• NAME
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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.

The listing is alphabetical, case insensitive.

AvFILL

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

        int     AvFILL(AV* av)

av_clear

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

        void    av_clear(AV* ar)

av_extend

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

        void    av_extend(AV* ar, 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 the perlguts manpage for more information on how to use this function on tied arrays.

        SV**    av_fetch(AV* ar, I32 key, I32 lval)

av_len

Returns the highest index in the array. Returns -1 if the array is empty.

        I32     av_len(AV* ar)

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.

        AV*     av_make(I32 size, SV** svp)

av_pop

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

        SV*     av_pop(AV* ar)

av_push

Pushes an SV onto the end of the array. The array will grow automatically to accommodate the addition.

        void    av_push(AV* ar, SV* val)

av_shift

Shifts an SV off the beginning of the array.

        SV*     av_shift(AV* ar)

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 the perlguts manpage for more information on how to use this function on tied arrays.

        SV**    av_store(AV* ar, I32 key, SV* val)

av_undef

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

        void    av_undef(AV* ar)

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.

        void    av_unshift(AV* ar, I32 num)

call_argv

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

NOTE: the perl_ form of this function is deprecated.

        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 the perlcall manpage.

NOTE: the perl_ form of this function is deprecated.

        I32     call_method(const char* methname, I32 flags)

call_pv

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

NOTE: the perl_ form of this function is deprecated.

        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 the perlcall manpage.

NOTE: the perl_ form of this function is deprecated.

        I32     call_sv(SV* sv, I32 flags)

CLASS

Variable which is setup by xsubpp to indicate the class name for a C++ XS constructor. This is always a char*. See THIS.

        char*   CLASS

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.

        void    Copy(void* src, void* dest, int nitems, type)

croak

This is the XSUB-writer's interface to Perl's die function. Normally use this function the same way you use the C printf function. See warn.

If you want to throw an exception object, assign the object to $@ and then pass Nullch to croak():

   errsv = get_sv("@", TRUE);
   sv_setsv(errsv, exception_object);
   croak(Nullch);

        void    croak(const char* pat, ...)

CvSTASH

Returns the stash of the CV.

        HV*     CvSTASH(CV* cv)

dMARK

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

                dMARK;

dORIGMARK

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

                dORIGMARK;

dSP

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

                dSP;

dXSARGS

Sets up stack and mark pointers for an XSUB, calling dSP and dMARK. This is usually handled automatically by xsubpp. Declares the items variable to indicate the number of items on the stack.

                dXSARGS;

dXSI32

Sets up the ix variable for an XSUB which has aliases. This is usually handled automatically by xsubpp.

                dXSI32;

ENTER

Opening bracket on a callback. See LEAVE and the perlcall manpage.

                ENTER;

eval_pv

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

NOTE: the perl_ form of this function is deprecated.

        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.

        I32     eval_sv(SV* sv, I32 flags)

EXTEND

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

        void    EXTEND(SP, int nitems)

fbm_compile

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

        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 Nullch 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.

        char*   fbm_instr(unsigned char* big, unsigned char* bigend, SV* littlesv, U32 flags)

FREETMPS

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

                FREETMPS;

get_av

Returns the AV of the specified Perl array. If create is set and the Perl variable does not exist then it will be created. If create is not set and the variable does not exist then NULL is returned.

NOTE: the perl_ form of this function is deprecated.

        AV*     get_av(const char* name, I32 create)

get_cv

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

NOTE: the perl_ form of this function is deprecated.

        CV*     get_cv(const char* name, I32 create)

get_hv

Returns the HV of the specified Perl hash. If create is set and the Perl variable does not exist then it will be created. If create is not set and the variable does not exist then NULL is returned.

NOTE: the perl_ form of this function is deprecated.

        HV*     get_hv(const char* name, I32 create)

get_sv

Returns the SV of the specified Perl scalar. If create is set and the Perl variable does not exist then it will be created. If create is not set and the variable does not exist then NULL is returned.

NOTE: the perl_ form of this function is deprecated.

        SV*     get_sv(const char* name, I32 create)

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.

        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 array context, respectively.

        U32     GIMME_V

GvSV

Return the SV from the GV.

        SV*     GvSV(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. Similarly for all the searched stashes.

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.

        GV*     gv_fetchmeth(HV* stash, const char* name, STRLEN len, I32 level)

gv_fetchmethod

See gv_fetchmethod_autoload.

        GV*     gv_fetchmethod(HV* stash, const char* name)

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.

        GV*     gv_fetchmethod_autoload(HV* stash, const char* name, I32 autoload)

gv_stashpv

Returns a pointer to the stash for a specified package. name should be a valid UTF-8 string. If create is set then the package will be created if it does not already exist. If create is not set and the package does not exist then NULL is returned.

        HV*     gv_stashpv(const char* name, I32 create)

gv_stashsv

Returns a pointer to the stash for a specified package, which must be a valid UTF-8 string. See gv_stashpv.

        HV*     gv_stashsv(SV* sv, I32 create)

G_ARRAY

Used to indicate array context. See GIMME_V, GIMME and the perlcall manpage.

G_DISCARD

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

G_EVAL

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

G_NOARGS

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

G_SCALAR

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

G_VOID

Used to indicate void context. See GIMME_V and the perlcall manpage.

HEf_SVKEY

This flag, used in the length slot of hash entries and magic structures, specifies the structure contains a 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.

        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.

        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.

        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.

        char*   HePV(HE* he, STRLEN len)

HeSVKEY

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

        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.

        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*.

        SV*     HeSVKEY_set(HE* he, SV* sv)

HeVAL

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

        SV*     HeVAL(HE* he)

HvNAME

Returns the package name of a stash. See SvSTASH, CvSTASH.

        char*   HvNAME(HV* stash)

hv_clear

Clears a hash, making it empty.

        void    hv_clear(HV* tb)

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.

        SV*     hv_delete(HV* tb, const char* key, U32 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.

        SV*     hv_delete_ent(HV* tb, SV* key, I32 flags, U32 hash)

hv_exists

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

        bool    hv_exists(HV* tb, const char* key, U32 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.

        bool    hv_exists_ent(HV* tb, SV* key, 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 a SV*.

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

        SV**    hv_fetch(HV* tb, const char* key, U32 klen, 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 the perlguts manpage for more information on how to use this function on tied hashes.

        HE*     hv_fetch_ent(HV* tb, SV* key, 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).

        I32     hv_iterinit(HV* tb)

hv_iterkey

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

        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.

        SV*     hv_iterkeysv(HE* entry)

hv_iternext

Returns entries from a hash iterator. See hv_iterinit.

        HE*     hv_iternext(HV* tb)

hv_iternextsv

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

        SV*     hv_iternextsv(HV* hv, char** key, I32* retlen)

hv_iterval

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

        SV*     hv_iterval(HV* tb, HE* entry)

hv_magic

Adds magic to a hash. See sv_magic.

        void    hv_magic(HV* hv, GV* gv, int how)

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.

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

        SV**    hv_store(HV* tb, const char* key, U32 klen, SV* val, U32 hash)

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.

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

        HE*     hv_store_ent(HV* tb, SV* key, SV* val, U32 hash)

hv_undef

Undefines the hash.

        void    hv_undef(HV* tb)

isALNUM

Returns a boolean indicating whether the C char is an ascii alphanumeric character or digit.

        bool    isALNUM(char ch)

isALPHA

Returns a boolean indicating whether the C char is an ascii alphabetic character.

        bool    isALPHA(char ch)

isDIGIT

Returns a boolean indicating whether the C char is an ascii digit.

        bool    isDIGIT(char ch)

isLOWER

Returns a boolean indicating whether the C char is a lowercase character.

        bool    isLOWER(char ch)

isSPACE

Returns a boolean indicating whether the C char is whitespace.

        bool    isSPACE(char ch)

isUPPER

Returns a boolean indicating whether the C char is an uppercase character.

        bool    isUPPER(char ch)

items

Variable which is setup by xsubpp to indicate the number of items on the stack. See Variable-length Parameter Lists in the perlxs manpage.

        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 the perlxs manpage.

        I32     ix

LEAVE

Closing bracket on a callback. See ENTER and the perlcall manpage.

                LEAVE;

looks_like_number

Test if an the content of an SV looks like a number (or is a number).

        I32     looks_like_number(SV* sv)

MARK

Stack marker variable for the XSUB. See dMARK.

mg_clear

Clear something magical that the SV represents. See sv_magic.

        int     mg_clear(SV* sv)

mg_copy

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

        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.

        MAGIC*  mg_find(SV* sv, int type)

mg_free

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

        int     mg_free(SV* sv)

mg_get

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

        int     mg_get(SV* sv)

mg_length

Report on the SV's length. See sv_magic.

        U32     mg_length(SV* sv)

mg_magical

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

        void    mg_magical(SV* sv)

mg_set

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

        int     mg_set(SV* sv)

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.

        void    Move(void* src, void* dest, int nitems, type)

New

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

        void    New(int id, void* ptr, int nitems, type)

newAV

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

        AV*     newAV()

Newc

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

        void    Newc(int id, void* ptr, int nitems, type, cast)

newCONSTSUB

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

        void    newCONSTSUB(HV* stash, char* name, SV* sv)

newHV

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

        HV*     newHV()

newRV_inc

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

        SV*     newRV_inc(SV* sv)

newRV_noinc

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

        SV*     newRV_noinc(SV *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 tailing 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. id is an integer id between 0 and 1299 (used to identify leaks).

        SV*     NEWSV(int id, STRLEN len)

newSViv

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

        SV*     newSViv(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.

        SV*     newSVnv(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.

        SV*     newSVpv(const char* s, STRLEN len)

newSVpvf

Creates a new SV an initialize it with the string formatted like sprintf.

        SV*     newSVpvf(const char* 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.

        SV*     newSVpvn(const char* s, STRLEN len)

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.

        SV*     newSVrv(SV* rv, const char* classname)

newSVsv

Creates a new SV which is an exact duplicate of the original SV.

        SV*     newSVsv(SV* old)

newSVuv

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

        SV*     newSVuv(UV u)

newXS

Used by xsubpp to hook up XSUBs as Perl subs.

newXSproto

Used by xsubpp to hook up XSUBs as Perl subs. Adds Perl prototypes to the subs.

Newz

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

        void    Newz(int id, void* ptr, int nitems, type)

Nullav

Null AV pointer.

Nullch

Null character pointer.

Nullcv

Null CV pointer.

Nullhv

Null HV pointer.

Nullsv

Null SV pointer.

ORIGMARK

The original stack mark for the XSUB. See dORIGMARK.

perl_alloc

Allocates a new Perl interpreter. See the perlembed manpage.

        PerlInterpreter*        perl_alloc()

perl_construct

Initializes a new Perl interpreter. See the perlembed manpage.

        void    perl_construct(PerlInterpreter* interp)

perl_destruct

Shuts down a Perl interpreter. See the perlembed manpage.

        void    perl_destruct(PerlInterpreter* interp)

perl_free

Releases a Perl interpreter. See the perlembed manpage.

        void    perl_free(PerlInterpreter* interp)

perl_parse

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

        int     perl_parse(PerlInterpreter* interp, XSINIT_t xsinit, int argc, char** argv, char** env)

perl_run

Tells a Perl interpreter to run. See the perlembed manpage.

        int     perl_run(PerlInterpreter* interp)

PL_DBsingle

When Perl is run in debugging mode, with the -d switch, this SV is a boolean which indicates whether subs are being single-stepped. Single-stepping is automatically turned on after every step. This is the C variable which corresponds to Perl's $DB::single variable. See PL_DBsub.

        SV *    PL_DBsingle

PL_DBsub

When Perl is run in debugging mode, with the -d switch, this GV contains the SV which holds the name of the sub being debugged. This is the C variable which corresponds to Perl's $DB::sub variable. See PL_DBsingle.

        GV *    PL_DBsub

PL_DBtrace

Trace variable used when Perl is run in debugging mode, with the -d switch. This is the C variable which corresponds to Perl's $DB::trace variable. See PL_DBsingle.

        SV *    PL_DBtrace

PL_dowarn

The C variable which corresponds to Perl's $^W warning variable.

        bool    PL_dowarn

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.

        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.

        STRLEN  PL_na

PL_sv_no

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

        SV      PL_sv_no

PL_sv_undef

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

        SV      PL_sv_undef

PL_sv_yes

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

        SV      PL_sv_yes

POPi

Pops an integer off the stack.

        IV      POPi

POPl

Pops a long off the stack.

        long    POPl

POPn

Pops a double off the stack.

        NV      POPn

POPp

Pops a string off the stack.

        char*   POPp

POPs

Pops an SV off the stack.

        SV*     POPs

PUSHi

Push an integer onto the stack. The stack must have room for this element. Handles 'set' magic. See XPUSHi.

        void    PUSHi(IV iv)

PUSHMARK

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

                PUSHMARK;

PUSHn

Push a double onto the stack. The stack must have room for this element. Handles 'set' magic. See XPUSHn.

        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. See XPUSHp.

        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. See XPUSHs.

        void    PUSHs(SV* sv)

PUSHu

Push an unsigned integer onto the stack. The stack must have room for this element. See XPUSHu.

        void    PUSHu(UV uv)

PUTBACK

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

                PUTBACK;

Renew

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

        void    Renew(void* ptr, int nitems, type)

Renewc

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

        void    Renewc(void* ptr, int nitems, type, cast)

require_pv

Tells Perl to require a module.

NOTE: the perl_ form of this function is deprecated.

        void    require_pv(const char* pv)

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 the perlxs manpage.

        (whatever)      RETVAL

Safefree

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

        void    Safefree(void* src, void* dest, int nitems, type)

savepv

Copy a string to a safe spot. This does not use an SV.

        char*   savepv(const char* sv)

savepvn

Copy a string to a safe spot. The len indicates number of bytes to copy. This does not use an SV.

        char*   savepvn(const char* sv, I32 len)

SAVETMPS

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

                SAVETMPS;

SP

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

SPAGAIN

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

                SPAGAIN;

ST

Used to access elements on the XSUB's stack.

        SV*     ST(int ix)

strEQ

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

        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.

        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.

        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.

        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.

        bool    strLT(char* s1, char* s2)

strNE

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

        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).

        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).

        bool    strnNE(char* s1, char* s2, STRLEN len)

StructCopy

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

        void    StructCopy(type src, type dest, type)

SvCUR

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

        STRLEN  SvCUR(SV* sv)

SvCUR_set

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

        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)).

        char*   SvEND(SV* sv)

SvGETMAGIC

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

        void    SvGETMAGIC(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.

        void    SvGROW(SV* sv, STRLEN len)

SvIOK

Returns a boolean indicating whether the SV contains an integer.

        bool    SvIOK(SV* sv)

SvIOKp

Returns a boolean indicating whether the SV contains an integer. Checks the private setting. Use SvIOK.

        bool    SvIOKp(SV* sv)

SvIOK_off

Unsets the IV status of an SV.

        void    SvIOK_off(SV* sv)

SvIOK_on

Tells an SV that it is an integer.

        void    SvIOK_on(SV* sv)

SvIOK_only

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

        void    SvIOK_only(SV* sv)

SvIV

Coerces the given SV to an integer and returns it.

        IV      SvIV(SV* sv)

SvIVX

Returns the integer which is stored in the SV, assuming SvIOK is true.

        IV      SvIVX(SV* sv)

SvLEN

Returns the size of the string buffer in the SV. See SvCUR.

        STRLEN  SvLEN(SV* sv)

SvNIOK

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

        bool    SvNIOK(SV* sv)

SvNIOKp

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

        bool    SvNIOKp(SV* sv)

SvNIOK_off

Unsets the NV/IV status of an SV.

        void    SvNIOK_off(SV* sv)

SvNOK

Returns a boolean indicating whether the SV contains a double.

        bool    SvNOK(SV* sv)

SvNOKp

Returns a boolean indicating whether the SV contains a double. Checks the private setting. Use SvNOK.

        bool    SvNOKp(SV* sv)

SvNOK_off

Unsets the NV status of an SV.

        void    SvNOK_off(SV* sv)

SvNOK_on

Tells an SV that it is a double.

        void    SvNOK_on(SV* sv)

SvNOK_only

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

        void    SvNOK_only(SV* sv)

SvNV

Coerce the given SV to a double and return it.

        NV      SvNV(SV* sv)

SvNVX

Returns the double which is stored in the SV, assuming SvNOK is true.

        NV      SvNVX(SV* sv)

SvOK

Returns a boolean indicating whether the value is an SV.

        bool    SvOK(SV* sv)

SvOOK

Returns a boolean indicating whether the SvIVX is a valid offset value for the SvPVX. 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 really (SvPVX - SvIVX).

        bool    SvOOK(SV* sv)

SvPOK

Returns a boolean indicating whether the SV contains a character string.

        bool    SvPOK(SV* sv)

SvPOKp

Returns a boolean indicating whether the SV contains a character string. Checks the private setting. Use SvPOK.

        bool    SvPOKp(SV* sv)

SvPOK_off

Unsets the PV status of an SV.

        void    SvPOK_off(SV* sv)

SvPOK_on

Tells an SV that it is a string.

        void    SvPOK_on(SV* sv)

SvPOK_only

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

        void    SvPOK_only(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. Handles 'get' magic.

        char*   SvPV(SV* sv, STRLEN len)

SvPVX

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

        char*   SvPVX(SV* sv)

SvPV_force

Like <SvPV> but will force the SV into becoming a string (SvPOK). You want force if you are going to update the SvPVX directly.

        char*   SvPV_force(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. Handles 'get' magic.

        char*   SvPV_nolen(SV* sv)

SvREFCNT

Returns the value of the object's reference count.

        U32     SvREFCNT(SV* sv)

SvREFCNT_dec

Decrements the reference count of the given SV.

        void    SvREFCNT_dec(SV* sv)

SvREFCNT_inc

Increments the reference count of the given SV.

        SV*     SvREFCNT_inc(SV* sv)

SvROK

Tests if the SV is an RV.

        bool    SvROK(SV* sv)

SvROK_off

Unsets the RV status of an SV.

        void    SvROK_off(SV* sv)

SvROK_on

Tells an SV that it is an RV.

        void    SvROK_on(SV* sv)

SvRV

Dereferences an RV to return the SV.

        SV*     SvRV(SV* sv)

SvSETMAGIC

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

        void    SvSETMAGIC(SV* sv)

SvSetSV

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

        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.

        void    SvSetSV_nosteal(SV* dsv, SV* ssv)

SvSTASH

Returns the stash of the SV.

        HV*     SvSTASH(SV* sv)

SvTAINT

Taints an SV if tainting is enabled

        void    SvTAINT(SV* sv)

SvTAINTED

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

        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