOADMOD_NOIMPORT flag has been used. Otherwise at least a single NULL pointer to designate the default import list is required.

    1. void load_module(U32 flags, SV* name, SV* ver, ...)
  • nothreadhook

    Stub that provides thread hook for perl_destruct when there are no threads.

    1. int nothreadhook()
  • perl_alloc

    Allocates a new Perl interpreter. See perlembed.

    1. PerlInterpreter* perl_alloc()
  • perl_construct

    Initializes a new Perl interpreter. See perlembed.

    1. void perl_construct(PerlInterpreter *my_perl)
  • perl_destruct

    Shuts down a Perl interpreter. See perlembed.

    1. int perl_destruct(PerlInterpreter *my_perl)
  • perl_free

    Releases a Perl interpreter. See perlembed.

    1. void perl_free(PerlInterpreter *my_perl)
  • perl_parse

    Tells a Perl interpreter to parse a Perl script. See perlembed.

    1. int perl_parse(PerlInterpreter *my_perl, XSINIT_t xsinit, int argc, char** argv, char** env)
  • perl_run

    Tells a Perl interpreter to run. See perlembed.

    1. int perl_run(PerlInterpreter *my_perl)
  • require_pv

    Tells Perl to require the file named by the string argument. It is analogous to the Perl code eval "require '$file'" . It's even implemented that way; consider using load_module instead.

    NOTE: the perl_ form of this function is deprecated.

    1. void require_pv(const char* pv)

Functions in file dump.c

  • pv_display

    Similar to

    1. pv_escape(dsv,pv,cur,pvlim,PERL_PV_ESCAPE_QUOTE);

    except that an additional "\0" will be appended to the string when len > cur and pv[cur] is "\0".

    Note that the final string may be up to 7 chars longer than pvlim.

    1. char* pv_display(SV *dsv, const char *pv, STRLEN cur, STRLEN len, STRLEN pvlim)
  • pv_escape

    Escapes at most the first "count" chars of pv and puts the results into dsv such that the size of the escaped string will not exceed "max" chars and will not contain any incomplete escape sequences.

    If flags contains PERL_PV_ESCAPE_QUOTE then any double quotes in the string will also be escaped.

    Normally the SV will be cleared before the escaped string is prepared, but when PERL_PV_ESCAPE_NOCLEAR is set this will not occur.

    If PERL_PV_ESCAPE_UNI is set then the input string is treated as Unicode, if PERL_PV_ESCAPE_UNI_DETECT is set then the input string is scanned using is_utf8_string() to determine if it is Unicode.

    If PERL_PV_ESCAPE_ALL is set then all input chars will be output using \x01F1 style escapes, otherwise only chars above 255 will be escaped using this style, other non printable chars will use octal or common escaped patterns like \n . If PERL_PV_ESCAPE_NOBACKSLASH then all chars below 255 will be treated as printable and will be output as literals.

    If PERL_PV_ESCAPE_FIRSTCHAR is set then only the first char of the string will be escaped, regardles of max. If the string is utf8 and the chars value is >255 then it will be returned as a plain hex sequence. Thus the output will either be a single char, an octal escape sequence, a special escape like \n or a 3 or more digit hex value.

    If PERL_PV_ESCAPE_RE is set then the escape char used will be a '%' and not a '\\'. This is because regexes very often contain backslashed sequences, whereas '%' is not a particularly common character in patterns.

    Returns a pointer to the escaped text as held by dsv.

    1. char* pv_escape(SV *dsv, char const * const str, const STRLEN count, const STRLEN max, STRLEN * const escaped, const U32 flags)
  • pv_pretty

    Converts a string into something presentable, handling escaping via pv_escape() and supporting quoting and ellipses.

    If the PERL_PV_PRETTY_QUOTE flag is set then the result will be double quoted with any double quotes in the string escaped. Otherwise if the PERL_PV_PRETTY_LTGT flag is set then the result be wrapped in angle brackets.

    If the PERL_PV_PRETTY_ELLIPSES flag is set and not all characters in string were output then an ellipsis ... will be appended to the string. Note that this happens AFTER it has been quoted.

    If start_color is non-null then it will be inserted after the opening quote (if there is one) but before the escaped text. If end_color is non-null then it will be inserted after the escaped text but before any quotes or ellipses.

    Returns a pointer to the prettified text as held by dsv.

    1. char* pv_pretty(SV *dsv, char const * const str, const STRLEN count, const STRLEN max, char const * const start_color, char const * const end_color, const U32 flags)

Functions in file mathoms.c

  • gv_fetchmethod

    See gv_fetchmethod_autoload.

    1. GV* gv_fetchmethod(HV* stash, const char* name)
  • pack_cat

    The engine implementing pack() Perl function. Note: parameters next_in_list and flags are not used. This call should not be used; use packlist instead.

    1. void pack_cat(SV *cat, const char *pat, const char *patend, SV **beglist, SV **endlist, SV ***next_in_list, U32 flags)
  • sv_2pvbyte_nolen

    Return a pointer to the byte-encoded representation of the SV. May cause the SV to be downgraded from UTF-8 as a side-effect.

    Usually accessed via the SvPVbyte_nolen macro.

    1. char* sv_2pvbyte_nolen(SV* sv)
  • sv_2pvutf8_nolen

    Return a pointer to the UTF-8-encoded representation of the SV. May cause the SV to be upgraded to UTF-8 as a side-effect.

    Usually accessed via the SvPVutf8_nolen macro.

    1. char* sv_2pvutf8_nolen(SV* sv)
  • sv_2pv_nolen

    Like sv_2pv() , but doesn't return the length too. You should usually use the macro wrapper SvPV_nolen(sv) instead. char* sv_2pv_nolen(SV* sv)

  • sv_catpvn_mg

    Like sv_catpvn , but also handles 'set' magic.

    1. void sv_catpvn_mg(SV *sv, const char *ptr, STRLEN len)
  • sv_catsv_mg

    Like sv_catsv , but also handles 'set' magic.

    1. void sv_catsv_mg(SV *dsv, SV *ssv)
  • sv_force_normal

    Undo various types of fakery on an SV: if the PV is a shared string, make a private copy; if we're a ref, stop refing; if we're a glob, downgrade to an xpvmg. See also sv_force_normal_flags .

    1. void sv_force_normal(SV *sv)
  • sv_iv

    A private implementation of the SvIVx macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    1. IV sv_iv(SV* sv)
  • sv_nolocking

    Dummy routine which "locks" an SV when there is no locking module present. Exists to avoid test for a NULL function pointer and because it could potentially warn under some level of strict-ness.

    "Superseded" by sv_nosharing().

    1. void sv_nolocking(SV *sv)
  • sv_nounlocking

    Dummy routine which "unlocks" an SV when there is no locking module present. Exists to avoid test for a NULL function pointer and because it could potentially warn under some level of strict-ness.

    "Superseded" by sv_nosharing().

    1. void sv_nounlocking(SV *sv)
  • sv_nv

    A private implementation of the SvNVx macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    1. NV sv_nv(SV* sv)
  • sv_pv

    Use the SvPV_nolen macro instead

    1. char* sv_pv(SV *sv)
  • sv_pvbyte

    Use SvPVbyte_nolen instead.

    1. char* sv_pvbyte(SV *sv)
  • sv_pvbyten

    A private implementation of the SvPVbyte macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    1. char* sv_pvbyten(SV *sv, STRLEN *lp)
  • sv_pvn

    A private implementation of the SvPV macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    1. char* sv_pvn(SV *sv, STRLEN *lp)
  • sv_pvutf8

    Use the SvPVutf8_nolen macro instead

    1. char* sv_pvutf8(SV *sv)
  • sv_pvutf8n

    A private implementation of the SvPVutf8 macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    1. char* sv_pvutf8n(SV *sv, STRLEN *lp)
  • sv_taint

    Taint an SV. Use SvTAINTED_on instead. void sv_taint(SV* sv)

  • sv_unref

    Unsets the RV status of the SV, and decrements the reference count of whatever was being referenced by the RV. This can almost be thought of as a reversal of newSVrv . This is sv_unref_flags with the flag being zero. See SvROK_off .

    1. void sv_unref(SV* sv)
  • sv_usepvn

    Tells an SV to use ptr to find its string value. Implemented by calling sv_usepvn_flags with flags of 0, hence does not handle 'set' magic. See sv_usepvn_flags .

    1. void sv_usepvn(SV* sv, char* ptr, STRLEN len)
  • sv_usepvn_mg

    Like sv_usepvn , but also handles 'set' magic.

    1. void sv_usepvn_mg(SV *sv, char *ptr, STRLEN len)
  • sv_uv

    A private implementation of the SvUVx macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    1. UV sv_uv(SV* sv)
  • unpack_str

    The engine implementing unpack() Perl function. Note: parameters strbeg, new_s and ocnt are not used. This call should not be used, use unpackstring instead.

    1. I32 unpack_str(const char *pat, const char *patend, const char *s, const char *strbeg, const char *strend, char **new_s, I32 ocnt, U32 flags)

Functions in file perl.h

  • PERL_SYS_INIT

    Provides system-specific tune up of the C runtime environment necessary to run Perl interpreters. This should be called only once, before creating any Perl interpreters.

    1. void PERL_SYS_INIT(int argc, char** argv)
  • PERL_SYS_INIT3

    Provides system-specific tune up of the C runtime environment necessary to run Perl interpreters. This should be called only once, before creating any Perl interpreters.

    1. void PERL_SYS_INIT3(int argc, char** argv, char** env)
  • PERL_SYS_TERM

    Provides system-specific clean up of the C runtime environment after running Perl interpreters. This should be called only once, after freeing any remaining Perl interpreters.

    1. void PERL_SYS_TERM()

Functions in file pp_ctl.c

  • find_runcv

    Locate the CV corresponding to the currently executing sub or eval. If db_seqp is non_null, skip CVs that are in the DB package and populate *db_seqp with the cop sequence number at the point that the DB:: code was entered. (allows debuggers to eval in the scope of the breakpoint rather than in the scope of the debugger itself).

    1. CV* find_runcv(U32 *db_seqp)

Functions in file pp_pack.c

  • packlist

    The engine implementing pack() Perl function.

    1. void packlist(SV *cat, const char *pat, const char *patend, SV **beglist, SV **endlist)
  • unpackstring

    The engine implementing unpack() Perl function. unpackstring puts the extracted list items on the stack and returns the number of elements. Issue PUTBACK before and SPAGAIN after the call to this function.

    1. I32 unpackstring(const char *pat, const char *patend, const char *s, const char *strend, U32 flags)

Functions in file pp_sys.c

  • setdefout

    Sets PL_defoutgv, the default file handle for output, to the passed in typeglob. As PL_defoutgv "owns" a reference on its typeglob, the reference count of the passed in typeglob is increased by one, and the reference count of the typeglob that PL_defoutgv points to is decreased by one.

    1. void setdefout(GV* gv)

Global Variables

  • PL_keyword_plugin

    Function pointer, pointing at a function used to handle extended keywords. The function should be declared as

    1. int keyword_plugin_function(pTHX_
    2. char *keyword_ptr, STRLEN keyword_len,
    3. OP **op_ptr)

    The function is called from the tokeniser, whenever a possible keyword is seen. keyword_ptr points at the word in the parser's input buffer, and keyword_len gives its length; it is not null-terminated. The function is expected to examine the word, and possibly other state such as %^H, to decide whether it wants to handle it as an extended keyword. If it does not, the function should return KEYWORD_PLUGIN_DECLINE , and the normal parser process will continue.

    If the function wants to handle the keyword, it first must parse anything following the keyword that is part of the syntax introduced by the keyword. See Lexer interface for details.

    When a keyword is being handled, the plugin function must build a tree of OP structures, representing the code that was parsed. The root of the tree must be stored in *op_ptr . The function then returns a contant indicating the syntactic role of the construct that it has parsed: KEYWORD_PLUGIN_STMT if it is a complete statement, or KEYWORD_PLUGIN_EXPR if it is an expression. Note that a statement construct cannot be used inside an expression (except via do BLOCK and similar), and an expression is not a complete statement (it requires at least a terminating semicolon).

    When a keyword is handled, the plugin function may also have (compile-time) side effects. It may modify %^H , define functions, and so on. Typically, if side effects are the main purpose of a handler, it does not wish to generate any ops to be included in the normal compilation. In this case it is still required to supply an op tree, but it suffices to generate a single null op.

    That's how the *PL_keyword_plugin function needs to behave overall. Conventionally, however, one does not completely replace the existing handler function. Instead, take a copy of PL_keyword_plugin before assigning your own function pointer to it. Your handler function should look for keywords that it is interested in and handle those. Where it is not interested, it should call the saved plugin function, passing on the arguments it received. Thus PL_keyword_plugin actually points at a chain of handler functions, all of which have an opportunity to handle keywords, and only the last function in the chain (built into the Perl core) will normally return KEYWORD_PLUGIN_DECLINE .

    NOTE: this function is experimental and may change or be removed without notice.

GV Functions

  • GvSV

    Return the SV from the GV.

    1. SV* GvSV(GV* gv)
  • gv_const_sv

    If gv is a typeglob whose subroutine entry is a constant sub eligible for inlining, or gv is a placeholder reference that would be promoted to such a typeglob, then returns the value returned by the sub. Otherwise, returns NULL.

    1. SV* gv_const_sv(GV* gv)
  • gv_fetchmeth

    Returns the glob with the given name and a defined subroutine or NULL . The glob lives in the given stash , or in the stashes accessible via @ISA and UNIVERSAL::.

    The argument level should be either 0 or -1. If level==0 , as a side-effect creates a glob with the given name in the given stash which in the case of success contains an alias for the subroutine, and sets up caching info for this glob.

    This function grants "SUPER" token as a postfix of the stash name. The GV returned from gv_fetchmeth may be a method cache entry, which is not visible to Perl code. So when calling call_sv , you should not use the GV directly; instead, you should use the method's CV, which can be obtained from the GV with the GvCV macro.

    1. GV* gv_fetchmeth(HV* stash, const char* name, STRLEN len, I32 level)
  • gv_fetchmethod_autoload

    Returns the glob which contains the subroutine to call to invoke the method on the stash . In fact in the presence of autoloading this may be the glob for "AUTOLOAD". In this case the corresponding variable $AUTOLOAD is already setup.

    The third parameter of gv_fetchmethod_autoload determines whether AUTOLOAD lookup is performed if the given method is not present: non-zero means yes, look for AUTOLOAD; zero means no, don't look for AUTOLOAD. Calling gv_fetchmethod is equivalent to calling gv_fetchmethod_autoload with a non-zero autoload parameter.

    These functions grant "SUPER" token as a prefix of the method name. Note that if you want to keep the returned glob for a long time, you need to check for it being "AUTOLOAD", since at the later time the call may load a different subroutine due to $AUTOLOAD changing its value. Use the glob created via a side effect to do this.

    These functions have the same side-effects and as gv_fetchmeth with level==0 . name should be writable if contains ':' or ' ''. The warning against passing the GV returned by gv_fetchmeth to call_sv apply equally to these functions.

    1. GV* gv_fetchmethod_autoload(HV* stash, const char* name, I32 autoload)
  • gv_fetchmeth_autoload

    Same as gv_fetchmeth(), but looks for autoloaded subroutines too. Returns a glob for the subroutine.

    For an autoloaded subroutine without a GV, will create a GV even if level < 0 . For an autoloaded subroutine without a stub, GvCV() of the result may be zero.

    1. GV* gv_fetchmeth_autoload(HV* stash, const char* name, STRLEN len, I32 level)
  • gv_stashpv

    Returns a pointer to the stash for a specified package. Uses strlen to determine the length of name , then calls gv_stashpvn() .

    1. HV* gv_stashpv(const char* name, I32 flags)
  • gv_stashpvn

    Returns a pointer to the stash for a specified package. The namelen parameter indicates the length of the name , in bytes. flags is passed to gv_fetchpvn_flags() , so if set to GV_ADD then the package will be created if it does not already exist. If the package does not exist and flags is 0 (or any other setting that does not create packages) then NULL is returned.

    1. HV* gv_stashpvn(const char* name, U32 namelen, I32 flags)
  • gv_stashpvs

    Like gv_stashpvn , but takes a literal string instead of a string/length pair.

    1. HV* gv_stashpvs(const char* name, I32 create)
  • gv_stashsv

    Returns a pointer to the stash for a specified package. See gv_stashpvn .

    1. HV* gv_stashsv(SV* sv, I32 flags)

Handy Values

  • Nullav

    Null AV pointer.

    (deprecated - use (AV *)NULL instead)

  • Nullch

    Null character pointer. (No longer available when PERL_CORE is defined.)

  • Nullcv

    Null CV pointer.

    (deprecated - use (CV *)NULL instead)

  • Nullhv

    Null HV pointer.

    (deprecated - use (HV *)NULL instead)

  • Nullsv

    Null SV pointer. (No longer available when PERL_CORE is defined.)

Hash Manipulation Functions

  • get_hv

    Returns the HV of the specified Perl hash. flags are passed to gv_fetchpv . If GV_ADD is set and the Perl variable does not exist then it will be created. If flags is zero and the variable does not exist then NULL is returned.

    NOTE: the perl_ form of this function is deprecated.

    1. HV* get_hv(const char *name, I32 flags)
  • HEf_SVKEY

    This flag, used in the length slot of hash entries and magic structures, specifies the structure contains an SV* pointer where a char* pointer is to be expected. (For information only--not to be used).

  • HeHASH

    Returns the computed hash stored in the hash entry.

    1. U32 HeHASH(HE* he)
  • HeKEY

    Returns the actual pointer stored in the key slot of the hash entry. The pointer may be either char* or SV* , depending on the value of HeKLEN() . Can be assigned to. The HePV() or HeSVKEY() macros are usually preferable for finding the value of a key.

    1. void* HeKEY(HE* he)
  • HeKLEN

    If this is negative, and amounts to HEf_SVKEY , it indicates the entry holds an SV* key. Otherwise, holds the actual length of the key. Can be assigned to. The HePV() macro is usually preferable for finding key lengths.

    1. STRLEN HeKLEN(HE* he)
  • HePV

    Returns the key slot of the hash entry as a char* value, doing any necessary dereferencing of possibly SV* keys. The length of the string is placed in len (this is a macro, so do not use &len ). If you do not care about what the length of the key is, you may use the global variable PL_na , though this is rather less efficient than using a local variable. Remember though, that hash keys in perl are free to contain embedded nulls, so using strlen() or similar is not a good way to find the length of hash keys. This is very similar to the SvPV() macro described elsewhere in this document. See also HeUTF8 .

    If you are using HePV to get values to pass to newSVpvn() to create a new SV, you should consider using newSVhek(HeKEY_hek(he)) as it is more efficient.

    1. char* HePV(HE* he, STRLEN len)
  • HeSVKEY

    Returns the key as an SV* , or NULL if the hash entry does not contain an SV* key.

    1. SV* HeSVKEY(HE* he)
  • HeSVKEY_force

    Returns the key as an SV* . Will create and return a temporary mortal SV* if the hash entry contains only a char* key.

    1. SV* HeSVKEY_force(HE* he)
  • HeSVKEY_set

    Sets the key to a given SV* , taking care to set the appropriate flags to indicate the presence of an SV* key, and returns the same SV* .

    1. SV* HeSVKEY_set(HE* he, SV* sv)
  • HeUTF8

    Returns whether the char * value returned by HePV is encoded in UTF-8, doing any necessary dereferencing of possibly SV* keys. The value returned will be 0 or non-0, not necessarily 1 (or even a value with any low bits set), so do not blindly assign this to a bool variable, as bool may be a typedef for char .

    1. char* HeUTF8(HE* he)
  • HeVAL

    Returns the value slot (type SV* ) stored in the hash entry.

    1. SV* HeVAL(HE* he)
  • HvNAME

    Returns the package name of a stash, or NULL if stash isn't a stash. See SvSTASH , CvSTASH .

    1. char* HvNAME(HV* stash)
  • hv_assert

    Check that a hash is in an internally consistent state.

    1. void hv_assert(HV *hv)
  • hv_clear

    Clears a hash, making it empty.

    1. void hv_clear(HV *hv)
  • hv_clear_placeholders

    Clears any placeholders from a hash. If a restricted hash has any of its keys marked as readonly and the key is subsequently deleted, the key is not actually deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags it so it will be ignored by future operations such as iterating over the hash, but will still allow the hash to have a value reassigned to the key at some future point. This function clears any such placeholder keys from the hash. See Hash::Util::lock_keys() for an example of its use.

    1. void hv_clear_placeholders(HV *hv)
  • hv_delete

    Deletes a key/value pair in the hash. The value SV is removed from the hash and returned to the caller. The klen is the length of the key. The flags value will normally be zero; if set to G_DISCARD then NULL will be returned.

    1. SV* hv_delete(HV *hv, const char *key, I32 klen, I32 flags)
  • hv_delete_ent

    Deletes a key/value pair in the hash. The value SV is removed from the hash and returned to the caller. The flags value will normally be zero; if set to G_DISCARD then NULL will be returned. hash can be a valid precomputed hash value, or 0 to ask for it to be computed.

    1. SV* hv_delete_ent(HV *hv, SV *keysv, I32 flags, U32 hash)
  • hv_exists

    Returns a boolean indicating whether the specified hash key exists. The klen is the length of the key.

    1. bool hv_exists(HV *hv, const char *key, I32 klen)
  • hv_exists_ent

    Returns a boolean indicating whether the specified hash key exists. hash can be a valid precomputed hash value, or 0 to ask for it to be computed.

    1. bool hv_exists_ent(HV *hv, SV *keysv, U32 hash)
  • hv_fetch

    Returns the SV which corresponds to the specified key in the hash. The klen is the length of the key. If lval is set then the fetch will be part of a store. Check that the return value is non-null before dereferencing it to an SV* .

    See Understanding the Magic of Tied Hashes and Arrays in perlguts for more information on how to use this function on tied hashes.

    1. SV** hv_fetch(HV *hv, const char *key, I32 klen, I32 lval)
  • hv_fetchs

    Like hv_fetch , but takes a literal string instead of a string/length pair.

    1. SV** hv_fetchs(HV* tb, const char* key, I32 lval)
  • hv_fetch_ent

    Returns the hash entry which corresponds to the specified key in the hash. hash must be a valid precomputed hash number for the given key , or 0 if you want the function to compute it. IF lval is set then the fetch will be part of a store. Make sure the return value is non-null before accessing it. The return value when tb is a tied hash is a pointer to a static location, so be sure to make a copy of the structure if you need to store it somewhere.

    See Understanding the Magic of Tied Hashes and Arrays in perlguts for more information on how to use this function on tied hashes.

    1. HE* hv_fetch_ent(HV *hv, SV *keysv, I32 lval, U32 hash)
  • hv_iterinit

    Prepares a starting point to traverse a hash table. Returns the number of keys in the hash (i.e. the same as HvKEYS(tb) ). The return value is currently only meaningful for hashes without tie magic.

    NOTE: Before version 5.004_65, hv_iterinit used to return the number of hash buckets that happen to be in use. If you still need that esoteric value, you can get it through the macro HvFILL(tb) .

    1. I32 hv_iterinit(HV *hv)
  • hv_iterkey

    Returns the key from the current position of the hash iterator. See hv_iterinit .

    1. char* hv_iterkey(HE* entry, I32* retlen)
  • hv_iterkeysv

    Returns the key as an SV* from the current position of the hash iterator. The return value will always be a mortal copy of the key. Also see hv_iterinit .

    1. SV* hv_iterkeysv(HE* entry)
  • hv_iternext

    Returns entries from a hash iterator. See hv_iterinit .

    You may call hv_delete or hv_delete_ent on the hash entry that the iterator currently points to, without losing your place or invalidating your iterator. Note that in this case the current entry is deleted from the hash with your iterator holding the last reference to it. Your iterator is flagged to free the entry on the next call to hv_iternext , so you must not discard your iterator immediately else the entry will leak - call hv_iternext to trigger the resource deallocation.

    1. HE* hv_iternext(HV *hv)
  • hv_iternextsv

    Performs an hv_iternext , hv_iterkey , and hv_iterval in one operation.

    1. SV* hv_iternextsv(HV *hv, char **key, I32 *retlen)
  • hv_iternext_flags

    Returns entries from a hash iterator. See hv_iterinit and hv_iternext . The flags value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is set the placeholders keys (for restricted hashes) will be returned in addition to normal keys. By default placeholders are automatically skipped over. Currently a placeholder is implemented with a value that is &Perl_sv_placeholder . Note that the implementation of placeholders and restricted hashes may change, and the implementation currently is insufficiently abstracted for any change to be tidy.

    NOTE: this function is experimental and may change or be removed without notice.

    1. HE* hv_iternext_flags(HV *hv, I32 flags)
  • hv_iterval

    Returns the value from the current position of the hash iterator. See hv_iterkey .

    1. SV* hv_iterval(HV *hv, HE *entry)
  • hv_magic

    Adds magic to a hash. See sv_magic .

    1. void hv_magic(HV *hv, GV *gv, int how)
  • hv_scalar

    Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.

    1. SV* hv_scalar(HV *hv)
  • hv_store

    Stores an SV in a hash. The hash key is specified as key and klen is the length of the key. The hash parameter is the precomputed hash value; if it is zero then Perl will compute it. The return value will be NULL if the operation failed or if the value did not need to be actually stored within the hash (as in the case of tied hashes). Otherwise it can be dereferenced to get the original SV* . Note that the caller is responsible for suitably incrementing the reference count of val before the call, and decrementing it if the function returned NULL. Effectively a successful hv_store takes ownership of one reference to val . This is usually what you want; a newly created SV has a reference count of one, so if all your code does is create SVs then store them in a hash, hv_store will own the only reference to the new SV, and your code doesn't need to do anything further to tidy up. hv_store is not implemented as a call to hv_store_ent, and does not create a temporary SV for the key, so if your key data is not already in SV form then use hv_store in preference to hv_store_ent.

    See Understanding the Magic of Tied Hashes and Arrays in perlguts for more information on how to use this function on tied hashes.

    1. SV** hv_store(HV *hv, const char *key, I32 klen, SV *val, U32 hash)
  • hv_stores

    Like hv_store , but takes a literal string instead of a string/length pair and omits the hash parameter.

    1. SV** hv_stores(HV* tb, const char* key, NULLOK SV* val)
  • hv_store_ent

    Stores val in a hash. The hash key is specified as key . The hash parameter is the precomputed hash value; if it is zero then Perl will compute it. The return value is the new hash entry so created. It will be NULL if the operation failed or if the value did not need to be actually stored within the hash (as in the case of tied hashes). Otherwise the contents of the return value can be accessed using the He? macros described here. Note that the caller is responsible for suitably incrementing the reference count of val before the call, and decrementing it if the function returned NULL. Effectively a successful hv_store_ent takes ownership of one reference to val . This is usually what you want; a newly created SV has a reference count of one, so if all your code does is create SVs then store them in a hash, hv_store will own the only reference to the new SV, and your code doesn't need to do anything further to tidy up. Note that hv_store_ent only reads the key ; unlike val it does not take ownership of it, so maintaining the correct reference count on key is entirely the caller's responsibility. hv_store is not implemented as a call to hv_store_ent, and does not create a temporary SV for the key, so if your key data is not already in SV form then use hv_store in preference to hv_store_ent.

    See Understanding the Magic of Tied Hashes and Arrays in perlguts for more information on how to use this function on tied hashes.

    1. HE* hv_store_ent(HV *hv, SV *key, SV *val, U32 hash)
  • hv_undef

    Undefines the hash.

    1. void hv_undef(HV *hv)
  • newHV

    Creates a new HV. The reference count is set to 1.

    1. HV* newHV()

Lexer interface

  • lex_bufutf8

    Indicates whether the octets in the lexer buffer (PL_parser->linestr) should be interpreted as the UTF-8 encoding of Unicode characters. If not, they should be interpreted as Latin-1 characters. This is analogous to the SvUTF8 flag for scalars.

    In UTF-8 mode, it is not guaranteed that the lexer buffer actually contains valid UTF-8. Lexing code must be robust in the face of invalid encoding.

    The actual SvUTF8 flag of the PL_parser->linestr scalar is significant, but not the whole story regarding the input character encoding. Normally, when a file is being read, the scalar contains octets and its SvUTF8 flag is off, but the octets should be interpreted as UTF-8 if the use utf8 pragma is in effect. During a string eval, however, the scalar may have the SvUTF8 flag on, and in this case its octets should be interpreted as UTF-8 unless the use bytes pragma is in effect. This logic may change in the future; use this function instead of implementing the logic yourself.

    NOTE: this function is experimental and may change or be removed without notice.

    1. bool lex_bufutf8()
  • lex_discard_to

    Discards the first part of the PL_parser->linestr buffer, up to ptr. The remaining content of the buffer will be moved, and all pointers into the buffer updated appropriately. ptr must not be later in the buffer than the position of PL_parser->bufptr: it is not permitted to discard text that has yet to be lexed.

    Normally it is not necessarily to do this directly, because it suffices to use the implicit discarding behaviour of lex_next_chunk and things based on it. However, if a token stretches across multiple lines, and the lexing code has kept multiple lines of text in the buffer fof that purpose, then after completion of the token it would be wise to explicitly discard the now-unneeded earlier lines, to avoid future multi-line tokens growing the buffer without bound.

    NOTE: this function is experimental and may change or be removed without notice.

    1. void lex_discard_to(char *ptr)
  • lex_grow_linestr

    Reallocates the lexer buffer (PL_parser->linestr) to accommodate at least len octets (including terminating NUL). Returns a pointer to the reallocated buffer. This is necessary before making any direct modification of the buffer that would increase its length. lex_stuff_pvn provides a more convenient way to insert text into the buffer.

    Do not use SvGROW or sv_grow directly on PL_parser->linestr ; this function updates all of the lexer's variables that point directly into the buffer.

    NOTE: this function is experimental and may change or be removed without notice.

    1. char * lex_grow_linestr(STRLEN len)
  • lex_next_chunk

    Reads in the next chunk of text to be lexed, appending it to PL_parser->linestr. This should be called when lexing code has looked to the end of the current chunk and wants to know more. It is usual, but not necessary, for lexing to have consumed the entirety of the current chunk at this time.

    If PL_parser->bufptr is pointing to the very end of the current chunk (i.e., the current chunk has been entirely consumed), normally the current chunk will be discarded at the same time that the new chunk is read in. If flags includes LEX_KEEP_PREVIOUS , the current chunk will not be discarded. If the current chunk has not been entirely consumed, then it will not be discarded regardless of the flag.

    Returns true if some new text was added to the buffer, or false if the buffer has reached the end of the input text.

    NOTE: this function is experimental and may change or be removed without notice.

    1. bool lex_next_chunk(U32 flags)
  • lex_peek_unichar

    Looks ahead one (Unicode) character in the text currently being lexed. Returns the codepoint (unsigned integer value) of the next character, or -1 if lexing has reached the end of the input text. To consume the peeked character, use lex_read_unichar.

    If the next character is in (or extends into) the next chunk of input text, the next chunk will be read in. Normally the current chunk will be discarded at the same time, but if flags includes LEX_KEEP_PREVIOUS then the current chunk will not be discarded.

    If the input is being interpreted as UTF-8 and a UTF-8 encoding error is encountered, an exception is generated.

    NOTE: this function is experimental and may change or be removed without notice.

    1. I32 lex_peek_unichar(U32 flags)
  • lex_read_space

    Reads optional spaces, in Perl style, in the text currently being lexed. The spaces may include ordinary whitespace characters and Perl-style comments. #line directives are processed if encountered. PL_parser->bufptr is moved past the spaces, so that it points at a non-space character (or the end of the input text).

    If spaces extend into the next chunk of input text, the next chunk will be read in. Normally the current chunk will be discarded at the same time, but if flags includes LEX_KEEP_PREVIOUS then the current chunk will not be discarded.

    NOTE: this function is experimental and may change or be removed without notice.

    1. void lex_read_space(U32 flags)
  • lex_read_to

    Consume text in the lexer buffer, from PL_parser->bufptr up to ptr. This advances PL_parser->bufptr to match ptr, performing the correct bookkeeping whenever a newline character is passed. This is the normal way to consume lexed text.

    Interpretation of the buffer's octets can be abstracted out by using the slightly higher-level functions lex_peek_unichar and lex_read_unichar.

    NOTE: this function is experimental and may change or be removed without notice.

    1. void lex_read_to(char *ptr)
  • lex_read_unichar

    Reads the next (Unicode) character in the text currently being lexed. Returns the codepoint (unsigned integer value) of the character read, and moves PL_parser->bufptr past the character, or returns -1 if lexing has reached the end of the input text. To non-destructively examine the next character, use lex_peek_unichar instead.

    If the next character is in (or extends into) the next chunk of input text, the next chunk will be read in. Normally the current chunk will be discarded at the same time, but if flags includes LEX_KEEP_PREVIOUS then the current chunk will not be discarded.

    If the input is being interpreted as UTF-8 and a UTF-8 encoding error is encountered, an exception is generated.

    NOTE: this function is experimental and may change or be removed without notice.

    1. I32 lex_read_unichar(U32 flags)
  • lex_stuff_pvn

    Insert characters into the lexer buffer (PL_parser->linestr), immediately after the current lexing point (PL_parser->bufptr), reallocating the buffer if necessary. This means that lexing code that runs later will see the characters as if they had appeared in the input. It is not recommended to do this as part of normal parsing, and most uses of this facility run the risk of the inserted characters being interpreted in an unintended manner.

    The string to be inserted is represented by len octets starting at pv. These octets are interpreted as either UTF-8 or Latin-1, according to whether the LEX_STUFF_UTF8 flag is set in flags. The characters are recoded for the lexer buffer, according to how the buffer is currently being interpreted (lex_bufutf8). If a string to be interpreted is available as a Perl scalar, the lex_stuff_sv function is more convenient.

    NOTE: this function is experimental and may change or be removed without notice.

    1. void lex_stuff_pvn(char *pv, STRLEN len, U32 flags)
  • lex_stuff_sv

    Insert characters into the lexer buffer (PL_parser->linestr), immediately after the current lexing point (PL_parser->bufptr), reallocating the buffer if necessary. This means that lexing code that runs later will see the characters as if they had appeared in the input. It is not recommended to do this as part of normal parsing, and most uses of this facility run the risk of the inserted characters being interpreted in an unintended manner.

    The string to be inserted is the string value of sv. The characters are recoded for the lexer buffer, according to how the buffer is currently being interpreted (lex_bufutf8). If a string to be interpreted is not already a Perl scalar, the lex_stuff_pvn function avoids the need to construct a scalar.

    NOTE: this function is experimental and may change or be removed without notice.

    1. void lex_stuff_sv(SV *sv, U32 flags)
  • lex_unstuff

    Discards text about to be lexed, from PL_parser->bufptr up to ptr. Text following ptr will be moved, and the buffer shortened. This hides the discarded text from any lexing code that runs later, as if the text had never appeared.

    This is not the normal way to consume lexed text. For that, use lex_read_to.

    NOTE: this function is experimental and may change or be removed without notice.

    1. void lex_unstuff(char *ptr)
  • PL_parser

    Pointer to a structure encapsulating the state of the parsing operation currently in progress. The pointer can be locally changed to perform a nested parse without interfering with the state of an outer parse. Individual members of PL_parser have their own documentation.

  • PL_parser->bufend

    Direct pointer to the end of the chunk of text currently being lexed, the end of the lexer buffer. This is equal to SvPVX(PL_parser->linestr) + SvCUR(PL_parser->linestr) . A NUL character (zero octet) is always located at the end of the buffer, and does not count as part of the buffer's contents.

    NOTE: this function is experimental and may change or be removed without notice.

  • PL_parser->bufptr

    Points to the current position of lexing inside the lexer buffer. Characters around this point may be freely examined, within the range delimited by SvPVX(PL_parser->linestr) and PL_parser->bufend. The octets of the buffer may be intended to be interpreted as either UTF-8 or Latin-1, as indicated by lex_bufutf8.

    Lexing code (whether in the Perl core or not) moves this pointer past the characters that it consumes. It is also expected to perform some bookkeeping whenever a newline character is consumed. This movement can be more conveniently performed by the function lex_read_to, which handles newlines appropriately.

    Interpretation of the buffer's octets can be abstracted out by using the slightly higher-level functions lex_peek_unichar and lex_read_unichar.

    NOTE: this function is experimental and may change or be removed without notice.

  • PL_parser->linestart

    Points to the start of the current line inside the lexer buffer. This is useful for indicating at which column an error occurred, and not much else. This must be updated by any lexing code that consumes a newline; the function lex_read_to handles this detail.

    NOTE: this function is experimental and may change or be removed without notice.

  • PL_parser->linestr

    Buffer scalar containing the chunk currently under consideration of the text currently being lexed. This is always a plain string scalar (for which SvPOK is true). It is not intended to be used as a scalar by normal scalar means; instead refer to the buffer directly by the pointer variables described below.

    The lexer maintains various char* pointers to things in the PL_parser->linestr buffer. If PL_parser->linestr is ever reallocated, all of these pointers must be updated. Don't attempt to do this manually, but rather use lex_grow_linestr if you need to reallocate the buffer.

    The content of the text chunk in the buffer is commonly exactly one complete line of input, up to and including a newline terminator, but there are situations where it is otherwise. The octets of the buffer may be intended to be interpreted as either UTF-8 or Latin-1. The function lex_bufutf8 tells you which. Do not use the SvUTF8 flag on this scalar, which may disagree with it.

    For direct examination of the buffer, the variable PL_parser->bufend points to the end of the buffer. The current lexing position is pointed to by PL_parser->bufptr. Direct use of these pointers is usually preferable to examination of the scalar through normal scalar means.

    NOTE: this function is experimental and may change or be removed without notice.

Magical Functions

  • mg_clear

    Clear something magical that the SV represents. See sv_magic .

    1. int mg_clear(SV* sv)
  • mg_copy

    Copies the magic from one SV to another. See sv_magic .

    1. int mg_copy(SV *sv, SV *nsv, const char *key, I32 klen)
  • mg_find

    Finds the magic pointer for type matching the SV. See sv_magic .

    1. MAGIC* mg_find(const SV* sv, int type)
  • mg_free

    Free any magic storage used by the SV. See sv_magic .

    1. int mg_free(SV* sv)
  • mg_get

    Do magic after a value is retrieved from the SV. See sv_magic .

    1. int mg_get(SV* sv)
  • mg_length

    Report on the SV's length. See sv_magic .

    1. U32 mg_length(SV* sv)
  • mg_magical

    Turns on the magical status of an SV. See sv_magic .

    1. void mg_magical(SV* sv)
  • mg_set

    Do magic after a value is assigned to the SV. See sv_magic .

    1. int mg_set(SV* sv)
  • SvGETMAGIC

    Invokes mg_get on an SV if it has 'get' magic. This macro evaluates its argument more than once.

    1. void SvGETMAGIC(SV* sv)
  • SvLOCK

    Arranges for a mutual exclusion lock to be obtained on sv if a suitable module has been loaded.

    1. void SvLOCK(SV* sv)
  • SvSETMAGIC

    Invokes mg_set on an SV if it has 'set' magic. This macro evaluates its argument more than once.

    1. void SvSETMAGIC(SV* sv)
  • SvSetMagicSV

    Like SvSetSV , but does any set magic required afterwards.

    1. void SvSetMagicSV(SV* dsb, SV* ssv)
  • SvSetMagicSV_nosteal

    Like SvSetSV_nosteal , but does any set magic required afterwards.

    1. void SvSetMagicSV_nosteal(SV* dsv, SV* ssv)
  • SvSetSV

    Calls sv_setsv if dsv is not the same as ssv. May evaluate arguments more than once.

    1. void SvSetSV(SV* dsb, SV* ssv)
  • SvSetSV_nosteal

    Calls a non-destructive version of sv_setsv if dsv is not the same as ssv. May evaluate arguments more than once.

    1. void SvSetSV_nosteal(SV* dsv, SV* ssv)
  • SvSHARE

    Arranges for sv to be shared between threads if a suitable module has been loaded.

    1. void SvSHARE(SV* sv)
  • SvUNLOCK

    Releases a mutual exclusion lock on sv if a suitable module has been loaded.

    1. void SvUNLOCK(SV* sv)

Memory Management

  • Copy

    The XSUB-writer's interface to the C memcpy function. The src is the source, dest is the destination, nitems is the number of items, and type is the type. May fail on overlapping copies. See also Move .

    1. void Copy(void* src, void* dest, int nitems, type)
  • CopyD

    Like Copy but returns dest. Useful for encouraging compilers to tail-call optimise.

    1. void * CopyD(void* src, void* dest, int nitems, type)
  • Move

    The XSUB-writer's interface to the C memmove function. The src is the source, dest is the destination, nitems is the number of items, and type is the type. Can do overlapping moves. See also Copy .

    1. void Move(void* src, void* dest, int nitems, type)
  • MoveD

    Like Move but returns dest. Useful for encouraging compilers to tail-call optimise.

    1. void * MoveD(void* src, void* dest, int nitems, type)
  • Newx

    The XSUB-writer's interface to the C malloc function.

    In 5.9.3, Newx() and friends replace the older New() API, and drops the first parameter, x, a debug aid which allowed callers to identify themselves. This aid has been superseded by a new build option, PERL_MEM_LOG (see PERL_MEM_LOG in perlhack). The older API is still there for use in XS modules supporting older perls.

    1. void Newx(void* ptr, int nitems, type)
  • Newxc

    The XSUB-writer's interface to the C malloc function, with cast. See also Newx .

    1. void Newxc(void* ptr, int nitems, type, cast)
  • Newxz

    The XSUB-writer's interface to the C malloc function. The allocated memory is zeroed with memzero . See also Newx .

    1. void Newxz(void* ptr, int nitems, type)
  • Poison

    PoisonWith(0xEF) for catching access to freed memory.

    1. void Poison(void* dest, int nitems, type)
  • PoisonFree

    PoisonWith(0xEF) for catching access to freed memory.

    1. void PoisonFree(void* dest, int nitems, type)
  • PoisonNew

    PoisonWith(0xAB) for catching access to allocated but uninitialized memory.

    1. void PoisonNew(void* dest, int nitems, type)
  • PoisonWith

    Fill up memory with a byte pattern (a byte repeated over and over again) that hopefully catches attempts to access uninitialized memory.

    1. void PoisonWith(void* dest, int nitems, type, U8 byte)
  • Renew

    The XSUB-writer's interface to the C realloc function.

    1. void Renew(void* ptr, int nitems, type)
  • Renewc

    The XSUB-writer's interface to the C realloc function, with cast.

    1. void Renewc(void* ptr, int nitems, type, cast)
  • Safefree

    The XSUB-writer's interface to the C free function.

    1. void Safefree(void* ptr)
  • savepv

    Perl's version of strdup() . Returns a pointer to a newly allocated string which is a duplicate of pv . The size of the string is determined by strlen() . The memory allocated for the new string can be freed with the Safefree() function.

    1. char* savepv(const char* pv)
  • savepvn

    Perl's version of what strndup() would be if it existed. Returns a pointer to a newly allocated string which is a duplicate of the first len bytes from pv , plus a trailing NUL byte. The memory allocated for the new string can be freed with the Safefree() function.

    1. char* savepvn(const char* pv, I32 len)
  • savepvs

    Like savepvn , but takes a literal string instead of a string/length pair.

    1. char* savepvs(const char* s)
  • savesharedpv

    A version of savepv() which allocates the duplicate string in memory which is shared between threads.

    1. char* savesharedpv(const char* pv)
  • savesharedpvn

    A version of savepvn() which allocates the duplicate string in memory which is shared between threads. (With the specific difference that a NULL pointer is not acceptable)

    1. char* savesharedpvn(const char *const pv, const STRLEN len)
  • savesvpv

    A version of savepv() /savepvn() which gets the string to duplicate from the passed in SV using SvPV()

    1. char* savesvpv(SV* sv)
  • StructCopy

    This is an architecture-independent macro to copy one structure to another.

    1. void StructCopy(type src, type dest, type)
  • Zero

    The XSUB-writer's interface to the C memzero function. The dest is the destination, nitems is the number of items, and type is the type.

    1. void Zero(void* dest, int nitems, type)
  • ZeroD

    Like Zero but returns dest. Useful for encouraging compilers to tail-call optimise.

    1. void * ZeroD(void* dest, int nitems, type)

Miscellaneous Functions

  • fbm_compile

    Analyses the string in order to make fast searches on it using fbm_instr() -- the Boyer-Moore algorithm.

    1. void fbm_compile(SV* sv, U32 flags)
  • fbm_instr

    Returns the location of the SV in the string delimited by str and strend . It returns NULL if the string can't be found. The sv does not have to be fbm_compiled, but the search will not be as fast then.

    1. char* fbm_instr(unsigned char* big, unsigned char* bigend, SV* littlestr, U32 flags)
  • form

    Takes a sprintf-style format pattern and conventional (non-SV) arguments and returns the formatted string.

    1. (char *) Perl_form(pTHX_ const char* pat, ...)

    can be used any place a string (char *) is required:

    1. char * s = Perl_form("%d.%d",major,minor);

    Uses a single private buffer so if you want to format several strings you must explicitly copy the earlier strings away (and free the copies when you are done).

    1. char* form(const char* pat, ...)
  • getcwd_sv

    Fill the sv with current working directory

    1. int getcwd_sv(SV* sv)
  • my_snprintf

    The C library snprintf functionality, if available and standards-compliant (uses vsnprintf , actually). However, if the vsnprintf is not available, will unfortunately use the unsafe vsprintf which can overrun the buffer (there is an overrun check, but that may be too late). Consider using sv_vcatpvf instead, or getting vsnprintf .

    1. int my_snprintf(char *buffer, const Size_t len, const char *format, ...)
  • my_sprintf

    The C library sprintf, wrapped if necessary, to ensure that it will return the length of the string written to the buffer. Only rare pre-ANSI systems need the wrapper function - usually this is a direct call to sprintf.

    1. int my_sprintf(char *buffer, const char *pat, ...)
  • my_vsnprintf

    The C library vsnprintf if available and standards-compliant. However, if if the vsnprintf is not available, will unfortunately use the unsafe vsprintf which can overrun the buffer (there is an overrun check, but that may be too late). Consider using sv_vcatpvf instead, or getting vsnprintf .

    1. int my_vsnprintf(char *buffer, const Size_t len, const char *format, va_list ap)
  • new_version

    Returns a new version object based on the passed in SV:

    1. SV *sv = new_version(SV *ver);

    Does not alter the passed in ver SV. See "upg_version" if you want to upgrade the SV.

    1. SV* new_version(SV *ver)
  • prescan_version
    1. const char* prescan_version(const char *s, bool strict, const char** errstr, bool *sqv, int *ssaw_decimal, int *swidth, bool *salpha)
  • scan_version

    Returns a pointer to the next character after the parsed version string, as well as upgrading the passed in SV to an RV.

    Function must be called with an already existing SV like

    1. sv = newSV(0);
    2. s = scan_version(s, SV *sv, bool qv);

    Performs some preprocessing to the string to ensure that it has the correct characteristics of a version. Flags the object if it contains an underscore (which denotes this is an alpha version). The boolean qv denotes that the version should be interpreted as if it had multiple decimals, even if it doesn't.

    1. const char* scan_version(const char *s, SV *rv, bool qv)
  • strEQ

    Test two strings to see if they are equal. Returns true or false.

    1. bool strEQ(char* s1, char* s2)
  • strGE

    Test two strings to see if the first, s1 , is greater than or equal to the second, s2 . Returns true or false.

    1. bool strGE(char* s1, char* s2)
  • strGT

    Test two strings to see if the first, s1 , is greater than the second, s2 . Returns true or false.

    1. bool strGT(char* s1, char* s2)
  • strLE

    Test two strings to see if the first, s1 , is less than or equal to the second, s2 . Returns true or false.

    1. bool strLE(char* s1, char* s2)
  • strLT

    Test two strings to see if the first, s1 , is less than the second, s2 . Returns true or false.

    1. bool strLT(char* s1, char* s2)
  • strNE

    Test two strings to see if they are different. Returns true or false.

    1. bool strNE(char* s1, char* s2)
  • strnEQ

    Test two strings to see if they are equal. The len parameter indicates the number of bytes to compare. Returns true or false. (A wrapper for strncmp ).

    1. bool strnEQ(char* s1, char* s2, STRLEN len)
  • strnNE

    Test two strings to see if they are different. The len parameter indicates the number of bytes to compare. Returns true or false. (A wrapper for strncmp ).

    1. bool strnNE(char* s1, char* s2, STRLEN len)
  • sv_destroyable

    Dummy routine which reports that object can be destroyed when there is no sharing module present. It ignores its single SV argument, and returns 'true'. Exists to avoid test for a NULL function pointer and because it could potentially warn under some level of strict-ness.

    1. bool sv_destroyable(SV *sv)
  • sv_nosharing

    Dummy routine which "shares" an SV when there is no sharing module present. Or "locks" it. Or "unlocks" it. In other words, ignores its single SV argument. Exists to avoid test for a NULL function pointer and because it could potentially warn under some level of strict-ness.

    1. void sv_nosharing(SV *sv)
  • upg_version

    In-place upgrade of the supplied SV to a version object.

    1. SV *sv = upg_version(SV *sv, bool qv);

    Returns a pointer to the upgraded SV. Set the boolean qv if you want to force this SV to be interpreted as an "extended" version.

    1. SV* upg_version(SV *ver, bool qv)
  • vcmp

    Version object aware cmp. Both operands must already have been converted into version objects.

    1. int vcmp(SV *lhv, SV *rhv)
  • vnormal

    Accepts a version object and returns the normalized string representation. Call like:

    1. sv = vnormal(rv);

    NOTE: you can pass either the object directly or the SV contained within the RV.

    1. SV* vnormal(SV *vs)
  • vnumify

    Accepts a version object and returns the normalized floating point representation. Call like:

    1. sv = vnumify(rv);

    NOTE: you can pass either the object directly or the SV contained within the RV.

    1. SV* vnumify(SV *vs)
  • vstringify

    In order to maintain maximum compatibility with earlier versions of Perl, this function will return either the floating point notation or the multiple dotted notation, depending on whether the original version contained 1 or more dots, respectively

    1. SV* vstringify(SV *vs)
  • vverify

    Validates that the SV contains a valid version object.

    1. bool vverify(SV *vobj);

    Note that it only confirms the bare minimum structure (so as not to get confused by derived classes which may contain additional hash entries):

    1. bool vverify(SV *vs)

MRO Functions

  • mro_get_linear_isa

    Returns either mro_get_linear_isa_c3 or mro_get_linear_isa_dfs for the given stash, dependant upon which MRO is in effect for that stash. The return value is a read-only AV*.

    You are responsible for SvREFCNT_inc() on the return value if you plan to store it anywhere semi-permanently (otherwise it might be deleted out from under you the next time the cache is invalidated).

    1. AV* mro_get_linear_isa(HV* stash)
  • mro_method_changed_in

    Invalidates method caching on any child classes of the given stash, so that they might notice the changes in this one.

    Ideally, all instances of PL_sub_generation++ in perl source outside of mro.c should be replaced by calls to this.

    Perl automatically handles most of the common ways a method might be redefined. However, there are a few ways you could change a method in a stash without the cache code noticing, in which case you need to call this method afterwards:

    1) Directly manipulating the stash HV entries from XS code.

    2) Assigning a reference to a readonly scalar constant into a stash entry in order to create a constant subroutine (like constant.pm does).

    This same method is available from pure perl via, mro::method_changed_in(classname) .

    1. void mro_method_changed_in(HV* stash)

Multicall Functions

Numeric functions

  • grok_bin

    converts a string representing a binary number to numeric form.

    On entry start and *len give the string to scan, *flags gives conversion flags, and result should be NULL or a pointer to an NV. The scan stops at the end of the string, or the first invalid character. Unless PERL_SCAN_SILENT_ILLDIGIT is set in *flags, encountering an invalid character will also trigger a warning. On return *len is set to the length of the scanned string, and *flags gives output flags.

    If the value is <= UV_MAX it is returned as a UV, the output flags are clear, and nothing is written to *result. If the value is > UV_MAX grok_bin returns UV_MAX, sets PERL_SCAN_GREATER_THAN_UV_MAX in the output flags, and writes the value to *result (or the value is discarded if result is NULL).

    The binary number may optionally be prefixed with "0b" or "b" unless PERL_SCAN_DISALLOW_PREFIX is set in *flags on entry. If PERL_SCAN_ALLOW_UNDERSCORES is set in *flags then the binary number may use '_' characters to separate digits.

    1. UV grok_bin(const char* start, STRLEN* len_p, I32* flags, NV *result)
  • grok_hex

    converts a string representing a hex number to numeric form.

    On entry start and *len give the string to scan, *flags gives conversion flags, and result should be NULL or a pointer to an NV. The scan stops at the end of the string, or the first invalid character. Unless PERL_SCAN_SILENT_ILLDIGIT is set in *flags, encountering an invalid character will also trigger a warning. On return *len is set to the length of the scanned string, and *flags gives output flags.

    If the value is <= UV_MAX it is returned as a UV, the output flags are clear, and nothing is written to *result. If the value is > UV_MAX grok_hex returns UV_MAX, sets PERL_SCAN_GREATER_THAN_UV_MAX in the output flags, and writes the value to *result (or the value is discarded if result is NULL).

    The hex number may optionally be prefixed with "0x" or "x" unless PERL_SCAN_DISALLOW_PREFIX is set in *flags on entry. If PERL_SCAN_ALLOW_UNDERSCORES is set in *flags then the hex number may use '_' characters to separate digits.

    1. UV grok_hex(const char* start, STRLEN* len_p, I32* flags, NV *result)
  • grok_number

    Recognise (or not) a number. The type of the number is returned (0 if unrecognised), otherwise it is a bit-ORed combination of IS_NUMBER_IN_UV, IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT, IS_NUMBER_NEG, IS_NUMBER_INFINITY, IS_NUMBER_NAN (defined in perl.h).

    If the value of the number can fit an in UV, it is returned in the *valuep IS_NUMBER_IN_UV will be set to indicate that *valuep is valid, IS_NUMBER_IN_UV will never be set unless *valuep is valid, but *valuep may have been assigned to during processing even though IS_NUMBER_IN_UV is not set on return. If valuep is NULL, IS_NUMBER_IN_UV will be set for the same cases as when valuep is non-NULL, but no actual assignment (or SEGV) will occur.

    IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV if trailing decimals were seen (in which case *valuep gives the true value truncated to an integer), and IS_NUMBER_NEG if the number is negative (in which case *valuep holds the absolute value). IS_NUMBER_IN_UV is not set if e notation was used or the number is larger than a UV.

    1. int grok_number(const char *pv, STRLEN len, UV *valuep)
  • grok_numeric_radix

    Scan and skip for a numeric decimal separator (radix).

    1. bool grok_numeric_radix(const char **sp, const char *send)
  • grok_oct

    converts a string representing an octal number to numeric form.

    On entry start and *len give the string to scan, *flags gives conversion flags, and result should be NULL or a pointer to an NV. The scan stops at the end of the string, or the first invalid character. Unless PERL_SCAN_SILENT_ILLDIGIT is set in *flags, encountering an invalid character will also trigger a warning. On return *len is set to the length of the scanned string, and *flags gives output flags.

    If the value is <= UV_MAX it is returned as a UV, the output flags are clear, and nothing is written to *result. If the value is > UV_MAX grok_oct returns UV_MAX, sets PERL_SCAN_GREATER_THAN_UV_MAX in the output flags, and writes the value to *result (or the value is discarded if result is NULL).

    If PERL_SCAN_ALLOW_UNDERSCORES is set in *flags then the octal number may use '_' characters to separate digits.

    1. UV grok_oct(const char* start, STRLEN* len_p, I32* flags, NV *result)
  • Perl_signbit

    Return a non-zero integer if the sign bit on an NV is set, and 0 if it is not.

    If Configure detects this system has a signbit() that will work with our NVs, then we just use it via the #define in perl.h. Otherwise, fall back on this implementation. As a first pass, this gets everything right except -0.0. Alas, catching -0.0 is the main use for this function, so this is not too helpful yet. Still, at least we have the scaffolding in place to support other systems, should that prove useful.

    Configure notes: This function is called 'Perl_signbit' instead of a plain 'signbit' because it is easy to imagine a system having a signbit() function or macro that doesn't happen to work with our particular choice of NVs. We shouldn't just re-#define signbit as Perl_signbit and expect the standard system headers to be happy. Also, this is a no-context function (no pTHX_) because Perl_signbit() is usually re-#defined in perl.h as a simple macro call to the system's signbit(). Users should just always call Perl_signbit().

    NOTE: this function is experimental and may change or be removed without notice.

    1. int Perl_signbit(NV f)
  • scan_bin

    For backwards compatibility. Use grok_bin instead.

    1. NV scan_bin(const char* start, STRLEN len, STRLEN* retlen)
  • scan_hex

    For backwards compatibility. Use grok_hex instead.

    1. NV scan_hex(const char* start, STRLEN len, STRLEN* retlen)
  • scan_oct

    For backwards compatibility. Use grok_oct instead.

    1. NV scan_oct(const char* start, STRLEN len, STRLEN* retlen)

Optree Manipulation Functions

  • cv_const_sv

    If cv is a constant sub eligible for inlining. returns the constant value returned by the sub. Otherwise, returns NULL.

    Constant subs can be created with newCONSTSUB or as described in Constant Functions in perlsub.

    1. SV* cv_const_sv(const CV *const cv)
  • newCONSTSUB

    Creates a constant sub equivalent to Perl sub FOO () { 123 } which is eligible for inlining at compile-time.

    Passing NULL for SV creates a constant sub equivalent to sub BAR () {} , which won't be called if used as a destructor, but will suppress the overhead of a call to AUTOLOAD . (This form, however, isn't eligible for inlining at compile time.)

    1. CV* newCONSTSUB(HV* stash, const char* name, SV* sv)
  • newXS

    Used by xsubpp to hook up XSUBs as Perl subs. filename needs to be static storage, as it is used directly as CvFILE(), without a copy being made.

Pad Data Structures

  • pad_findmy

    Given a lexical name, try to find its offset, first in the current pad, or failing that, in the pads of any lexically enclosing subs (including the complications introduced by eval). If the name is found in an outer pad, then a fake entry is added to the current pad. Returns the offset in the current pad, or NOT_IN_PAD on failure.

    NOTE: this function is experimental and may change or be removed without notice.

    1. PADOFFSET pad_findmy(const char* name, STRLEN len, U32 flags)
  • pad_sv

    Get the value at offset po in the current pad. Use macro PAD_SV instead of calling this function directly.

    1. SV* pad_sv(PADOFFSET po)

Per-Interpreter Variables

  • PL_modglobal

    PL_modglobal is a general purpose, interpreter global HV for use by extensions that need to keep information on a per-interpreter basis. In a pinch, it can also be used as a symbol table for extensions to share data among each other. It is a good idea to use keys prefixed by the package name of the extension that owns the data.

    1. HV* PL_modglobal
  • PL_na

    A convenience variable which is typically used with SvPV when one doesn't care about the length of the string. It is usually more efficient to either declare a local variable and use that instead or to use the SvPV_nolen macro.

    1. STRLEN PL_na
  • PL_opfreehook

    When non-NULL , the function pointed by this variable will be called each time an OP is freed with the corresponding OP as the argument. This allows extensions to free any extra attribute they have locally attached to an OP. It is also assured to first fire for the parent OP and then for its kids.

    When you replace this variable, it is considered a good practice to store the possibly previously installed hook and that you recall it inside your own.

    1. Perl_ophook_t PL_opfreehook
  • PL_sv_no

    This is the false SV. See PL_sv_yes . Always refer to this as &PL_sv_no .

    1. SV PL_sv_no
  • PL_sv_undef

    This is the undef SV. Always refer to this as &PL_sv_undef .

    1. SV PL_sv_undef
  • PL_sv_yes

    This is the true SV. See PL_sv_no . Always refer to this as &PL_sv_yes .

    1. SV PL_sv_yes

REGEXP Functions

  • SvRX

    Convenience macro to get the REGEXP from a SV. This is approximately equivalent to the following snippet:

    1. if (SvMAGICAL(sv))
    2. mg_get(sv);
    3. if (SvROK(sv) &&
    4. (tmpsv = (SV*)SvRV(sv)) &&
    5. SvTYPE(tmpsv) == SVt_PVMG &&
    6. (tmpmg = mg_find(tmpsv, PERL_MAGIC_qr)))
    7. {
    8. return (REGEXP *)tmpmg->mg_obj;
    9. }

    NULL will be returned if a REGEXP* is not found.

    1. REGEXP * SvRX(SV *sv)
  • SvRXOK

    Returns a boolean indicating whether the SV contains qr magic (PERL_MAGIC_qr).

    If you want to do something with the REGEXP* later use SvRX instead and check for NULL.

    1. bool SvRXOK(SV* sv)

Simple Exception Handling Macros

Stack Manipulation Macros

  • dMARK

    Declare a stack marker variable, mark , for the XSUB. See MARK and dORIGMARK .

    1. dMARK;
  • dORIGMARK

    Saves the original stack mark for the XSUB. See ORIGMARK .

    1. dORIGMARK;
  • dSP

    Declares a local copy of perl's stack pointer for the XSUB, available via the SP macro. See SP .

    1. dSP;
  • EXTEND

    Used to extend the argument stack for an XSUB's return values. Once used, guarantees that there is room for at least nitems to be pushed onto the stack.

    1. void EXTEND(SP, int nitems)
  • MARK

    Stack marker variable for the XSUB. See dMARK .

  • mPUSHi

    Push an integer onto the stack. The stack must have room for this element. Does not use TARG . See also PUSHi , mXPUSHi and XPUSHi .

    1. void mPUSHi(IV iv)
  • mPUSHn

    Push a double onto the stack. The stack must have room for this element. Does not use TARG . See also PUSHn , mXPUSHn and XPUSHn .

    1. void mPUSHn(NV nv)
  • mPUSHp

    Push a string onto the stack. The stack must have room for this element. The len indicates the length of the string. Does not use TARG . See also PUSHp , mXPUSHp and XPUSHp .

    1. void mPUSHp(char* str, STRLEN len)
  • mPUSHs

    Push an SV onto the stack and mortalizes the SV. The stack must have room for this element. Does not use TARG . See also PUSHs and mXPUSHs .

    1. void mPUSHs(SV* sv)
  • mPUSHu

    Push an unsigned integer onto the stack. The stack must have room for this element. Does not use TARG . See also PUSHu , mXPUSHu and XPUSHu .

    1. void mPUSHu(UV uv)
  • mXPUSHi

    Push an integer onto the stack, extending the stack if necessary. Does not use TARG . See also XPUSHi , mPUSHi and PUSHi .

    1. void mXPUSHi(IV iv)
  • mXPUSHn

    Push a double onto the stack, extending the stack if necessary. Does not use TARG . See also XPUSHn , mPUSHn and PUSHn .

    1. void mXPUSHn(NV nv)
  • mXPUSHp

    Push a string onto the stack, extending the stack if necessary. The len indicates the length of the string. Does not use TARG . See also XPUSHp , mPUSHp and PUSHp .

    1. void mXPUSHp(char* str, STRLEN len)
  • mXPUSHs

    Push an SV onto the stack, extending the stack if necessary and mortalizes the SV. Does not use TARG . See also XPUSHs and mPUSHs .

    1. void mXPUSHs(SV* sv)
  • mXPUSHu

    Push an unsigned integer onto the stack, extending the stack if necessary. Does not use TARG . See also XPUSHu , mPUSHu and PUSHu .

    1. void mXPUSHu(UV uv)
  • ORIGMARK

    The original stack mark for the XSUB. See dORIGMARK .

  • POPi

    Pops an integer off the stack.

    1. IV POPi
  • POPl

    Pops a long off the stack.

    1. long POPl
  • POPn

    Pops a double off the stack.

    1. NV POPn
  • POPp

    Pops a string off the stack. Deprecated. New code should use POPpx.

    1. char* POPp
  • POPpbytex

    Pops a string off the stack which must consist of bytes i.e. characters < 256.

    1. char* POPpbytex
  • POPpx

    Pops a string off the stack.

    1. char* POPpx
  • POPs

    Pops an SV off the stack.

    1. SV* POPs
  • PUSHi

    Push an integer onto the stack. The stack must have room for this element. Handles 'set' magic. Uses TARG , so dTARGET or dXSTARG should be called to declare it. Do not call multiple TARG -oriented macros to return lists from XSUB's - see mPUSHi instead. See also XPUSHi and mXPUSHi .

    1. void PUSHi(IV iv)
  • PUSHMARK

    Opening bracket for arguments on a callback. See PUTBACK and perlcall.

    1. void PUSHMARK(SP)
  • PUSHmortal

    Push a new mortal SV onto the stack. The stack must have room for this element. Does not use TARG . See also PUSHs , XPUSHmortal and XPUSHs .

    1. void PUSHmortal()
  • PUSHn

    Push a double onto the stack. The stack must have room for this element. Handles 'set' magic. Uses TARG , so dTARGET or dXSTARG should be called to declare it. Do not call multiple TARG -oriented macros to return lists from XSUB's - see mPUSHn instead. See also XPUSHn and mXPUSHn .

    1. void PUSHn(NV nv)
  • PUSHp

    Push a string onto the stack. The stack must have room for this element. The len indicates the length of the string. Handles 'set' magic. Uses TARG , so dTARGET or dXSTARG should be called to declare it. Do not call multiple TARG -oriented macros to return lists from XSUB's - see mPUSHp instead. See also XPUSHp and mXPUSHp .

    1. void PUSHp(char* str, STRLEN len)
  • PUSHs

    Push an SV onto the stack. The stack must have room for this element. Does not handle 'set' magic. Does not use TARG . See also PUSHmortal , XPUSHs and XPUSHmortal .

    1. void PUSHs(SV* sv)
  • PUSHu

    Push an unsigned integer onto the stack. The stack must have room for this element. Handles 'set' magic. Uses TARG , so dTARGET or dXSTARG should be called to declare it. Do not call multiple TARG -oriented macros to return lists from XSUB's - see mPUSHu instead. See also XPUSHu and mXPUSHu .

    1. void PUSHu(UV uv)
  • PUTBACK

    Closing bracket for XSUB arguments. This is usually handled by xsubpp . See PUSHMARK and perlcall for other uses.

    1. PUTBACK;
  • SP

    Stack pointer. This is usually handled by xsubpp . See dSP and SPAGAIN .

  • SPAGAIN

    Refetch the stack pointer. Used after a callback. See perlcall.

    1. SPAGAIN;
  • XPUSHi

    Push an integer onto the stack, extending the stack if necessary. Handles 'set' magic. Uses TARG , so dTARGET or dXSTARG should be called to declare it. Do not call multiple TARG -oriented macros to return lists from XSUB's - see mXPUSHi instead. See also PUSHi and mPUSHi .

    1. void XPUSHi(IV iv)
  • XPUSHmortal

    Push a new mortal SV onto the stack, extending the stack if necessary. Does not use TARG . See also XPUSHs , PUSHmortal and PUSHs .

    1. void XPUSHmortal()
  • XPUSHn

    Push a double onto the stack, extending the stack if necessary. Handles 'set' magic. Uses TARG , so dTARGET or dXSTARG should be called to declare it. Do not call multiple TARG -oriented macros to return lists from XSUB's - see mXPUSHn instead. See also PUSHn and mPUSHn .

    1. void XPUSHn(NV nv)
  • XPUSHp

    Push a string onto the stack, extending the stack if necessary. The len indicates the length of the string. Handles 'set' magic. Uses TARG , so dTARGET or dXSTARG should be called to declare it. Do not call multiple TARG -oriented macros to return lists from XSUB's - see mXPUSHp instead. See also PUSHp and mPUSHp .

    1. void XPUSHp(char* str, STRLEN len)
  • XPUSHs

    Push an SV onto the stack, extending the stack if necessary. Does not handle 'set' magic. Does not use TARG . See also XPUSHmortal , PUSHs and PUSHmortal .

    1. void XPUSHs(SV* sv)
  • XPUSHu

    Push an unsigned integer onto the stack, extending the stack if necessary. Handles 'set' magic. Uses TARG , so dTARGET or dXSTARG should be called to declare it. Do not call multiple TARG -oriented macros to return lists from XSUB's - see mXPUSHu instead. See also PUSHu and mPUSHu .

    1. void XPUSHu(UV uv)
  • XSRETURN

    Return from XSUB, indicating number of items on the stack. This is usually handled by xsubpp .

    1. void XSRETURN(int nitems)
  • XSRETURN_EMPTY

    Return an empty list from an XSUB immediately.

    1. XSRETURN_EMPTY;
  • XSRETURN_IV

    Return an integer from an XSUB immediately. Uses XST_mIV .

    1. void XSRETURN_IV(IV iv)
  • XSRETURN_NO

    Return &PL_sv_no from an XSUB immediately. Uses XST_mNO .

    1. XSRETURN_NO;
  • XSRETURN_NV

    Return a double from an XSUB immediately. Uses XST_mNV .

    1. void XSRETURN_NV(NV nv)
  • XSRETURN_PV

    Return a copy of a string from an XSUB immediately. Uses XST_mPV .

    1. void XSRETURN_PV(char* str)
  • XSRETURN_UNDEF

    Return &PL_sv_undef from an XSUB immediately. Uses XST_mUNDEF .

    1. XSRETURN_UNDEF;
  • XSRETURN_UV

    Return an integer from an XSUB immediately. Uses XST_mUV .

    1. void XSRETURN_UV(IV uv)
  • XSRETURN_YES

    Return &PL_sv_yes from an XSUB immediately. Uses XST_mYES .

    1. XSRETURN_YES;
  • XST_mIV

    Place an integer into the specified position pos on the stack. The value is stored in a new mortal SV.

    1. void XST_mIV(int pos, IV iv)
  • XST_mNO

    Place &PL_sv_no into the specified position pos on the stack.

    1. void XST_mNO(int pos)
  • XST_mNV

    Place a double into the specified position pos on the stack. The value is stored in a new mortal SV.

    1. void XST_mNV(int pos, NV nv)
  • XST_mPV

    Place a copy of a string into the specified position pos on the stack. The value is stored in a new mortal SV.

    1. void XST_mPV(int pos, char* str)
  • XST_mUNDEF

    Place &PL_sv_undef into the specified position pos on the stack.

    1. void XST_mUNDEF(int pos)
  • XST_mYES

    Place &PL_sv_yes into the specified position pos on the stack.

    1. void XST_mYES(int pos)

SV Flags

  • svtype

    An enum of flags for Perl types. These are found in the file sv.h in the svtype enum. Test these flags with the SvTYPE macro.

  • SVt_IV

    Integer type flag for scalars. See svtype .

  • SVt_NV

    Double type flag for scalars. See svtype .

  • SVt_PV

    Pointer type flag for scalars. See svtype .

  • SVt_PVAV

    Type flag for arrays. See svtype .

  • SVt_PVCV

    Type flag for code refs. See svtype .

  • SVt_PVHV

    Type flag for hashes. See svtype .

  • SVt_PVMG

    Type flag for blessed scalars. See svtype .

SV Manipulation Functions

  • croak_xs_usage

    A specialised variant of croak() for emitting the usage message for xsubs

    1. croak_xs_usage(cv, "eee_yow");

    works out the package name and subroutine name from cv , and then calls croak() . Hence if cv is &ouch::awk , it would call croak as:

    1. Perl_croak(aTHX_ "Usage %s::%s(%s)", "ouch" "awk", "eee_yow");
    2. void croak_xs_usage(const CV *const cv, const char *const params)
  • get_sv

    Returns the SV of the specified Perl scalar. flags are passed to gv_fetchpv . If GV_ADD is set and the Perl variable does not exist then it will be created. If flags is zero and the variable does not exist then NULL is returned.

    NOTE: the perl_ form of this function is deprecated.

    1. SV* get_sv(const char *name, I32 flags)
  • newRV_inc

    Creates an RV wrapper for an SV. The reference count for the original SV is incremented.

    1. SV* newRV_inc(SV* sv)
  • newSVpvn_utf8

    Creates a new SV and copies a string into it. If utf8 is true, calls SvUTF8_on on the new SV. Implemented as a wrapper around newSVpvn_flags .

    1. SV* newSVpvn_utf8(NULLOK const char* s, STRLEN len, U32 utf8)
  • SvCUR

    Returns the length of the string which is in the SV. See SvLEN .

    1. STRLEN SvCUR(SV* sv)
  • SvCUR_set

    Set the current length of the string which is in the SV. See SvCUR and SvIV_set .

    1. void SvCUR_set(SV* sv, STRLEN len)
  • SvEND

    Returns a pointer to the last character in the string which is in the SV. See SvCUR . Access the character as *(SvEND(sv)).

    1. char* SvEND(SV* sv)
  • SvGAMAGIC

    Returns true if the SV has get magic or overloading. If either is true then the scalar is active data, and has the potential to return a new value every time it is accessed. Hence you must be careful to only read it once per user logical operation and work with that returned value. If neither is true then the scalar's value cannot change unless written to.

    1. U32 SvGAMAGIC(SV* sv)
  • SvGROW

    Expands the character buffer in the SV so that it has room for the indicated number of bytes (remember to reserve space for an extra trailing NUL character). Calls sv_grow to perform the expansion if necessary. Returns a pointer to the character buffer.

    1. char * SvGROW(SV* sv, STRLEN len)
  • SvIOK

    Returns a U32 value indicating whether the SV contains an integer.

    1. U32 SvIOK(SV* sv)
  • SvIOKp

    Returns a U32 value indicating whether the SV contains an integer. Checks the private setting. Use SvIOK instead.

    1. U32 SvIOKp(SV* sv)
  • SvIOK_notUV

    Returns a boolean indicating whether the SV contains a signed integer.

    1. bool SvIOK_notUV(SV* sv)
  • SvIOK_off

    Unsets the IV status of an SV.

    1. void SvIOK_off(SV* sv)
  • SvIOK_on

    Tells an SV that it is an integer.

    1. void SvIOK_on(SV* sv)
  • SvIOK_only

    Tells an SV that it is an integer and disables all other OK bits.

    1. void SvIOK_only(SV* sv)
  • SvIOK_only_UV

    Tells and SV that it is an unsigned integer and disables all other OK bits.

    1. void SvIOK_only_UV(SV* sv)
  • SvIOK_UV

    Returns a boolean indicating whether the SV contains an unsigned integer.

    1. bool SvIOK_UV(SV* sv)
  • SvIsCOW

    Returns a boolean indicating whether the SV is Copy-On-Write. (either shared hash key scalars, or full Copy On Write scalars if 5.9.0 is configured for COW)

    1. bool SvIsCOW(SV* sv)
  • SvIsCOW_shared_hash

    Returns a boolean indicating whether the SV is Copy-On-Write shared hash key scalar.

    1. bool SvIsCOW_shared_hash(SV* sv)
  • SvIV

    Coerces the given SV to an integer and returns it. See SvIVx for a version which guarantees to evaluate sv only once.

    1. IV SvIV(SV* sv)
  • SvIVX

    Returns the raw value in the SV's IV slot, without checks or conversions. Only use when you are sure SvIOK is true. See also SvIV() .

    1. IV SvIVX(SV* sv)
  • SvIVx

    Coerces the given SV to an integer and returns it. Guarantees to evaluate sv only once. Only use this if sv is an expression with side effects, otherwise use the more efficient SvIV .

    1. IV SvIVx(SV* sv)
  • SvIV_nomg

    Like SvIV but doesn't process magic.

    1. IV SvIV_nomg(SV* sv)
  • SvIV_set

    Set the value of the IV pointer in sv to val. It is possible to perform the same function of this macro with an lvalue assignment to SvIVX . With future Perls, however, it will be more efficient to use SvIV_set instead of the lvalue assignment to SvIVX .

    1. void SvIV_set(SV* sv, IV val)
  • SvLEN

    Returns the size of the string buffer in the SV, not including any part attributable to SvOOK . See SvCUR .

    1. STRLEN SvLEN(SV* sv)
  • SvLEN_set

    Set the actual length of the string which is in the SV. See SvIV_set .

    1. void SvLEN_set(SV* sv, STRLEN len)
  • SvMAGIC_set

    Set the value of the MAGIC pointer in sv to val. See SvIV_set .

    1. void SvMAGIC_set(SV* sv, MAGIC* val)
  • SvNIOK

    Returns a U32 value indicating whether the SV contains a number, integer or double.

    1. U32 SvNIOK(SV* sv)
  • SvNIOKp

    Returns a U32 value indicating whether the SV contains a number, integer or double. Checks the private setting. Use SvNIOK instead.

    1. U32 SvNIOKp(SV* sv)
  • SvNIOK_off

    Unsets the NV/IV status of an SV.

    1. void SvNIOK_off(SV* sv)
  • SvNOK

    Returns a U32 value indicating whether the SV contains a double.

    1. U32 SvNOK(SV* sv)
  • SvNOKp

    Returns a U32 value indicating whether the SV contains a double. Checks the private setting. Use SvNOK instead.

    1. U32 SvNOKp(SV* sv)
  • SvNOK_off

    Unsets the NV status of an SV.

    1. void SvNOK_off(SV* sv)
  • SvNOK_on

    Tells an SV that it is a double.

    1. void SvNOK_on(SV* sv)
  • SvNOK_only

    Tells an SV that it is a double and disables all other OK bits.

    1. void SvNOK_only(SV* sv)
  • SvNV

    Coerce the given SV to a double and return it. See SvNVx for a version which guarantees to evaluate sv only once.

    1. NV SvNV(SV* sv)
  • SvNVX

    Returns the raw value in the SV's NV slot, without checks or conversions. Only use when you are sure SvNOK is true. See also SvNV() .

    1. NV SvNVX(SV* sv)
  • SvNVx

    Coerces the given SV to a double and returns it. Guarantees to evaluate sv only once. Only use this if sv is an expression with side effects, otherwise use the more efficient SvNV .

    1. NV SvNVx(SV* sv)
  • SvNV_set

    Set the value of the NV pointer in sv to val. See SvIV_set .

    1. void SvNV_set(SV* sv, NV val)
  • SvOK

    Returns a U32 value indicating whether the value is defined. This is only meaningful for scalars.

    1. U32 SvOK(SV* sv)
  • SvOOK

    Returns a U32 indicating whether the pointer to the string buffer is offset. This hack is used internally to speed up removal of characters from the beginning of a SvPV. When SvOOK is true, then the start of the allocated string buffer is actually SvOOK_offset() bytes before SvPVX. This offset used to be stored in SvIVX, but is now stored within the spare part of the buffer.

    1. U32 SvOOK(SV* sv)
  • SvOOK_offset

    Reads into len the offset from SvPVX back to the true start of the allocated buffer, which will be non-zero if sv_chop has been used to efficiently remove characters from start of the buffer. Implemented as a macro, which takes the address of len, which must be of type STRLEN . Evaluates sv more than once. Sets len to 0 if SvOOK(sv) is false.

    1. void SvOOK_offset(NN SV*sv, STRLEN len)
  • SvPOK

    Returns a U32 value indicating whether the SV contains a character string.

    1. U32 SvPOK(SV* sv)
  • SvPOKp

    Returns a U32 value indicating whether the SV contains a character string. Checks the private setting. Use SvPOK instead.

    1. U32 SvPOKp(SV* sv)
  • SvPOK_off

    Unsets the PV status of an SV.

    1. void SvPOK_off(SV* sv)
  • SvPOK_on

    Tells an SV that it is a string.

    1. void SvPOK_on(SV* sv)
  • SvPOK_only

    Tells an SV that it is a string and disables all other OK bits. Will also turn off the UTF-8 status.

    1. void SvPOK_only(SV* sv)
  • SvPOK_only_UTF8

    Tells an SV that it is a string and disables all other OK bits, and leaves the UTF-8 status as it was.

    1. void SvPOK_only_UTF8(SV* sv)
  • SvPV

    Returns a pointer to the string in the SV, or a stringified form of the SV if the SV does not contain a string. The SV may cache the stringified version becoming SvPOK . Handles 'get' magic. See also SvPVx for a version which guarantees to evaluate sv only once.

    1. char* SvPV(SV* sv, STRLEN len)
  • SvPVbyte

    Like SvPV , but converts sv to byte representation first if necessary.

    1. char* SvPVbyte(SV* sv, STRLEN len)
  • SvPVbytex

    Like SvPV , but converts sv to byte representation first if necessary. Guarantees to evaluate sv only once; use the more efficient SvPVbyte otherwise.

    1. char* SvPVbytex(SV* sv, STRLEN len)
  • SvPVbytex_force

    Like SvPV_force , but converts sv to byte representation first if necessary. Guarantees to evaluate sv only once; use the more efficient SvPVbyte_force otherwise.

    1. char* SvPVbytex_force(SV* sv, STRLEN len)
  • SvPVbyte_force

    Like SvPV_force , but converts sv to byte representation first if necessary.

    1. char* SvPVbyte_force(SV* sv, STRLEN len)
  • SvPVbyte_nolen

    Like SvPV_nolen , but converts sv to byte representation first if necessary.

    1. char* SvPVbyte_nolen(SV* sv)
  • SvPVutf8

    Like SvPV , but converts sv to utf8 first if necessary.

    1. char* SvPVutf8(SV* sv, STRLEN len)
  • SvPVutf8x

    Like SvPV , but converts sv to utf8 first if necessary. Guarantees to evaluate sv only once; use the more efficient SvPVutf8 otherwise.

    1. char* SvPVutf8x(SV* sv, STRLEN len)
  • SvPVutf8x_force

    Like SvPV_force , but converts sv to utf8 first if necessary. Guarantees to evaluate sv only once; use the more efficient SvPVutf8_force otherwise.

    1. char* SvPVutf8x_force(SV* sv, STRLEN len)
  • SvPVutf8_force

    Like SvPV_force , but converts sv to utf8 first if necessary.

    1. char* SvPVutf8_force(SV* sv, STRLEN len)
  • SvPVutf8_nolen

    Like SvPV_nolen , but converts sv to utf8 first if necessary.

    1. char* SvPVutf8_nolen(SV* sv)
  • SvPVX

    Returns a pointer to the physical string in the SV. The SV must contain a string.

    1. char* SvPVX(SV* sv)
  • SvPVx

    A version of SvPV which guarantees to evaluate sv only once. Only use this if sv is an expression with side effects, otherwise use the more efficient SvPVX .

    1. char* SvPVx(SV* sv, STRLEN len)
  • SvPV_force

    Like SvPV but will force the SV into containing just a string (SvPOK_only ). You want force if you are going to update the SvPVX directly.

    1. char* SvPV_force(SV* sv, STRLEN len)
  • SvPV_force_nomg

    Like SvPV but will force the SV into containing just a string (SvPOK_only ). You want force if you are going to update the SvPVX directly. Doesn't process magic.

    1. char* SvPV_force_nomg(SV* sv, STRLEN len)
  • SvPV_nolen

    Returns a pointer to the string in the SV, or a stringified form of the SV if the SV does not contain a string. The SV may cache the stringified form becoming SvPOK . Handles 'get' magic.

    1. char* SvPV_nolen(SV* sv)
  • SvPV_nomg

    Like SvPV but doesn't process magic.

    1. char* SvPV_nomg(SV* sv, STRLEN len)
  • SvPV_set

    Set the value of the PV pointer in sv to val. See SvIV_set .

    1. void SvPV_set(SV* sv, char* val)
  • SvREFCNT

    Returns the value of the object's reference count.

    1. U32 SvREFCNT(SV* sv)
  • SvREFCNT_dec

    Decrements the reference count of the given SV.

    1. void SvREFCNT_dec(SV* sv)
  • SvREFCNT_inc

    Increments the reference count of the given SV.

    All of the following SvREFCNT_inc* macros are optimized versions of SvREFCNT_inc, and can be replaced with SvREFCNT_inc.

    1. SV* SvREFCNT_inc(SV* sv)
  • SvREFCNT_inc_NN

    Same as SvREFCNT_inc, but can only be used if you know sv is not NULL. Since we don't have to check the NULLness, it's faster and smaller.

    1. SV* SvREFCNT_inc_NN(SV* sv)
  • SvREFCNT_inc_simple

    Same as SvREFCNT_inc, but can only be used with expressions without side effects. Since we don't have to store a temporary value, it's faster.

    1. SV* SvREFCNT_inc_simple(SV* sv)
  • SvREFCNT_inc_simple_NN

    Same as SvREFCNT_inc_simple, but can only be used if you know sv is not NULL. Since we don't have to check the NULLness, it's faster and smaller.

    1. SV* SvREFCNT_inc_simple_NN(SV* sv)
  • SvREFCNT_inc_simple_void

    Same as SvREFCNT_inc_simple, but can only be used if you don't need the return value. The macro doesn't need to return a meaningful value.

    1. void SvREFCNT_inc_simple_void(SV* sv)
  • SvREFCNT_inc_simple_void_NN

    Same as SvREFCNT_inc, but can only be used if you don't need the return value, and you know that sv is not NULL. The macro doesn't need to return a meaningful value, or check for NULLness, so it's smaller and faster.

    1. void SvREFCNT_inc_simple_void_NN(SV* sv)
  • SvREFCNT_inc_void

    Same as SvREFCNT_inc, but can only be used if you don't need the return value. The macro doesn't need to return a meaningful value.

    1. void SvREFCNT_inc_void(SV* sv)
  • SvREFCNT_inc_void_NN

    Same as SvREFCNT_inc, but can only be used if you don't need the return value, and you know that sv is not NULL. The macro doesn't need to return a meaningful value, or check for NULLness, so it's smaller and faster.

    1. void SvREFCNT_inc_void_NN(SV* sv)
  • SvROK

    Tests if the SV is an RV.

    1. U32 SvROK(SV* sv)
  • SvROK_off

    Unsets the RV status of an SV.

    1. void SvROK_off(SV* sv)
  • SvROK_on

    Tells an SV that it is an RV.

    1. void SvROK_on(SV* sv)
  • SvRV

    Dereferences an RV to return the SV.

    1. SV* SvRV(SV* sv)
  • SvRV_set

    Set the value of the RV pointer in sv to val. See SvIV_set .

    1. void SvRV_set(SV* sv, SV* val)
  • SvSTASH

    Returns the stash of the SV.

    1. HV* SvSTASH(SV* sv)
  • SvSTASH_set

    Set the value of the STASH pointer in sv to val. See SvIV_set .

    1. void SvSTASH_set(SV* sv, HV* val)
  • SvTAINT

    Taints an SV if tainting is enabled.

    1. void SvTAINT(SV* sv)
  • SvTAINTED

    Checks to see if an SV is tainted. Returns TRUE if it is, FALSE if not.

    1. bool SvTAINTED(SV* sv)
  • SvTAINTED_off

    Untaints an SV. Be very careful with this routine, as it short-circuits some of Perl's fundamental security features. XS module authors should not use this function unless they fully understand all the implications of unconditionally untainting the value. Untainting should be done in the standard perl fashion, via a carefully crafted regexp, rather than directly untainting variables.

    1. void SvTAINTED_off(SV* sv)
  • SvTAINTED_on

    Marks an SV as tainted if tainting is enabled.

    1. void SvTAINTED_on(SV* sv)
  • SvTRUE

    Returns a boolean indicating whether Perl would evaluate the SV as true or false. See SvOK() for a defined/undefined test. Does not handle 'get' magic.

    1. bool SvTRUE(SV* sv)
  • SvTYPE

    Returns the type of the SV. See svtype .

    1. svtype SvTYPE(SV* sv)
  • SvUOK

    Returns a boolean indicating whether the SV contains an unsigned integer.

    1. bool SvUOK(SV* sv)
  • SvUPGRADE

    Used to upgrade an SV to a more complex form. Uses sv_upgrade to perform the upgrade if necessary. See svtype .

    1. void SvUPGRADE(SV* sv, svtype type)
  • SvUTF8

    Returns a U32 value indicating whether the SV contains UTF-8 encoded data. Call this after SvPV() in case any call to string overloading updates the internal flag.

    1. U32 SvUTF8(SV* sv)
  • SvUTF8_off

    Unsets the UTF-8 status of an SV.

    1. void SvUTF8_off(SV *sv)
  • SvUTF8_on

    Turn on the UTF-8 status of an SV (the data is not changed, just the flag). Do not use frivolously.

    1. void SvUTF8_on(SV *sv)
  • SvUV

    Coerces the given SV to an unsigned integer and returns it. See SvUVx for a version which guarantees to evaluate sv only once.

    1. UV SvUV(SV* sv)
  • SvUVX

    Returns the raw value in the SV's UV slot, without checks or conversions. Only use when you are sure SvIOK is true. See also SvUV() .

    1. UV SvUVX(SV* sv)
  • SvUVx

    Coerces the given SV to an unsigned integer and returns it. Guarantees to sv only once. Only use this if sv is an expression with side effects, otherwise use the more efficient SvUV .

    1. UV SvUVx(SV* sv)
  • SvUV_nomg

    Like SvUV but doesn't process magic.

    1. UV SvUV_nomg(SV* sv)
  • SvUV_set

    Set the value of the UV pointer in sv to val. See SvIV_set .

    1. void SvUV_set(SV* sv, UV val)
  • SvVOK

    Returns a boolean indicating whether the SV contains a v-string.

    1. bool SvVOK(SV* sv)
  • sv_catpvn_nomg

    Like sv_catpvn but doesn't process magic.

    1. void sv_catpvn_nomg(SV* sv, const char* ptr, STRLEN len)
  • sv_catsv_nomg

    Like sv_catsv but doesn't process magic.

    1. void sv_catsv_nomg(SV* dsv, SV* ssv)
  • sv_derived_from

    Returns a boolean indicating whether the SV is derived from the specified class at the C level. To check derivation at the Perl level, call isa() as a normal Perl method.

    1. bool sv_derived_from(SV* sv, const char *const name)
  • sv_does

    Returns a boolean indicating whether the SV performs a specific, named role. The SV can be a Perl object or the name of a Perl class.

    1. bool sv_does(SV* sv, const char *const name)
  • sv_report_used

    Dump the contents of all SVs not yet freed. (Debugging aid).

    1. void sv_report_used()
  • sv_setsv_nomg

    Like sv_setsv but doesn't process magic.

    1. void sv_setsv_nomg(SV* dsv, SV* ssv)
  • sv_utf8_upgrade_nomg

    Like sv_utf8_upgrade, but doesn't do magic on sv

    1. STRLEN sv_utf8_upgrade_nomg(NN SV *sv)

SV-Body Allocation

  • looks_like_number

    Test if the content of an SV looks like a number (or is a number). Inf and Infinity are treated as numbers (so will not issue a non-numeric warning), even if your atof() doesn't grok them.

    1. I32 looks_like_number(SV *const sv)
  • newRV_noinc

    Creates an RV wrapper for an SV. The reference count for the original SV is not incremented.

    1. SV* newRV_noinc(SV *const sv)
  • newSV

    Creates a new SV. A non-zero len parameter indicates the number of bytes of preallocated string space the SV should have. An extra byte for a trailing NUL is also reserved. (SvPOK is not set for the SV even if string space is allocated.) The reference count for the new SV is set to 1.

    In 5.9.3, newSV() replaces the older NEWSV() API, and drops the first parameter, x, a debug aid which allowed callers to identify themselves. This aid has been superseded by a new build option, PERL_MEM_LOG (see PERL_MEM_LOG in perlhack). The older API is still there for use in XS modules supporting older perls.

    1. SV* newSV(const STRLEN len)
  • newSVhek

    Creates a new SV from the hash key structure. It will generate scalars that point to the shared string table where possible. Returns a new (undefined) SV if the hek is NULL.

    1. SV* newSVhek(const HEK *const hek)
  • newSViv

    Creates a new SV and copies an integer into it. The reference count for the SV is set to 1.

    1. SV* newSViv(const IV i)
  • newSVnv

    Creates a new SV and copies a floating point value into it. The reference count for the SV is set to 1.

    1. SV* newSVnv(const NV n)
  • newSVpv

    Creates a new SV and copies a string into it. The reference count for the SV is set to 1. If len is zero, Perl will compute the length using strlen(). For efficiency, consider using newSVpvn instead.

    1. SV* newSVpv(const char *const s, const STRLEN len)
  • newSVpvf

    Creates a new SV and initializes it with the string formatted like sprintf.

    1. SV* newSVpvf(const char *const pat, ...)
  • newSVpvn

    Creates a new SV and copies a string into it. The reference count for the SV is set to 1. Note that if len is zero, Perl will create a zero length string. You are responsible for ensuring that the source string is at least len bytes long. If the s argument is NULL the new SV will be undefined.

    1. SV* newSVpvn(const char *const s, const STRLEN len)
  • newSVpvn_flags

    Creates a new SV and copies a string into it. The reference count for the SV is set to 1. Note that if len is zero, Perl will create a zero length string. You are responsible for ensuring that the source string is at least len bytes long. If the s argument is NULL the new SV will be undefined. Currently the only flag bits accepted are SVf_UTF8 and SVs_TEMP . If SVs_TEMP is set, then sv2mortal() is called on the result before returning. If SVf_UTF8 is set, s is considered to be in UTF-8 and the SVf_UTF8 flag will be set on the new SV. newSVpvn_utf8() is a convenience wrapper for this function, defined as

    1. #define newSVpvn_utf8(s, len, u) \
    2. newSVpvn_flags((s), (len), (u) ? SVf_UTF8 : 0)
    3. SV* newSVpvn_flags(const char *const s, const STRLEN len, const U32 flags)
  • newSVpvn_share

    Creates a new SV with its SvPVX_const pointing to a shared string in the string table. If the string does not already exist in the table, it is created first. Turns on READONLY and FAKE. If the hash parameter is non-zero, that value is used; otherwise the hash is computed. The string's hash can be later be retrieved from the SV with the SvSHARED_HASH() macro. The idea here is that as the string table is used for shared hash keys these strings will have SvPVX_const == HeKEY and hash lookup will avoid string compare.

    1. SV* newSVpvn_share(const char* s, I32 len, U32 hash)
  • newSVpvs

    Like newSVpvn , but takes a literal string instead of a string/length pair.

    1. SV* newSVpvs(const char* s)
  • newSVpvs_flags

    Like newSVpvn_flags , but takes a literal string instead of a string/length pair.

    1. SV* newSVpvs_flags(const char* s, U32 flags)
  • newSVpvs_share

    Like newSVpvn_share , but takes a literal string instead of a string/length pair and omits the hash parameter.

    1. SV* newSVpvs_share(const char* s)
  • newSVrv

    Creates a new SV for the RV, rv , to point to. If rv is not an RV then it will be upgraded to one. If classname is non-null then the new SV will be blessed in the specified package. The new SV is returned and its reference count is 1.

    1. SV* newSVrv(SV *const rv, const char *const classname)
  • newSVsv

    Creates a new SV which is an exact duplicate of the original SV. (Uses sv_setsv ).

    1. SV* newSVsv(SV *const old)
  • newSVuv

    Creates a new SV and copies an unsigned integer into it. The reference count for the SV is set to 1.

    1. SV* newSVuv(const UV u)
  • newSV_type

    Creates a new SV, of the type specified. The reference count for the new SV is set to 1.

    1. SV* newSV_type(const svtype type)
  • sv_2bool

    This function is only called on magical items, and is only used by sv_true() or its macro equivalent.

    1. bool sv_2bool(SV *const sv)
  • sv_2cv

    Using various gambits, try to get a CV from an SV; in addition, try if possible to set *st and *gvp to the stash and GV associated with it. The flags in lref are passed to gv_fetchsv.

    1. CV* sv_2cv(SV* sv, HV **const st, GV **const gvp, const I32 lref)
  • sv_2io

    Using various gambits, try to get an IO from an SV: the IO slot if its a GV; or the recursive result if we're an RV; or the IO slot of the symbol named after the PV if we're a string.

    1. IO* sv_2io(SV *const sv)
  • sv_2iv_flags

    Return the integer value of an SV, doing any necessary string conversion. If flags includes SV_GMAGIC, does an mg_get() first. Normally used via the SvIV(sv) and SvIVx(sv) macros.

    1. IV sv_2iv_flags(SV *const sv, const I32 flags)
  • sv_2mortal

    Marks an existing SV as mortal. The SV will be destroyed "soon", either by an explicit call to FREETMPS, or by an implicit call at places such as statement boundaries. SvTEMP() is turned on which means that the SV's string buffer can be "stolen" if this SV is copied. See also sv_newmortal and sv_mortalcopy .

    1. SV* sv_2mortal(SV *const sv)
  • sv_2nv

    Return the num value of an SV, doing any necessary string or integer conversion, magic etc. Normally used via the SvNV(sv) and SvNVx(sv) macros.

    1. NV sv_2nv(SV *const sv)
  • sv_2pvbyte

    Return a pointer to the byte-encoded representation of the SV, and set *lp to its length. May cause the SV to be downgraded from UTF-8 as a side-effect.

    Usually accessed via the SvPVbyte macro.

    1. char* sv_2pvbyte(SV *const sv, STRLEN *const lp)
  • sv_2pvutf8

    Return a pointer to the UTF-8-encoded representation of the SV, and set *lp to its length. May cause the SV to be upgraded to UTF-8 as a side-effect.

    Usually accessed via the SvPVutf8 macro.

    1. char* sv_2pvutf8(SV *const sv, STRLEN *const lp)
  • sv_2pv_flags

    Returns a pointer to the string value of an SV, and sets *lp to its length. If flags includes SV_GMAGIC, does an mg_get() first. Coerces sv to a string if necessary. Normally invoked via the SvPV_flags macro. sv_2pv() and sv_2pv_nomg usually end up here too.

    1. char* sv_2pv_flags(SV *const sv, STRLEN *const lp, const I32 flags)
  • sv_2uv_flags

    Return the unsigned integer value of an SV, doing any necessary string conversion. If flags includes SV_GMAGIC, does an mg_get() first. Normally used via the SvUV(sv) and SvUVx(sv) macros.

    1. UV sv_2uv_flags(SV *const sv, const I32 flags)
  • sv_backoff

    Remove any string offset. You should normally use the SvOOK_off macro wrapper instead.

    1. int sv_backoff(SV *const sv)
  • sv_bless

    Blesses an SV into a specified package. The SV must be an RV. The package must be designated by its stash (see gv_stashpv() ). The reference count of the SV is unaffected.

    1. SV* sv_bless(SV *const sv, HV *const stash)
  • sv_catpv

    Concatenates the string onto the end of the string which is in the SV. If the SV has the UTF-8 status set, then the bytes appended should be valid UTF-8. Handles 'get' magic, but not 'set' magic. See sv_catpv_mg .

    1. void sv_catpv(SV *const sv, const char* ptr)
  • sv_catpvf

    Processes its arguments like sprintf and appends the formatted output to an SV. If the appended data contains "wide" characters (including, but not limited to, SVs with a UTF-8 PV formatted with %s, and characters >255 formatted with %c), the original SV might get upgraded to UTF-8. Handles 'get' magic, but not 'set' magic. See sv_catpvf_mg . If the original SV was UTF-8, the pattern should be valid UTF-8; if the original SV was bytes, the pattern should be too.

    1. void sv_catpvf(SV *const sv, const char *const pat, ...)
  • sv_catpvf_mg

    Like sv_catpvf , but also handles 'set' magic.

    1. void sv_catpvf_mg(SV *const sv, const char *const pat, ...)
  • sv_catpvn

    Concatenates the string onto the end of the string which is in the SV. The len indicates number of bytes to copy. If the SV has the UTF-8 status set, then the bytes appended should be valid UTF-8. Handles 'get' magic, but not 'set' magic. See sv_catpvn_mg .

    1. void sv_catpvn(SV *dsv, const char *sstr, STRLEN len)
  • sv_catpvn_flags

    Concatenates the string onto the end of the string which is in the SV. The len indicates number of bytes to copy. If the SV has the UTF-8 status set, then the bytes appended should be valid UTF-8. If flags has SV_GMAGIC bit set, will mg_get on dsv if appropriate, else not. sv_catpvn and sv_catpvn_nomg are implemented in terms of this function.

    1. void sv_catpvn_flags(SV *const dstr, const char *sstr, const STRLEN len, const I32 flags)
  • sv_catpvs

    Like sv_catpvn , but takes a literal string instead of a string/length pair.

    1. void sv_catpvs(SV* sv, const char* s)
  • sv_catpv_mg

    Like sv_catpv , but also handles 'set' magic.

    1. void sv_catpv_mg(SV *const sv, const char *const ptr)
  • sv_catsv

    Concatenates the string from SV ssv onto the end of the string in SV dsv . Modifies dsv but not ssv . Handles 'get' magic, but not 'set' magic. See sv_catsv_mg .

    1. void sv_catsv(SV *dstr, SV *sstr)
  • sv_catsv_flags

    Concatenates the string from SV ssv onto the end of the string in SV dsv . Modifies dsv but not ssv . If flags has SV_GMAGIC bit set, will mg_get on the SVs if appropriate, else not. sv_catsv and sv_catsv_nomg are implemented in terms of this function.

    1. void sv_catsv_flags(SV *const dsv, SV *const ssv, const I32 flags)
  • sv_chop

    Efficient removal of characters from the beginning of the string buffer. SvPOK(sv) must be true and the ptr must be a pointer to somewhere inside the string buffer. The ptr becomes the first character of the adjusted string. Uses the "OOK hack". Beware: after this function returns, ptr and SvPVX_const(sv) may no longer refer to the same chunk of data.

    1. void sv_chop(SV *const sv, const char *const ptr)
  • sv_clear

    Clear an SV: call any destructors, free up any memory used by the body, and free the body itself. The SV's head is not freed, although its type is set to all 1's so that it won't inadvertently be assumed to be live during global destruction etc. This function should only be called when REFCNT is zero. Most of the time you'll want to call sv_free() (or its macro wrapper SvREFCNT_dec ) instead.

    1. void sv_clear(SV *const sv)
  • sv_cmp

    Compares the strings in two SVs. Returns -1, 0, or 1 indicating whether the string in sv1 is less than, equal to, or greater than the string in sv2 . Is UTF-8 and 'use bytes' aware, handles get magic, and will coerce its args to strings if necessary. See also sv_cmp_locale .

    1. I32 sv_cmp(SV *const sv1, SV *const sv2)
  • sv_cmp_locale

    Compares the strings in two SVs in a locale-aware manner. Is UTF-8 and 'use bytes' aware, handles get magic, and will coerce its args to strings if necessary. See also sv_cmp .

    1. I32 sv_cmp_locale(SV *const sv1, SV *const sv2)
  • sv_collxfrm

    Add Collate Transform magic to an SV if it doesn't already have it.

    Any scalar variable may carry PERL_MAGIC_collxfrm magic that contains the scalar data of the variable, but transformed to such a format that a normal memory comparison can be used to compare the data according to the locale settings.

    1. char* sv_collxfrm(SV *const sv, STRLEN *const nxp)
  • sv_copypv

    Copies a stringified representation of the source SV into the destination SV. Automatically performs any necessary mg_get and coercion of numeric values into strings. Guaranteed to preserve UTF8 flag even from overloaded objects. Similar in nature to sv_2pv[_flags] but operates directly on an SV instead of just the string. Mostly uses sv_2pv_flags to do its work, except when that would lose the UTF-8'ness of the PV.

    1. void sv_copypv(SV *const dsv, SV *const ssv)
  • sv_dec

    Auto-decrement of the value in the SV, doing string to numeric conversion if necessary. Handles 'get' magic.

    1. void sv_dec(SV *const sv)
  • sv_eq

    Returns a boolean indicating whether the strings in the two SVs are identical. Is UTF-8 and 'use bytes' aware, handles get magic, and will coerce its args to strings if necessary.

    1. I32 sv_eq(SV* sv1, SV* sv2)
  • sv_force_normal_flags

    Undo various types of fakery on an SV: if the PV is a shared string, make a private copy; if we're a ref, stop refing; if we're a glob, downgrade to an xpvmg; if we're a copy-on-write scalar, this is the on-write time when we do the copy, and is also used locally. If SV_COW_DROP_PV is set then a copy-on-write scalar drops its PV buffer (if any) and becomes SvPOK_off rather than making a copy. (Used where this scalar is about to be set to some other value.) In addition, the flags parameter gets passed to sv_unref_flags() when unrefing. sv_force_normal calls this function with flags set to 0.

    1. void sv_force_normal_flags(SV *const sv, const U32 flags)
  • sv_free

    Decrement an SV's reference count, and if it drops to zero, call sv_clear to invoke destructors and free up any memory used by the body; finally, deallocate the SV's head itself. Normally called via a wrapper macro SvREFCNT_dec .

    1. void sv_free(SV *const sv)
  • sv_gets

    Get a line from the filehandle and store it into the SV, optionally appending to the currently-stored string.

    1. char* sv_gets(SV *const sv, PerlIO *const fp, I32 append)
  • sv_grow

    Expands the character buffer in the SV. If necessary, uses sv_unref and upgrades the SV to SVt_PV . Returns a pointer to the character buffer. Use the SvGROW wrapper instead.

    1. char* sv_grow(SV *const sv, STRLEN newlen)
  • sv_inc

    Auto-increment of the value in the SV, doing string to numeric conversion if necessary. Handles 'get' magic.

    1. void sv_inc(SV *const sv)
  • sv_insert

    Inserts a string at the specified offset/length within the SV. Similar to the Perl substr() function. Handles get magic.

    1. void sv_insert(SV *const bigstr, const STRLEN offset, const STRLEN len, const char *const little, const STRLEN littlelen)
  • sv_insert_flags

    Same as sv_insert , but the extra flags are passed the SvPV_force_flags that applies to bigstr .

    1. void sv_insert_flags(SV *const bigstr, const STRLEN offset, const STRLEN len, const char *const little, const STRLEN littlelen, const U32 flags)
  • sv_isa

    Returns a boolean indicating whether the SV is blessed into the specified class. This does not check for subtypes; use sv_derived_from to verify an inheritance relationship.

    1. int sv_isa(SV* sv, const char *const name)
  • sv_isobject

    Returns a boolean indicating whether the SV is an RV pointing to a blessed object. If the SV is not an RV, or if the object is not blessed, then this will return false.

    1. int sv_isobject(SV* sv)
  • sv_len

    Returns the length of the string in the SV. Handles magic and type coercion. See also SvCUR , which gives raw access to the xpv_cur slot.

    1. STRLEN sv_len(SV *const sv)
  • sv_len_utf8

    Returns the number of characters in the string in an SV, counting wide UTF-8 bytes as a single character. Handles magic and type coercion.

    1. STRLEN sv_len_utf8(SV *const sv)
  • sv_magic

    Adds magic to an SV. First upgrades sv to type SVt_PVMG if necessary, then adds a new magic item of type how to the head of the magic list.

    See sv_magicext (which sv_magic now calls) for a description of the handling of the name and namlen arguments.

    You need to use sv_magicext to add magic to SvREADONLY SVs and also to add more than one instance of the same 'how'.

    1. void sv_magic(SV *const sv, SV *const obj, const int how, const char *const name, const I32 namlen)
  • sv_magicext

    Adds magic to an SV, upgrading it if necessary. Applies the supplied vtable and returns a pointer to the magic added.

    Note that sv_magicext will allow things that sv_magic will not. In particular, you can add magic to SvREADONLY SVs, and add more than one instance of the same 'how'.

    If namlen is greater than zero then a savepvn copy of name is stored, if namlen is zero then name is stored as-is and - as another special case - if (name && namlen == HEf_SVKEY) then name is assumed to contain an SV* and is stored as-is with its REFCNT incremented.

    (This is now used as a subroutine by sv_magic .)

    1. MAGIC * sv_magicext(SV *const sv, SV *const obj, const int how, const MGVTBL *const vtbl, const char *const name, const I32 namlen)
  • sv_mortalcopy

    Creates a new SV which is a copy of the original SV (using sv_setsv ). The new SV is marked as mortal. It will be destroyed "soon", either by an explicit call to FREETMPS, or by an implicit call at places such as statement boundaries. See also sv_newmortal and sv_2mortal .

    1. SV* sv_mortalcopy(SV *const oldsv)
  • sv_newmortal

    Creates a new null SV which is mortal. The reference count of the SV is set to 1. It will be destroyed "soon", either by an explicit call to FREETMPS, or by an implicit call at places such as statement boundaries. See also sv_mortalcopy and sv_2mortal .

    1. SV* sv_newmortal()
  • sv_newref

    Increment an SV's reference count. Use the SvREFCNT_inc() wrapper instead.

    1. SV* sv_newref(SV *const sv)
  • sv_pos_b2u

    Converts the value pointed to by offsetp from a count of bytes from the start of the string, to a count of the equivalent number of UTF-8 chars. Handles magic and type coercion.

    1. void sv_pos_b2u(SV *const sv, I32 *const offsetp)
  • sv_pos_u2b

    Converts the value pointed to by offsetp from a count of UTF-8 chars from the start of the string, to a count of the equivalent number of bytes; if lenp is non-zero, it does the same to lenp, but this time starting from the offset, rather than from the start of the string. Handles magic and type coercion.

    Use sv_pos_u2b_flags in preference, which correctly handles strings longer than 2Gb.

    1. void sv_pos_u2b(SV *const sv, I32 *const offsetp, I32 *const lenp)
  • sv_pos_u2b_flags

    Converts the value pointed to by offsetp from a count of UTF-8 chars from the start of the string, to a count of the equivalent number of bytes; if lenp is non-zero, it does the same to lenp, but this time starting from the offset, rather than from the start of the string. Handles type coercion. flags is passed to SvPV_flags , and usually should be SV_GMAGIC|SV_CONST_RETURN to handle magic.

    1. STRLEN sv_pos_u2b_flags(SV *const sv, STRLEN uoffset, STRLEN *const lenp, U32 flags)
  • sv_pvbyten_force

    The backend for the SvPVbytex_force macro. Always use the macro instead.

    1. char* sv_pvbyten_force(SV *const sv, STRLEN *const lp)
  • sv_pvn_force

    Get a sensible string out of the SV somehow. A private implementation of the SvPV_force macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    1. char* sv_pvn_force(SV* sv, STRLEN* lp)
  • sv_pvn_force_flags

    Get a sensible string out of the SV somehow. If flags has SV_GMAGIC bit set, will mg_get on sv if appropriate, else not. sv_pvn_force and sv_pvn_force_nomg are implemented in terms of this function. You normally want to use the various wrapper macros instead: see SvPV_force and SvPV_force_nomg

    1. char* sv_pvn_force_flags(SV *const sv, STRLEN *const lp, const I32 flags)
  • sv_pvutf8n_force

    The backend for the SvPVutf8x_force macro. Always use the macro instead.

    1. char* sv_pvutf8n_force(SV *const sv, STRLEN *const lp)
  • sv_reftype

    Returns a string describing what the SV is a reference to.

    1. const char* sv_reftype(const SV *const sv, const int ob)
  • sv_replace

    Make the first argument a copy of the second, then delete the original. The target SV physically takes over ownership of the body of the source SV and inherits its flags; however, the target keeps any magic it owns, and any magic in the source is discarded. Note that this is a rather specialist SV copying operation; most of the time you'll want to use sv_setsv or one of its many macro front-ends.

    1. void sv_replace(SV *const sv, SV *const nsv)
  • sv_reset

    Underlying implementation for the reset Perl function. Note that the perl-level function is vaguely deprecated.

    1. void sv_reset(const char* s, HV *const stash)
  • sv_rvweaken

    Weaken a reference: set the SvWEAKREF flag on this RV; give the referred-to SV PERL_MAGIC_backref magic if it hasn't already; and push a back-reference to this RV onto the array of backreferences associated with that magic. If the RV is magical, set magic will be called after the RV is cleared.

    1. SV* sv_rvweaken(SV *const sv)
  • sv_setiv

    Copies an integer into the given SV, upgrading first if necessary. Does not handle 'set' magic. See also sv_setiv_mg .

    1. void sv_setiv(SV *const sv, const IV num)
  • sv_setiv_mg

    Like sv_setiv , but also handles 'set' magic.

    1. void sv_setiv_mg(SV *const sv, const IV i)
  • sv_setnv

    Copies a double into the given SV, upgrading first if necessary. Does not handle 'set' magic. See also sv_setnv_mg .

    1. void sv_setnv(SV *const sv, const NV num)
  • sv_setnv_mg

    Like sv_setnv , but also handles 'set' magic.

    1. void sv_setnv_mg(SV *const sv, const NV num)
  • sv_setpv

    Copies a string into an SV. The string must be null-terminated. Does not handle 'set' magic. See sv_setpv_mg .

    1. void sv_setpv(SV *const sv, const char *const ptr)
  • sv_setpvf

    Works like sv_catpvf but copies the text into the SV instead of appending it. Does not handle 'set' magic. See sv_setpvf_mg .

    1. void sv_setpvf(SV *const sv, const char *const pat, ...)
  • sv_setpvf_mg

    Like sv_setpvf , but also handles 'set' magic.

    1. void sv_setpvf_mg(SV *const sv, const char *const pat, ...)
  • sv_setpviv

    Copies an integer into the given SV, also updating its string value. Does not handle 'set' magic. See sv_setpviv_mg .

    1. void sv_setpviv(SV *const sv, const IV num)
  • sv_setpviv_mg

    Like sv_setpviv , but also handles 'set' magic.

    1. void sv_setpviv_mg(SV *const sv, const IV iv)
  • sv_setpvn

    Copies a string into an SV. The len parameter indicates the number of bytes to be copied. If the ptr argument is NULL the SV will become undefined. Does not handle 'set' magic. See sv_setpvn_mg .

    1. void sv_setpvn(SV *const sv, const char *const ptr, const STRLEN len)
  • sv_setpvn_mg

    Like sv_setpvn , but also handles 'set' magic.

    1. void sv_setpvn_mg(SV *const sv, const char *const ptr, const STRLEN len)
  • sv_setpvs

    Like sv_setpvn , but takes a literal string instead of a string/length pair.

    1. void sv_setpvs(SV* sv, const char* s)
  • sv_setpv_mg

    Like sv_setpv , but also handles 'set' magic.

    1. void sv_setpv_mg(SV *const sv, const char *const ptr)
  • sv_setref_iv

    Copies an integer into a new SV, optionally blessing the SV. The rv argument will be upgraded to an RV. That RV will be modified to point to the new SV. The classname argument indicates the package for the blessing. Set classname to NULL to avoid the blessing. The new SV will have a reference count of 1, and the RV will be returned.

    1. SV* sv_setref_iv(SV *const rv, const char *const classname, const IV iv)
  • sv_setref_nv

    Copies a double into a new SV, optionally blessing the SV. The rv argument will be upgraded to an RV. That RV will be modified to point to the new SV. The classname argument indicates the package for the blessing. Set classname to NULL to avoid the blessing. The new SV will have a reference count of 1, and the RV will be returned.

    1. SV* sv_setref_nv(SV *const rv, const char *const classname, const NV nv)
  • sv_setref_pv

    Copies a pointer into a new SV, optionally blessing the SV. The rv argument will be upgraded to an RV. That RV will be modified to point to the new SV. If the pv argument is NULL then PL_sv_undef will be placed into the SV. The classname argument indicates the package for the blessing. Set classname to NULL to avoid the blessing. The new SV will have a reference count of 1, and the RV will be returned.

    Do not use with other Perl types such as HV, AV, SV, CV, because those objects will become corrupted by the pointer copy process.

    Note that sv_setref_pvn copies the string while this copies the pointer.

    1. SV* sv_setref_pv(SV *const rv, const char *const classname, void *const pv)
  • sv_setref_pvn

    Copies a string into a new SV, optionally blessing the SV. The length of the string must be specified with n . The rv argument will be upgraded to an RV. That RV will be modified to point to the new SV. The classname argument indicates the package for the blessing. Set classname to NULL to avoid the blessing. The new SV will have a reference count of 1, and the RV will be returned.

    Note that sv_setref_pv copies the pointer while this copies the string.

    1. SV* sv_setref_pvn(SV *const rv, const char *const classname, const char *const pv, const STRLEN n)
  • sv_setref_uv

    Copies an unsigned integer into a new SV, optionally blessing the SV. The rv argument will be upgraded to an RV. That RV will be modified to point to the new SV. The classname argument indicates the package for the blessing. Set classname to NULL to avoid the blessing. The new SV will have a reference count of 1, and the RV will be returned.

    1. SV* sv_setref_uv(SV *const rv, const char *const classname, const UV uv)
  • sv_setsv

    Copies the contents of the source SV ssv into the destination SV dsv . The source SV may be destroyed if it is mortal, so don't use this function if the source SV needs to be reused. Does not handle 'set' magic. Loosely speaking, it performs a copy-by-value, obliterating any previous content of the destination.

    You probably want to use one of the assortment of wrappers, such as SvSetSV , SvSetSV_nosteal , SvSetMagicSV and SvSetMagicSV_nosteal .

    1. void sv_setsv(SV *dstr, SV *sstr)
  • sv_setsv_flags

    Copies the contents of the source SV ssv into the destination SV dsv . The source SV may be destroyed if it is mortal, so don't use this function if the source SV needs to be reused. Does not handle 'set' magic. Loosely speaking, it performs a copy-by-value, obliterating any previous content of the destination. If the flags parameter has the SV_GMAGIC bit set, will mg_get on ssv if appropriate, else not. If the flags parameter has the NOSTEAL bit set then the buffers of temps will not be stolen. <sv_setsv> and sv_setsv_nomg are implemented in terms of this function.

    You probably want to use one of the assortment of wrappers, such as SvSetSV , SvSetSV_nosteal , SvSetMagicSV and SvSetMagicSV_nosteal .

    This is the primary function for copying scalars, and most other copy-ish functions and macros use this underneath.

    1. void sv_setsv_flags(SV *dstr, SV *sstr, const I32 flags)
  • sv_setsv_mg

    Like sv_setsv , but also handles 'set' magic.

    1. void sv_setsv_mg(SV *const dstr, SV *const sstr)
  • sv_setuv

    Copies an unsigned integer into the given SV, upgrading first if necessary. Does not handle 'set' magic. See also sv_setuv_mg .

    1. void sv_setuv(SV *const sv, const UV num)
  • sv_setuv_mg

    Like sv_setuv , but also handles 'set' magic.

    1. void sv_setuv_mg(SV *const sv, const UV u)
  • sv_tainted

    Test an SV for taintedness. Use SvTAINTED instead. bool sv_tainted(SV *const sv)

  • sv_true

    Returns true if the SV has a true value by Perl's rules. Use the SvTRUE macro instead, which may call sv_true() or may instead use an in-line version.

    1. I32 sv_true(SV *const sv)
  • sv_unmagic

    Removes all magic of type type from an SV.

    1. int sv_unmagic(SV *const sv, const int type)
  • sv_unref_flags

    Unsets the RV status of the SV, and decrements the reference count of whatever was being referenced by the RV. This can almost be thought of as a reversal of newSVrv . The cflags argument can contain SV_IMMEDIATE_UNREF to force the reference count to be decremented (otherwise the decrementing is conditional on the reference count being different from one or the reference being a readonly SV). See SvROK_off .

    1. void sv_unref_flags(SV *const ref, const U32 flags)
  • sv_untaint

    Untaint an SV. Use SvTAINTED_off instead. void sv_untaint(SV *const sv)

  • sv_upgrade

    Upgrade an SV to a more complex form. Generally adds a new body type to the SV, then copies across as much information as possible from the old body. You generally want to use the SvUPGRADE macro wrapper. See also svtype .

    1. void sv_upgrade(SV *const sv, svtype new_type)
  • sv_usepvn_flags

    Tells an SV to use ptr to find its string value. Normally the string is stored inside the SV but sv_usepvn allows the SV to use an outside string. The ptr should point to memory that was allocated by malloc . The string length, len , must be supplied. By default this function will realloc (i.e. move) the memory pointed to by ptr , so that pointer should not be freed or used by the programmer after giving it to sv_usepvn, and neither should any pointers from "behind" that pointer (e.g. ptr + 1) be used.

    If flags & SV_SMAGIC is true, will call SvSETMAGIC. If flags & SV_HAS_TRAILING_NUL is true, then ptr[len] must be NUL, and the realloc will be skipped. (i.e. the buffer is actually at least 1 byte longer than len , and already meets the requirements for storing in SvPVX )

    1. void sv_usepvn_flags(SV *const sv, char* ptr, const STRLEN len, const U32 flags)
  • sv_utf8_decode

    If the PV of the SV is an octet sequence in UTF-8 and contains a multiple-byte character, the SvUTF8 flag is turned on so that it looks like a character. If the PV contains only single-byte characters, the SvUTF8 flag stays being off. Scans PV for validity and returns false if the PV is invalid UTF-8.

    NOTE: this function is experimental and may change or be removed without notice.

    1. bool sv_utf8_decode(SV *const sv)
  • sv_utf8_downgrade

    Attempts to convert the PV of an SV from characters to bytes. If the PV contains a character that cannot fit in a byte, this conversion will fail; in this case, either returns false or, if fail_ok is not true, croaks.

    This is not as a general purpose Unicode to byte encoding interface: use the Encode extension for that.

    NOTE: this function is experimental and may change or be removed without notice.

    1. bool sv_utf8_downgrade(SV *const sv, const bool fail_ok)
  • sv_utf8_encode

    Converts the PV of an SV to UTF-8, but then turns the SvUTF8 flag off so that it looks like octets again.

    1. void sv_utf8_encode(SV *const sv)
  • sv_utf8_upgrade

    Converts the PV of an SV to its UTF-8-encoded form. Forces the SV to string form if it is not already. Will mg_get on sv if appropriate. Always sets the SvUTF8 flag to avoid future validity checks even if the whole string is the same in UTF-8 as not. Returns the number of bytes in the converted string

    This is not as a general purpose byte encoding to Unicode interface: use the Encode extension for that.

    1. STRLEN sv_utf8_upgrade(SV *sv)
  • sv_utf8_upgrade_flags

    Converts the PV of an SV to its UTF-8-encoded form. Forces the SV to string form if it is not already. Always sets the SvUTF8 flag to avoid future validity checks even if all the bytes are invariant in UTF-8. If flags has SV_GMAGIC bit set, will mg_get on sv if appropriate, else not. Returns the number of bytes in the converted string sv_utf8_upgrade and sv_utf8_upgrade_nomg are implemented in terms of this function.

    This is not as a general purpose byte encoding to Unicode interface: use the Encode extension for that.

    1. STRLEN sv_utf8_upgrade_flags(SV *const sv, const I32 flags)
  • sv_utf8_upgrade_nomg

    Like sv_utf8_upgrade, but doesn't do magic on sv

    1. STRLEN sv_utf8_upgrade_nomg(SV *sv)
  • sv_vcatpvf

    Processes its arguments like vsprintf and appends the formatted output to an SV. Does not handle 'set' magic. See sv_vcatpvf_mg .

    Usually used via its frontend sv_catpvf .

    1. void sv_vcatpvf(SV *const sv, const char *const pat, va_list *const args)
  • sv_vcatpvfn

    Processes its arguments like vsprintf and appends the formatted output to an SV. Uses an array of SVs if the C style variable argument list is missing (NULL). When running with taint checks enabled, indicates via maybe_tainted if results are untrustworthy (often due to the use of locales).

    Usually used via one of its frontends sv_vcatpvf and sv_vcatpvf_mg .

    1. void sv_vcatpvfn(SV *const sv, const char *const pat, const STRLEN patlen, va_list *const args, SV **const svargs, const I32 svmax, bool *const maybe_tainted)
  • sv_vcatpvf_mg

    Like sv_vcatpvf , but also handles 'set' magic.

    Usually used via its frontend sv_catpvf_mg .

    1. void sv_vcatpvf_mg(SV *const sv, const char *const pat, va_list *const args)
  • sv_vsetpvf

    Works like sv_vcatpvf but copies the text into the SV instead of appending it. Does not handle 'set' magic. See sv_vsetpvf_mg .

    Usually used via its frontend sv_setpvf .

    1. void sv_vsetpvf(SV *const sv, const char *const pat, va_list *const args)
  • sv_vsetpvfn

    Works like sv_vcatpvfn but copies the text into the SV instead of appending it.

    Usually used via one of its frontends sv_vsetpvf and sv_vsetpvf_mg .

    1. void sv_vsetpvfn(SV *const sv, const char *const pat, const STRLEN patlen, va_list *const args, SV **const svargs, const I32 svmax, bool *const maybe_tainted)
  • sv_vsetpvf_mg

    Like sv_vsetpvf , but also handles 'set' magic.

    Usually used via its frontend sv_setpvf_mg .

    1. void sv_vsetpvf_mg(SV *const sv, const char *const pat, va_list *const args)

Unicode Support

  • bytes_from_utf8

    Converts a string s of length len from UTF-8 into native byte encoding. Unlike utf8_to_bytes but like bytes_to_utf8 , returns a pointer to the newly-created string, and updates len to contain the new length. Returns the original string if no conversion occurs, len is unchanged. Do nothing if is_utf8 points to 0. Sets is_utf8 to 0 if s is converted or consisted entirely of characters that are invariant in utf8 (i.e., US-ASCII on non-EBCDIC machines).

    NOTE: this function is experimental and may change or be removed without notice.

    1. U8* bytes_from_utf8(const U8 *s, STRLEN *len, bool *is_utf8)
  • bytes_to_utf8

    Converts a string s of length len from the native encoding into UTF-8. Returns a pointer to the newly-created string, and sets len to reflect the new length.

    A NUL character will be written after the end of the string.

    If you want to convert to UTF-8 from encodings other than the native (Latin1 or EBCDIC), see sv_recode_to_utf8().

    NOTE: this function is experimental and may change or be removed without notice.

    1. U8* bytes_to_utf8(const U8 *s, STRLEN *len)
  • ibcmp_utf8

    Return true if the strings s1 and s2 differ case-insensitively, false if not (if they are equal case-insensitively). If u1 is true, the string s1 is assumed to be in UTF-8-encoded Unicode. If u2 is true, the string s2 is assumed to be in UTF-8-encoded Unicode. If u1 or u2 are false, the respective string is assumed to be in native 8-bit encoding.

    If the pe1 and pe2 are non-NULL, the scanning pointers will be copied in there (they will point at the beginning of the next character). If the pointers behind pe1 or pe2 are non-NULL, they are the end pointers beyond which scanning will not continue under any circumstances. If the byte lengths l1 and l2 are non-zero, s1+l1 and s2+l2 will be used as goal end pointers that will also stop the scan, and which qualify towards defining a successful match: all the scans that define an explicit length must reach their goal pointers for a match to succeed).

    For case-insensitiveness, the "casefolding" of Unicode is used instead of upper/lowercasing both the characters, see http://www.unicode.org/unicode/reports/tr21/ (Case Mappings).

    1. I32 ibcmp_utf8(const char *s1, char **pe1, UV l1, bool u1, const char *s2, char **pe2, UV l2, bool u2)
  • is_ascii_string

    Returns true if first len bytes of the given string are ASCII (i.e. none of them even raise the question of UTF-8-ness).

    See also is_utf8_string(), is_utf8_string_loclen(), and is_utf8_string_loc().

    1. bool is_ascii_string(const U8 *s, STRLEN len)
  • is_utf8_char

    Tests if some arbitrary number of bytes begins in a valid UTF-8 character. Note that an INVARIANT (i.e. ASCII on non-EBCDIC machines) character is a valid UTF-8 character. The actual number of bytes in the UTF-8 character will be returned if it is valid, otherwise 0.

    1. STRLEN is_utf8_char(const U8 *s)
  • is_utf8_string

    Returns true if first len bytes of the given string form a valid UTF-8 string, false otherwise. Note that 'a valid UTF-8 string' does not mean 'a string that contains code points above 0x7F encoded in UTF-8' because a valid ASCII string is a valid UTF-8 string.

    See also is_ascii_string(), is_utf8_string_loclen(), and is_utf8_string_loc().

    1. bool is_utf8_string(const U8 *s, STRLEN len)
  • is_utf8_string_loc

    Like is_utf8_string() but stores the location of the failure (in the case of "utf8ness failure") or the location s+len (in the case of "utf8ness success") in the ep .

    See also is_utf8_string_loclen() and is_utf8_string().

    1. bool is_utf8_string_loc(const U8 *s, STRLEN len, const U8 **p)
  • is_utf8_string_loclen

    Like is_utf8_string() but stores the location of the failure (in the case of "utf8ness failure") or the location s+len (in the case of "utf8ness success") in the ep , and the number of UTF-8 encoded characters in the el .

    See also is_utf8_string_loc() and is_utf8_string().

    1. bool is_utf8_string_loclen(const U8 *s, STRLEN len, const U8 **ep, STRLEN *el)
  • pv_uni_display

    Build to the scalar dsv a displayable version of the string spv, length len, the displayable version being at most pvlim bytes long (if longer, the rest is truncated and "..." will be appended).

    The flags argument can have UNI_DISPLAY_ISPRINT set to display isPRINT()able characters as themselves, UNI_DISPLAY_BACKSLASH to display the \\[nrfta\\] as the backslashed versions (like '\n') (UNI_DISPLAY_BACKSLASH is preferred over UNI_DISPLAY_ISPRINT for \\). UNI_DISPLAY_QQ (and its alias UNI_DISPLAY_REGEX) have both UNI_DISPLAY_BACKSLASH and UNI_DISPLAY_ISPRINT turned on.

    The pointer to the PV of the dsv is returned.

    1. char* pv_uni_display(SV *dsv, const U8 *spv, STRLEN len, STRLEN pvlim, UV flags)
  • sv_cat_decode

    The encoding is assumed to be an Encode object, the PV of the ssv is assumed to be octets in that encoding and decoding the input starts from the position which (PV + *offset) pointed to. The dsv will be concatenated the decoded UTF-8 string from ssv. Decoding will terminate when the string tstr appears in decoding output or the input ends on the PV of the ssv. The value which the offset points will be modified to the last input position on the ssv.

    Returns TRUE if the terminator was found, else returns FALSE.

    1. bool sv_cat_decode(SV* dsv, SV *encoding, SV *ssv, int *offset, char* tstr, int tlen)
  • sv_recode_to_utf8

    The encoding is assumed to be an Encode object, on entry the PV of the sv is assumed to be octets in that encoding, and the sv will be converted into Unicode (and UTF-8).

    If the sv already is UTF-8 (or if it is not POK), or if the encoding is not a reference, nothing is done to the sv. If the encoding is not an Encode::XS Encoding object, bad things will happen. (See lib/encoding.pm and Encode).

    The PV of the sv is returned.

    1. char* sv_recode_to_utf8(SV* sv, SV *encoding)
  • sv_uni_display

    Build to the scalar dsv a displayable version of the scalar sv, the displayable version being at most pvlim bytes long (if longer, the rest is truncated and "..." will be appended).

    The flags argument is as in pv_uni_display().

    The pointer to the PV of the dsv is returned.

    1. char* sv_uni_display(SV *dsv, SV *ssv, STRLEN pvlim, UV flags)
  • to_utf8_case

    The "p" contains the pointer to the UTF-8 string encoding the character that is being converted.

    The "ustrp" is a pointer to the character buffer to put the conversion result to. The "lenp" is a pointer to the length of the result.

    The "swashp" is a pointer to the swash to use.

    Both the special and normal mappings are stored lib/unicore/To/Foo.pl, and loaded by SWASHNEW, using lib/utf8_heavy.pl. The special (usually, but not always, a multicharacter mapping), is tried first.

    The "special" is a string like "utf8::ToSpecLower", which means the hash %utf8::ToSpecLower. The access to the hash is through Perl_to_utf8_case().

    The "normal" is a string like "ToLower" which means the swash %utf8::ToLower.

    1. UV to_utf8_case(const U8 *p, U8* ustrp, STRLEN *lenp, SV **swashp, const char *normal, const char *special)
  • to_utf8_fold

    Convert the UTF-8 encoded character at p to its foldcase version and store that in UTF-8 in ustrp and its length in bytes in lenp. Note that the ustrp needs to be at least UTF8_MAXBYTES_CASE+1 bytes since the foldcase version may be longer than the original character (up to three characters).

    The first character of the foldcased version is returned (but note, as explained above, that there may be more.)

    1. UV to_utf8_fold(const U8 *p, U8* ustrp, STRLEN *lenp)
  • to_utf8_lower

    Convert the UTF-8 encoded character at p to its lowercase version and store that in UTF-8 in ustrp and its length in bytes in lenp. Note that the ustrp needs to be at least UTF8_MAXBYTES_CASE+1 bytes since the lowercase version may be longer than the original character.

    The first character of the lowercased version is returned (but note, as explained above, that there may be more.)

    1. UV to_utf8_lower(const U8 *p, U8* ustrp, STRLEN *lenp)
  • to_utf8_title

    Convert the UTF-8 encoded character at p to its titlecase version and store that in UTF-8 in ustrp and its length in bytes in lenp. Note that the ustrp needs to be at least UTF8_MAXBYTES_CASE+1 bytes since the titlecase version may be longer than the original character.

    The first character of the titlecased version is returned (but note, as explained above, that there may be more.)

    1. UV to_utf8_title(const U8 *p, U8* ustrp, STRLEN *lenp)
  • to_utf8_upper

    Convert the UTF-8 encoded character at p to its uppercase version and store that in UTF-8 in ustrp and its length in bytes in lenp. Note that the ustrp needs to be at least UTF8_MAXBYTES_CASE+1 bytes since the uppercase version may be longer than the original character.

    The first character of the uppercased version is returned (but note, as explained above, that there may be more.)

    1. UV to_utf8_upper(const U8 *p, U8* ustrp, STRLEN *lenp)
  • utf8n_to_uvchr

    flags

    Returns the native character value of the first character in the string s which is assumed to be in UTF-8 encoding; retlen will be set to the length, in bytes, of that character.

    Allows length and flags to be passed to low level routine.

    1. UV utf8n_to_uvchr(const U8 *s, STRLEN curlen, STRLEN *retlen, U32 flags)
  • utf8n_to_uvuni

    Bottom level UTF-8 decode routine. Returns the Unicode code point value of the first character in the string s which is assumed to be in UTF-8 encoding and no longer than curlen ; retlen will be set to the length, in bytes, of that character.

    If s does not point to a well-formed UTF-8 character, the behaviour is dependent on the value of flags : if it contains UTF8_CHECK_ONLY, it is assumed that the caller will raise a warning, and this function will silently just set retlen to -1 and return zero. If the flags does not contain UTF8_CHECK_ONLY, warnings about malformations will be given, retlen will be set to the expected length of the UTF-8 character in bytes, and zero will be returned.

    The flags can also contain various flags to allow deviations from the strict UTF-8 encoding (see utf8.h).

    Most code should use utf8_to_uvchr() rather than call this directly.

    1. UV utf8n_to_uvuni(const U8 *s, STRLEN curlen, STRLEN *retlen, U32 flags)
  • utf8_distance

    Returns the number of UTF-8 characters between the UTF-8 pointers a and b .

    WARNING: use only if you *know* that the pointers point inside the same UTF-8 buffer.

    1. IV utf8_distance(const U8 *a, const U8 *b)
  • utf8_hop

    Return the UTF-8 pointer s displaced by off characters, either forward or backward.

    WARNING: do not use the following unless you *know* off is within the UTF-8 data pointed to by s *and* that on entry s is aligned on the first byte of character or just after the last byte of a character.

    1. U8* utf8_hop(const U8 *s, I32 off)
  • utf8_length

    Return the length of the UTF-8 char encoded string s in characters. Stops at e (inclusive). If e < s or if the scan would end up past e , croaks.

    1. STRLEN utf8_length(const U8* s, const U8 *e)
  • utf8_to_bytes

    Converts a string s of length len from UTF-8 into native byte encoding. Unlike bytes_to_utf8 , this over-writes the original string, and updates len to contain the new length. Returns zero on failure, setting len to -1.

    If you need a copy of the string, see bytes_from_utf8 .

    NOTE: this function is experimental and may change or be removed without notice.

    1. U8* utf8_to_bytes(U8 *s, STRLEN *len)
  • utf8_to_uvchr

    Returns the native character value of the first character in the string s which is assumed to be in UTF-8 encoding; retlen will be set to the length, in bytes, of that character.

    If s does not point to a well-formed UTF-8 character, zero is returned and retlen is set, if possible, to -1.

    1. UV utf8_to_uvchr(const U8 *s, STRLEN *retlen)
  • utf8_to_uvuni

    Returns the Unicode code point of the first character in the string s which is assumed to be in UTF-8 encoding; retlen will be set to the length, in bytes, of that character.

    This function should only be used when the returned UV is considered an index into the Unicode semantic tables (e.g. swashes).

    If s does not point to a well-formed UTF-8 character, zero is returned and retlen is set, if possible, to -1.

    1. UV utf8_to_uvuni(const U8 *s, STRLEN *retlen)
  • uvchr_to_utf8

    Adds the UTF-8 representation of the Native codepoint uv to the end of the string d ; d should be have at least UTF8_MAXBYTES+1 free bytes available. The return value is the pointer to the byte after the end of the new character. In other words,

    1. d = uvchr_to_utf8(d, uv);

    is the recommended wide native character-aware way of saying

    1. *(d++) = uv;
    2. U8* uvchr_to_utf8(U8 *d, UV uv)
  • uvuni_to_utf8_flags

    Adds the UTF-8 representation of the Unicode codepoint uv to the end of the string d ; d should be have at least UTF8_MAXBYTES+1 free bytes available. The return value is the pointer to the byte after the end of the new character. In other words,

    1. d = uvuni_to_utf8_flags(d, uv, flags);

    or, in most cases,

    1. d = uvuni_to_utf8(d, uv);

    (which is equivalent to)

    1. d = uvuni_to_utf8_flags(d, uv, 0);

    is the recommended Unicode-aware way of saying

    1. *(d++) = uv;
    2. U8* uvuni_to_utf8_flags(U8 *d, UV uv, UV flags)

Variables created by xsubpp and xsubpp internal functions

  • ax

    Variable which is setup by xsubpp to indicate the stack base offset, used by the ST , XSprePUSH and XSRETURN macros. The dMARK macro must be called prior to setup the MARK variable.

    1. I32 ax
  • CLASS

    Variable which is setup by xsubpp to indicate the class name for a C++ XS constructor. This is always a char* . See THIS .

    1. char* CLASS
  • dAX

    Sets up the ax variable. This is usually handled automatically by xsubpp by calling dXSARGS .

    1. dAX;
  • dAXMARK

    Sets up the ax variable and stack marker variable mark . This is usually handled automatically by xsubpp by calling dXSARGS .

    1. dAXMARK;
  • dITEMS

    Sets up the items variable. This is usually handled automatically by xsubpp by calling dXSARGS .

    1. dITEMS;
  • dUNDERBAR

    Sets up the padoff_du variable for an XSUB that wishes to use UNDERBAR .

    1. dUNDERBAR;
  • dXSARGS

    Sets up stack and mark pointers for an XSUB, calling dSP and dMARK. Sets up the ax and items variables by calling dAX and dITEMS . This is usually handled automatically by xsubpp .

    1. dXSARGS;
  • dXSI32

    Sets up the ix variable for an XSUB which has aliases. This is usually handled automatically by xsubpp .

    1. dXSI32;
  • items

    Variable which is setup by xsubpp to indicate the number of items on the stack. See Variable-length Parameter Lists in perlxs.

    1. I32 items
  • ix

    Variable which is setup by xsubpp to indicate which of an XSUB's aliases was used to invoke it. See The ALIAS: Keyword in perlxs.

    1. I32 ix
  • newXSproto

    Used by xsubpp to hook up XSUBs as Perl subs. Adds Perl prototypes to the subs.

  • RETVAL

    Variable which is setup by xsubpp to hold the return value for an XSUB. This is always the proper type for the XSUB. See The RETVAL Variable in perlxs.

    1. (whatever) RETVAL
  • ST

    Used to access elements on the XSUB's stack.

    1. SV* ST(int ix)
  • THIS

    Variable which is setup by xsubpp to designate the object in a C++ XSUB. This is always the proper type for the C++ object. See CLASS and Using XS With C++ in perlxs.

    1. (whatever) THIS
  • UNDERBAR

    The SV* corresponding to the $_ variable. Works even if there is a lexical $_ in scope.

  • XS

    Macro to declare an XSUB and its C parameter list. This is handled by xsubpp .

  • XS_VERSION

    The version identifier for an XS module. This is usually handled automatically by ExtUtils::MakeMaker . See XS_VERSION_BOOTCHECK .

  • XS_VERSION_BOOTCHECK

    Macro to verify that a PM module's $VERSION variable matches the XS module's XS_VERSION variable. This is usually handled automatically by xsubpp . See The VERSIONCHECK: Keyword in perlxs.

    1. XS_VERSION_BOOTCHECK;

Warning and Dieing

  • croak

    This is the XSUB-writer's interface to Perl's die function. Normally call this function the same way you call the C printf function. Calling croak returns control directly to Perl, sidestepping the normal C order of execution. See warn.

    If you want to throw an exception object, assign the object to $@ and then pass NULL to croak():

    1. errsv = get_sv("@", GV_ADD);
    2. sv_setsv(errsv, exception_object);
    3. croak(NULL);
    4. void croak(const char* pat, ...)
  • warn

    This is the XSUB-writer's interface to Perl's warn function. Call this function the same way you call the C printf function. See croak .

    1. void warn(const char* pat, ...)

Undocumented functions

These functions are currently undocumented:

  • GetVars
  • Gv_AMupdate
  • PerlIO_clearerr
  • PerlIO_close
  • PerlIO_context_layers
  • PerlIO_eof
  • PerlIO_error
  • PerlIO_fileno
  • PerlIO_fill
  • PerlIO_flush
  • PerlIO_get_base
  • PerlIO_get_bufsiz
  • PerlIO_get_cnt
  • PerlIO_get_ptr
  • PerlIO_read
  • PerlIO_seek
  • PerlIO_set_cnt
  • PerlIO_set_ptrcnt
  • PerlIO_setlinebuf
  • PerlIO_stderr
  • PerlIO_stdin
  • PerlIO_stdout
  • PerlIO_tell
  • PerlIO_unread
  • PerlIO_write
  • Slab_Alloc
  • Slab_Free
  • amagic_call
  • any_dup
  • apply_attrs_string
  • atfork_lock
  • atfork_unlock
  • av_arylen_p
  • av_iter_p
  • block_gimme
  • call_atexit
  • call_list
  • calloc
  • cast_i32
  • cast_iv
  • cast_ulong
  • cast_uv
  • ck_warner
  • ck_warner_d
  • ckwarn
  • ckwarn_d
  • croak_nocontext
  • csighandler
  • custom_op_desc
  • custom_op_name
  • cx_dump
  • cx_dup
  • cxinc
  • deb
  • deb_nocontext
  • debop
  • debprofdump
  • debstack
  • debstackptrs
  • delimcpy
  • despatch_signals
  • die
  • die_nocontext
  • dirp_dup
  • do_aspawn
  • do_binmode
  • do_close
  • do_gv_dump
  • do_gvgv_dump
  • do_hv_dump
  • do_join
  • do_magic_dump
  • do_op_dump
  • do_open
  • do_open9
  • do_openn
  • do_pmop_dump
  • do_spawn
  • do_spawn_nowait
  • do_sprintf
  • do_sv_dump
  • doing_taint
  • doref
  • dounwind
  • dowantarray
  • dump_all
  • dump_eval
  • dump_fds
  • dump_form
  • dump_indent
  • dump_mstats
  • dump_packsubs
  • dump_sub
  • dump_vindent
  • fetch_cop_label
  • filter_add
  • filter_del
  • filter_read
  • find_rundefsvoffset
  • form_nocontext
  • fp_dup
  • fprintf_nocontext
  • free_global_struct
  • free_tmps
  • get_context
  • get_mstats
  • get_op_descs
  • get_op_names
  • get_ppaddr
  • get_vtbl
  • gp_dup
  • gp_free
  • gp_ref
  • gv_AVadd
  • gv_HVadd
  • gv_IOadd
  • gv_SVadd
  • gv_add_by_type
  • gv_autoload4
  • gv_check
  • gv_dump
  • gv_efullname
  • gv_efullname3
  • gv_efullname4
  • gv_fetchfile
  • gv_fetchfile_flags
  • gv_fetchmethod_flags
  • gv_fetchpv
  • gv_fetchpvn_flags
  • gv_fetchsv
  • gv_fullname
  • gv_fullname3
  • gv_fullname4
  • gv_handler
  • gv_init
  • gv_name_set
  • he_dup
  • hek_dup
  • hv_common
  • hv_common_key_len
  • hv_delayfree_ent
  • hv_eiter_p
  • hv_eiter_set
  • hv_free_ent
  • hv_ksplit
  • hv_name_set
  • hv_placeholders_get
  • hv_placeholders_p
  • hv_placeholders_set
  • hv_riter_p
  • hv_riter_set
  • hv_store_flags
  • ibcmp
  • ibcmp_locale
  • init_global_struct
  • init_i18nl10n
  • init_i18nl14n
  • init_stacks
  • init_tm
  • instr
  • is_lvalue_sub
  • is_uni_alnum
  • is_uni_alnum_lc
  • is_uni_alpha
  • is_uni_alpha_lc
  • is_uni_ascii
  • is_uni_ascii_lc
  • is_uni_cntrl
  • is_uni_cntrl_lc
  • is_uni_digit
  • is_uni_digit_lc
  • is_uni_graph
  • is_uni_graph_lc
  • is_uni_idfirst
  • is_uni_idfirst_lc
  • is_uni_lower
  • is_uni_lower_lc
  • is_uni_print
  • is_uni_print_lc
  • is_uni_punct
  • is_uni_punct_lc
  • is_uni_space
  • is_uni_space_lc
  • is_uni_upper
  • is_uni_upper_lc
  • is_uni_xdigit
  • is_uni_xdigit_lc
  • is_utf8_alnum
  • is_utf8_alpha
  • is_utf8_ascii
  • is_utf8_cntrl
  • is_utf8_digit
  • is_utf8_graph
  • is_utf8_idcont
  • is_utf8_idfirst
  • is_utf8_lower
  • is_utf8_mark
  • is_utf8_perl_space
  • is_utf8_perl_word
  • is_utf8_posix_digit
  • is_utf8_print
  • is_utf8_punct
  • is_utf8_space
  • is_utf8_upper
  • is_utf8_xdigit
  • leave_scope
  • load_module_nocontext
  • magic_dump
  • malloc
  • markstack_grow
  • mess
  • mess_nocontext
  • mfree
  • mg_dup
  • mg_size
  • mini_mktime
  • moreswitches
  • mro_get_from_name
  • mro_get_private_data
  • mro_register
  • mro_set_mro
  • mro_set_private_data
  • my_atof
  • my_atof2
  • my_bcopy
  • my_bzero
  • my_chsize
  • my_cxt_index
  • my_cxt_init
  • my_dirfd
  • my_exit
  • my_failure_exit
  • my_fflush_all
  • my_fork
  • my_htonl
  • my_lstat
  • my_memcmp
  • my_memset
  • my_ntohl
  • my_pclose
  • my_popen
  • my_popen_list
  • my_setenv
  • my_socketpair
  • my_stat
  • my_strftime
  • my_strlcat
  • my_strlcpy
  • my_swap
  • newANONATTRSUB
  • newANONHASH
  • newANONLIST
  • newANONSUB
  • newASSIGNOP
  • newATTRSUB
  • newAVREF
  • newBINOP
  • newCONDOP
  • newCVREF
  • newFORM
  • newFOROP
  • newGIVENOP
  • newGVOP
  • newGVREF
  • newGVgen
  • newHVREF
  • newHVhv
  • newIO
  • newLISTOP
  • newLOGOP
  • newLOOPEX
  • newLOOPOP
  • newMYSUB
  • newNULLLIST
  • newOP
  • newPADOP
  • newPMOP
  • newPROG
  • newPVOP
  • newRANGE
  • newRV
  • newSLICEOP
  • newSTATEOP
  • newSUB
  • newSVOP
  • newSVREF
  • newSVpvf_nocontext
  • newUNOP
  • newWHENOP
  • newWHILEOP
  • newXS_flags
  • new_collate
  • new_ctype
  • new_numeric
  • new_stackinfo
  • ninstr
  • op_dump
  • op_free
  • op_null
  • op_refcnt_lock
  • op_refcnt_unlock
  • parser_dup
  • perl_alloc_using
  • perl_clone_using
  • pmop_dump
  • pop_scope
  • pregcomp
  • pregexec
  • pregfree
  • pregfree2
  • printf_nocontext
  • ptr_table_clear
  • ptr_table_fetch
  • ptr_table_free
  • ptr_table_new
  • ptr_table_split
  • ptr_table_store
  • push_scope
  • re_compile
  • re_dup_guts
  • re_intuit_start
  • re_intuit_string
  • realloc
  • reentrant_free
  • reentrant_init
  • reentrant_retry
  • reentrant_size
  • ref
  • reg_named_buff_all
  • reg_named_buff_exists
  • reg_named_buff_fetch
  • reg_named_buff_firstkey
  • reg_named_buff_nextkey
  • reg_named_buff_scalar
  • regclass_swash
  • regdump
  • regdupe_internal
  • regexec_flags
  • regfree_internal
  • reginitcolors
  • regnext
  • repeatcpy
  • rninstr
  • rsignal
  • rsignal_state
  • runops_debug
  • runops_standard
  • rvpv_dup
  • safesyscalloc
  • safesysfree
  • safesysmalloc
  • safesysrealloc
  • save_I16
  • save_I32
  • save_I8
  • save_adelete
  • save_aelem
  • save_aelem_flags
  • save_alloc
  • save_aptr
  • save_ary
  • save_bool
  • save_clearsv
  • save_delete
  • save_destructor
  • save_destructor_x
  • save_freepv
  • save_freesv
  • save_generic_pvref
  • save_generic_svref
  • save_gp
  • save_hash
  • save_hdelete
  • save_helem
  • save_helem_flags
  • save_hptr
  • save_int
  • save_item
  • save_iv
  • save_list
  • save_long
  • save_mortalizesv
  • save_nogv
  • save_padsv_and_mortalize
  • save_pptr
  • save_pushptr
  • save_re_context
  • save_scalar
  • save_set_svflags
  • save_shared_pvref
  • save_sptr
  • save_svref
  • save_vptr
  • savestack_grow
  • savestack_grow_cnt
  • scan_num
  • scan_vstring
  • screaminstr
  • seed
  • set_context
  • set_numeric_local
  • set_numeric_radix
  • set_numeric_standard
  • share_hek
  • si_dup
  • ss_dup
  • stack_grow
  • start_subparse
  • stashpv_hvname_match
  • str_to_version
  • sv_2iv
  • sv_2pv
  • sv_2uv
  • sv_catpvf_mg_nocontext
  • sv_catpvf_nocontext
  • sv_compile_2op
  • sv_dump
  • sv_dup
  • sv_peek
  • sv_pvn_nomg
  • sv_setpvf_mg_nocontext
  • sv_setpvf_nocontext
  • sv_utf8_upgrade_flags_grow
  • swash_fetch
  • swash_init
  • sys_init
  • sys_init3
  • sys_intern_clear
  • sys_intern_dup
  • sys_intern_init
  • sys_term
  • taint_env
  • taint_proper
  • tmps_grow
  • to_uni_fold
  • to_uni_lower
  • to_uni_lower_lc
  • to_uni_title
  • to_uni_title_lc
  • to_uni_upper
  • to_uni_upper_lc
  • unlnk
  • unsharepvn
  • utf16_to_utf8
  • utf16_to_utf8_reversed
  • uvchr_to_utf8_flags
  • uvuni_to_utf8
  • vcroak
  • vdeb
  • vform
  • vload_module
  • vmess
  • vnewSVpvf
  • vwarn
  • vwarner
  • warn_nocontext
  • warner
  • warner_nocontext
  • whichsig

AUTHORS

Until May 1997, this document was maintained by Jeff Okamoto <okamoto@corp.hp.com>. It is now maintained as part of Perl itself.

With lots of help and suggestions from Dean Roehrich, Malcolm Beattie, Andreas Koenig, Paul Hudson, Ilya Zakharevich, Paul Marquess, Neil Bowers, Matthew Green, Tim Bunce, Spider Boardman, Ulrich Pfeifer, Stephen McCamant, and Gurusamy Sarathy.

API Listing originally by Dean Roehrich <roehrich@cray.com>.

Updated to be autogenerated from comments in the source by Benjamin Stuhl.

SEE ALSO

perlguts, perlxs, perlxstut, perlintern