API LISTING

This is a listing of functions, macros, flags, and variables that may be useful to extension writers or that may be found while reading other 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 will be removed in a future release.

It is strongly recommended that all Perl API functions that don't begin with perl be referenced with an explicit Perl_ prefix.

The sort order of the listing is case insensitive, with any occurrences of '_' ignored for the the purpose of sorting.

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

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

AvFILL

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

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 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)

CLASS

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

Copy

The XSUB-writer's interface to the C memcpy function. The s is the source, d is the destination, n is the number of items, and t is the type. May fail on overlapping copies. See also Move.

void Copy( s, d, n, t )

croak

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

CvSTASH

Returns the stash of the CV.

HV* CvSTASH( SV* sv )

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.

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. The sub name can be found by

SvPV( GvSV( PL_DBsub ), PL_na )

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.

dMARK

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

dORIGMARK

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

PL_dowarn

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

dSP

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

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.

dXSI32

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

do_binmode

Switches filehandle to binmode. iotype is what IoTYPE(io) would contain.

do_binmode(fp, iotype, TRUE);

ENTER

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

ENTER;

EXTEND

Used to extend the argument stack for an XSUB's return values.

EXTEND( sp, int x )

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(char *str, char *strend, SV *sv, U32 flags)

FREETMPS

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

FREETMPS;

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.

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.

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.

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.

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 perl_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, char* name, STRLEN len, I32 level)

gv_fetchmethod
gv_fetchmethod_autoload

Returns the glob which contains the subroutine to call to invoke the method on the stash. In fact in the presense 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 perl_call_sv apply equally to these functions.

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

G_VOID

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

gv_stashpv

Returns a pointer to the stash for a specified package. 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 (char* name, I32 create)

gv_stashsv

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

HV* gv_stashsv (SV* sv, I32 create)

GvSV

Return the SV from the GV.

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.

char* 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.

int 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. 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.

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.

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*.

HeSVKEY_set(HE* he, SV* sv)

HeVAL

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

HeVAL(HE* he)

hv_clear

Clears a hash, making it empty.

void hv_clear (HV* tb)

hv_delayfree_ent

Releases a hash entry, such as while iterating though the hash, but delays actual freeing of key and value until the end of the current statement (or thereabouts) with sv_2mortal. See hv_iternext and hv_free_ent.

void hv_delayfree_ent (HV* hv, HE* entry)

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, 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, 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 for more information on how to use this function on tied hashes.

SV** hv_fetch (HV* tb, 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 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_free_ent

Releases a hash entry, such as while iterating though the hash. See hv_iternext and hv_delayfree_ent.

void hv_free_ent (HV* hv, HE* entry)

hv_iterinit

Prepares a starting point to traverse a hash table.

I32 hv_iterinit (HV* tb)

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).

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)

HvNAME

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

char* HvNAME (HV* stash)

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 for more information on how to use this function on tied hashes.

SV** hv_store (HV* tb, 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 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.

int isALNUM (char c)

isALPHA

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

int isALPHA (char c)

isDIGIT

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

int isDIGIT (char c)

isLOWER

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

int isLOWER (char c)

isSPACE

Returns a boolean indicating whether the C char is whitespace.

int isSPACE (char c)

isUPPER

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

int isUPPER (char c)

items

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

ix

Variable which is setup by xsubpp to indicate which of an XSUB's aliases was used to invoke it. See The ALIAS: Keyword.

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).

int looks_like_number(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 *, char *, STRLEN)

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_len

Report on the SV's length. See sv_magic.

U32 mg_len (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 s is the source, d is the destination, n is the number of items, and t is the type. Can do overlapping moves. See also Copy.

void Move( s, d, n, t )

PL_na

A variable which may be used with SvPV to tell Perl to calculate the string length.

New

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

void* New( x, void *ptr, int size, type )

newAV

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

AV* newAV (void)

Newc

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

void* Newc( x, void *ptr, int size, 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 (void)

newRV_inc

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

SV* newRV_inc (SV* ref)

For historical reasons, ``newRV'' is a synonym for ``newRV_inc''.

newRV_noinc

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

SV* newRV_noinc (SV* ref)

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 double into it. The reference count for the SV is set to 1.

SV* newSVnv (NV i)

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 then Perl will compute the length.

SV* newSVpv (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. If len is zero then Perl will create a zero length string.

SV* newSVpvn (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, char* classname)

newSVsv

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

SV* newSVsv (SV* old)

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( x, void *ptr, int size, 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.

perl_call_argv

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

I32 perl_call_argv (char* subname, I32 flags, char** argv)

perl_call_method

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

I32 perl_call_method (char* methname, I32 flags)

perl_call_pv

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

I32 perl_call_pv (char* subname, I32 flags)

perl_call_sv

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

I32 perl_call_sv (SV* sv, I32 flags)

perl_construct

Initializes a new Perl interpreter. See the perlembed manpage.

perl_destruct

Shuts down a Perl interpreter. See the perlembed manpage.

perl_eval_sv

Tells Perl to eval the string in the SV.

I32 perl_eval_sv (SV* sv, I32 flags)

perl_eval_pv

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

SV* perl_eval_pv (char* p, I32 croak_on_error)

perl_free

Releases a Perl interpreter. See the perlembed manpage.

perl_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.

AV* perl_get_av (char* name, I32 create)

perl_get_cv

Returns the CV of the specified Perl sub. 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.

CV* perl_get_cv (char* name, I32 create)

perl_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.

HV* perl_get_hv (char* name, I32 create)

perl_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.

SV* perl_get_sv (char* name, I32 create)

perl_parse

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

perl_require_pv

Tells Perl to require a module.

void perl_require_pv (char* pv)

perl_run

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

POPi

Pops an integer off the stack.

int POPi()

POPl

Pops a long off the stack.

long POPl()

POPp

Pops a string off the stack.

char* POPp()

POPn

Pops a double off the stack.

double POPn()

POPs

Pops an SV off the stack.

SV* POPs()

PUSHMARK

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

PUSHMARK(p)

PUSHi

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

void PUSHi(int d)

PUSHn

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

void PUSHn(double d)

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 *c, int 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)

PUSHu

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

void PUSHu(unsigned int d)

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 size, type )

Renewc

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

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

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.

safefree

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

safemalloc

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

saferealloc

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

savepv

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

char* savepv (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 (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 x)

strEQ

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

int 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.

int 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.

int 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.

int 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.

int strLT( char *s1, char *s2 )

strNE

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

int 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.

int strnEQ( char *s1, char *s2 )

strnNE

Test two strings to see if they are different. The len parameter indicates the number of bytes to compare. Returns true or false.

int strnNE( char *s1, char *s2, int len )

sv_2mortal

Marks an SV as mortal. The SV will be destroyed when the current context ends.

SV* sv_2mortal (SV* 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.

SV* sv_bless (SV* sv, HV* stash)

sv_catpv

Concatenates the string onto the end of the string which is in the SV. Handles 'get' magic, but not 'set' magic. See sv_catpv_mg.

void sv_catpv (SV* sv, char* ptr)

sv_catpv_mg

Like sv_catpv, but also handles 'set' magic.

void sv_catpvn (SV* sv, char* ptr)

sv_catpvn

Concatenates the string onto the end of the string which is in the SV. The len indicates number of bytes to copy. Handles 'get' magic, but not 'set' magic. See sv_catpvn_mg.

void sv_catpvn (SV* sv, char* ptr, STRLEN len)

sv_catpvn_mg

Like sv_catpvn, but also handles 'set' magic.

void sv_catpvn_mg (SV* sv, char* ptr, STRLEN len)

sv_catpvf

Processes its arguments like sprintf and appends the formatted output to an SV. Handles 'get' magic, but not 'set' magic. SvSETMAGIC() must typically be called after calling this function to handle 'set' magic.

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

sv_catpvf_mg

Like sv_catpvf, but also handles 'set' magic.

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

sv_catsv

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

void sv_catsv (SV* dsv, SV* ssv)

sv_catsv_mg

Like sv_catsv, but also handles 'set' magic.

void sv_catsv_mg (SV* dsv, SV* ssv)

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.

void sv_chop(SV* sv, char *ptr)

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.

I32 sv_cmp (SV* sv1, SV* sv2)

SvCUR

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

int SvCUR (SV* sv)

SvCUR_set

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

void SvCUR_set (SV* sv, int val )

sv_dec

Auto-decrement of the value in the SV.

void sv_dec (SV* sv)

sv_derived_from

Returns a boolean indicating whether the SV is a subclass of the specified class.

int sv_derived_from(SV* sv, char* class)

sv_derived_from

Returns a boolean indicating whether the SV is derived from the specified class. This is the function that implements UNIVERSAL::isa. It works for class names as well as for objects.

bool sv_derived_from _((SV* sv, char* name));

SvEND

Returns a pointer to the last character in the string which is in the SV. See SvCUR. Access the character as

char* SvEND(sv)

sv_eq

Returns a boolean indicating whether the strings in the two SVs are identical.

I32 sv_eq (SV* sv1, SV* sv2)

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.

char* SvGROW( SV* sv, int len )

sv_grow

Expands the character buffer in the SV. This will use sv_unref and will upgrade the SV to SVt_PV. Returns a pointer to the character buffer. Use SvGROW.

sv_inc

Auto-increment of the value in the SV.

void sv_inc (SV* sv)

sv_insert

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

void sv_insert(SV *sv, STRLEN offset, STRLEN len,
char *str, STRLEN strlen)

SvIOK

Returns a boolean indicating whether the SV contains an integer.

int SvIOK (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)

SvIOKp

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

int SvIOKp (SV* SV)

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.

int sv_isa (SV* sv, char* 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.

int sv_isobject (SV* sv)

SvIV

Returns the integer which is in the SV.

int SvIV (SV* sv)

SvIVX

Returns the integer which is stored in the SV.

int SvIVX (SV* sv)

SvLEN

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

int SvLEN (SV* sv)

sv_len

Returns the length of the string in the SV. Use SvCUR.

STRLEN sv_len (SV* sv)

sv_magic

Adds magic to an SV.

void sv_magic (SV* sv, SV* obj, int how, char* name, I32 namlen)

sv_mortalcopy

Creates a new SV which is a copy of the original SV. The new SV is marked as mortal.

SV* sv_mortalcopy (SV* oldsv)

sv_newmortal

Creates a new SV which is mortal. The reference count of the SV is set to 1.

SV* sv_newmortal (void)

SvNIOK

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

int SvNIOK (SV* SV)

SvNIOK_off

Unsets the NV/IV status of an SV.

void SvNIOK_off (SV* sv)

SvNIOKp

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

int SvNIOKp (SV* SV)

PL_sv_no

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

SvNOK

Returns a boolean indicating whether the SV contains a double.

int SvNOK (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)

SvNOKp

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

int SvNOKp (SV* SV)

SvNV

Returns the double which is stored in the SV.

double SvNV (SV* sv)

SvNVX

Returns the double which is stored in the SV.

double SvNVX (SV* sv)

SvOK

Returns a boolean indicating whether the value is an SV.

int 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).

int SvOOK(SV* sv)

SvPOK

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

int SvPOK (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)

SvPOKp

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

int SvPOKp (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. If len is PL_na then Perl will handle the length on its own. Handles 'get' magic.

char* SvPV (SV* sv, int len )

SvPV_force

Like 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, int len)

SvPVX

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

char* SvPVX (SV* sv)

SvREFCNT

Returns the value of the object's reference count.

int 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.

void SvREFCNT_inc (SV* sv)

SvROK

Tests if the SV is an RV.

int 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 )

sv_setiv

Copies an integer into the given SV. Does not handle 'set' magic. See sv_setiv_mg.

void sv_setiv (SV* sv, IV num)

sv_setiv_mg

Like sv_setiv, but also handles 'set' magic.

void sv_setiv_mg (SV* sv, IV num)

sv_setnv

Copies a double into the given SV. Does not handle 'set' magic. See sv_setnv_mg.

void sv_setnv (SV* sv, double num)

sv_setnv_mg

Like sv_setnv, but also handles 'set' magic.

void sv_setnv_mg (SV* sv, double num)

sv_setpv

Copies a string into an SV. The string must be null-terminated. Does not handle 'set' magic. See sv_setpv_mg.

void sv_setpv (SV* sv, char* ptr)

sv_setpv_mg

Like sv_setpv, but also handles 'set' magic.

void sv_setpv_mg (SV* sv, char* ptr)

sv_setpviv

Copies an integer into the given SV, also updating its string value. Does not handle 'set' magic. See sv_setpviv_mg.

void sv_setpviv (SV* sv, IV num)

sv_setpviv_mg

Like sv_setpviv, but also handles 'set' magic.

void sv_setpviv_mg (SV* sv, IV num)

sv_setpvn

Copies a string into an SV. The len parameter indicates the number of bytes to be copied. Does not handle 'set' magic. See sv_setpvn_mg.

void sv_setpvn (SV* sv, char* ptr, STRLEN len)

sv_setpvn_mg

Like sv_setpvn, but also handles 'set' magic.

void sv_setpvn_mg (SV* sv, char* ptr, STRLEN len)

sv_setpvf

Processes its arguments like sprintf and sets an SV to the formatted output. Does not handle 'set' magic. See sv_setpvf_mg.

void sv_setpvf (SV* sv, const char* pat, ...)

sv_setpvf_mg

Like sv_setpvf, but also handles 'set' magic.

void sv_setpvf_mg (SV* sv, const char* pat, ...)

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 Nullch to avoid the blessing. The new SV will be returned and will have a reference count of 1.

SV* sv_setref_iv (SV *rv, char *classname, 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 Nullch to avoid the blessing. The new SV will be returned and will have a reference count of 1.

SV* sv_setref_nv (SV *rv, char *classname, double 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 Nullch to avoid the blessing. The new SV will be returned and will have a reference count of 1.

SV* sv_setref_pv (SV *rv, char *classname, void* pv)

Do not use with integral 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.

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 Nullch to avoid the blessing. The new SV will be returned and will have a reference count of 1.

SV* sv_setref_pvn (SV *rv, char *classname, char* pv, I32 n)

Note that sv_setref_pv copies the pointer while this copies the string.

SvSetSV

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

void SvSetSV (SV* dsv, 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)

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. Does not handle 'set' magic. See the macro forms SvSetSV, SvSetSV_nosteal and sv_setsv_mg.

void sv_setsv (SV* dsv, SV* ssv)

sv_setsv_mg

Like sv_setsv, but also handles 'set' magic.

void sv_setsv_mg (SV* dsv, SV* ssv)

sv_setuv

Copies an unsigned integer into the given SV. Does not handle 'set' magic. See sv_setuv_mg.

void sv_setuv (SV* sv, UV num)

sv_setuv_mg

Like sv_setuv, but also handles 'set' magic.

void sv_setuv_mg (SV* sv, UV num)

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.

int 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.

void SvTAINTED_off (SV* sv)

SvTAINTED_on

Marks an SV as tainted.

void SvTAINTED_on (SV* sv)

SVt_IV

Integer 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.

SVt_NV

Double type flag for scalars. See svtype.

SvTRUE

Returns a boolean indicating whether Perl would evaluate the SV as true or false, defined or undefined. Does not handle 'get' magic.

int SvTRUE (SV* sv)

SvTYPE

Returns the type of the SV. See svtype.

svtype SvTYPE (SV* sv)

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.

PL_sv_undef

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

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. See SvROK_off.

void sv_unref (SV* sv)

SvUPGRADE

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

bool SvUPGRADE (SV* sv, svtype mt)

sv_upgrade

Upgrade an SV to a more complex form. Use SvUPGRADE. See svtype.

sv_usepvn

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. This function will realloc the memory pointed to by ptr, so that pointer should not be freed or used by the programmer after giving it to sv_usepvn. Does not handle 'set' magic. See sv_usepvn_mg.

void sv_usepvn (SV* sv, char* ptr, STRLEN len)

sv_usepvn_mg

Like sv_usepvn, but also handles 'set' magic.

void sv_usepvn_mg (SV* sv, char* ptr, STRLEN len)

sv_vcatpvfn(sv, pat, patlen, args, svargs, svmax, used_locale)

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). Indicates if locale information has been used for formatting.

void sv_catpvfn _((SV* sv, const char* pat, STRLEN patlen,
va_list *args, SV **svargs, I32 svmax,
bool *used_locale));

sv_vsetpvfn(sv, pat, patlen, args, svargs, svmax, used_locale)

Works like vcatpvfn but copies the text into the SV instead of appending it.

void sv_setpvfn _((SV* sv, const char* pat, STRLEN patlen,
va_list *args, SV **svargs, I32 svmax,
bool *used_locale));

SvUV

Returns the unsigned integer which is in the SV.

UV SvUV(SV* sv)

SvUVX

Returns the unsigned integer which is stored in the SV.

UV SvUVX(SV* sv)

PL_sv_yes

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

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++.

toLOWER

Converts the specified character to lowercase.

int toLOWER (char c)

toUPPER

Converts the specified character to uppercase.

int toUPPER (char c)

warn

This is the XSUB-writer's interface to Perl's warn function. Use this function the same way you use the C printf function. See croak().

XPUSHi

Push an integer onto the stack, extending the stack if necessary. Handles 'set' magic. See PUSHi.

XPUSHi(int d)

XPUSHn

Push a double onto the stack, extending the stack if necessary. Handles 'set' magic. See PUSHn.

XPUSHn(double d)

XPUSHp

Push a string onto the stack, extending the stack if necessary. The len indicates the length of the string. Handles 'set' magic. See PUSHp.

XPUSHp(char *c, int len)

XPUSHs

Push an SV onto the stack, extending the stack if necessary. Does not handle 'set' magic. See PUSHs.

XPUSHs(sv)

XPUSHu

Push an unsigned integer onto the stack, extending the stack if necessary. See PUSHu.

XS

Macro to declare an XSUB and its C parameter list. This is handled by xsubpp.

XSRETURN

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

XSRETURN(int x)

XSRETURN_EMPTY

Return an empty list from an XSUB immediately.

XSRETURN_EMPTY;

XSRETURN_IV

Return an integer from an XSUB immediately. Uses XST_mIV.

XSRETURN_IV(IV v)

XSRETURN_NO

Return &PL_sv_no from an XSUB immediately. Uses XST_mNO.

XSRETURN_NO;

XSRETURN_NV

Return an double from an XSUB immediately. Uses XST_mNV.

XSRETURN_NV(NV v)

XSRETURN_PV

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

XSRETURN_PV(char *v)

XSRETURN_UNDEF

Return &PL_sv_undef from an XSUB immediately. Uses XST_mUNDEF.

XSRETURN_UNDEF;

XSRETURN_YES

Return &PL_sv_yes from an XSUB immediately. Uses XST_mYES.

XSRETURN_YES;

XST_mIV

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

XST_mIV( int i, IV v )

XST_mNV

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

XST_mNV( int i, NV v )

XST_mNO

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

XST_mNO( int i )

XST_mPV

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

XST_mPV( int i, char *v )

XST_mUNDEF

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

XST_mUNDEF( int i )

XST_mYES

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

XST_mYES( int i )

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.

Zero

The XSUB-writer's interface to the C memzero function. The d is the destination, n is the number of items, and t is the type.

void Zero( d, n, t )