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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.

"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.

        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.

        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.

        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_delete

Deletes the element indexed by key from the array. Returns the deleted element. flags is currently ignored.

        SV*     av_delete(AV* ar, 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.

        bool    av_exists(AV* ar, I32 key)
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 perlguts for more information on how to use this function on tied arrays.

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

Ensure than an array has a given number of elements, equivalent to Perl's $#array = $fill;.

        void    av_fill(AV* ar, I32 fill)
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 perlguts 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)
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)
newAV

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

        AV*     newAV()
Nullav

Null AV pointer.

sortsv

Sort an array. Here is an example:

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

See lib/sort.pm for details about controlling the sorting algorithm.

        void    sortsv(SV ** array, size_t num_elts, SVCOMPARE_t cmp)

Callback Functions ^

call_argv

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

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 perlcall.

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 perlcall.

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 perlcall.

NOTE: the perl_ form of this function is deprecated.

        I32     call_sv(SV* sv, I32 flags)
ENTER

Opening bracket on a callback. See LEAVE and perlcall.

                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)
FREETMPS

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

                FREETMPS;
LEAVE

Closing bracket on a callback. See ENTER and perlcall.

                LEAVE;
SAVETMPS

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

                SAVETMPS;

Character classes ^

isALNUM

Returns a boolean indicating whether the C char is an ASCII alphanumeric character (including underscore) 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)
toLOWER

Converts the specified character to lowercase.

        char    toLOWER(char ch)
toUPPER

Converts the specified character to uppercase.

        char    toUPPER(char ch)

Cloning an interpreter ^

perl_clone

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

        PerlInterpreter*        perl_clone(PerlInterpreter* interp, UV flags)

CV Manipulation Functions ^

CvSTASH

Returns the stash of the CV.

        HV*     CvSTASH(CV* cv)
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)
Nullcv

Null CV pointer.

Embedding Functions ^

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.

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

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

        int     nothreadhook()
perl_alloc

Allocates a new Perl interpreter. See perlembed.

        PerlInterpreter*        perl_alloc()
perl_construct

Initializes a new Perl interpreter. See perlembed.

        void    perl_construct(PerlInterpreter* interp)
perl_destruct

Shuts down a Perl interpreter. See perlembed.

        int     perl_destruct(PerlInterpreter* interp)
perl_free

Releases a Perl interpreter. See perlembed.

        void    perl_free(PerlInterpreter* interp)
perl_parse

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

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

Tells a Perl interpreter to run. See perlembed.

        int     perl_run(PerlInterpreter* interp)
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 Perl_load_module instead.

NOTE: the perl_ form of this function is deprecated.

        void    require_pv(const char* pv)

Functions in file pp_pack.c ^

pack_cat

The engine implementing pack() Perl function.

        void    pack_cat(SV *cat, char *pat, char *patend, SV **beglist, SV **endlist, SV ***next_in_list, U32 flags)
unpack_str

The engine implementing unpack() Perl function.

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

Global 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.

        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

GV Functions ^

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_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.

        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. 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)

Handy Values ^

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).

Nullch

Null character pointer. =for hackers Found in file handy.h

Nullsv

Null SV pointer.

Hash Manipulation Functions ^

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)
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, 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.

        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, 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.

        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 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.

        SV**    hv_fetch(HV* tb, const char* key, I32 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 perlguts 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.

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.

        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_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 literally <&Perl_sv_undef> (a regular undef value is a normal read-write SV for which !SvOK is false). 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.

        HE*     hv_iternext_flags(HV* tb, I32 flags)
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 perlguts for more information on how to use this function on tied hashes.

        SV**    hv_store(HV* tb, const char* key, I32 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 perlguts 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)
newHV

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

        HV*     newHV()
Nullhv

Null HV pointer.

Magical Functions ^

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)
SvGETMAGIC

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

        void    SvGETMAGIC(SV* sv)
SvLOCK

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

        void    SvLOCK(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)
SvSetMagicSV

Like SvSetSV, but does any set magic required afterwards.

        void    SvSetMagicSV(SV* dsb, SV* ssv)
SvSetMagicSV_nosteal

Like SvSetMagicSV, but does any set magic required afterwards.

        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.

        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)
SvSHARE

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

        void    SvSHARE(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.

        void    Copy(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.

        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)
Newc

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

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

Fill up memory with a pattern (byte 0xAB over and over again) that hopefully catches attempts to access uninitialized memory.

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

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

        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.

        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. The memory allocated for the new string can be freed with the Safefree() function.

        char*   savepvn(const char* pv, I32 len)
savesharedpv

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

        char*   savesharedpv(const char* pv)
StructCopy

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

        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.

        void    Zero(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.

        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)
form

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

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

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

    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).

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

Fill the sv with current working directory

        int     getcwd_sv(SV* sv)
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)

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. On return *len is set to the length 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 hex 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.

        UV      grok_bin(char* start, STRLEN* len, 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 non-hex-digit character. On return *len is set to the length 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.

        UV      grok_hex(char* start, STRLEN* len, 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.

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

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

        bool    grok_numeric_radix(const char **sp, const char *send)
grok_oct
        UV      grok_oct(char* start, STRLEN* len, I32* flags, NV *result)
scan_bin

For backwards compatibility. Use grok_bin instead.

        NV      scan_bin(char* start, STRLEN len, STRLEN* retlen)
scan_hex

For backwards compatibility. Use grok_hex instead.

        NV      scan_hex(char* start, STRLEN len, STRLEN* retlen)
scan_oct

For backwards compatibility. Use grok_oct instead.

        NV      scan_oct(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.

        SV*     cv_const_sv(CV* cv)
newCONSTSUB

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

        CV*     newCONSTSUB(HV* stash, char* name, SV* sv)
newXS

Used by xsubpp to hook up XSUBs as Perl subs.

Stack Manipulation Macros ^

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;
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.

        void    EXTEND(SP, int nitems)
MARK

Stack marker variable for the XSUB. See dMARK.

ORIGMARK

The original stack mark for the XSUB. See dORIGMARK.

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. Deprecated. New code should provide a STRLEN n_a and use POPpx.

        char*   POPp
POPpbytex

Pops a string off the stack which must consist of bytes i.e. characters < 256. Requires a variable STRLEN n_a in scope.

        char*   POPpbytex
POPpx

Pops a string off the stack. Requires a variable STRLEN n_a in scope.

        char*   POPpx
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 perlcall.

                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 perlcall for other uses.

                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.

                SPAGAIN;
XPUSHi

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

        void    XPUSHi(IV iv)
XPUSHn

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

        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. See PUSHp.

        void    XPUSHp(char* str, STRLEN len)
XPUSHs

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

        void    XPUSHs(SV* sv)
XPUSHu

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

        void    XPUSHu(UV uv)
XSRETURN

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

        void    XSRETURN(int nitems)
XSRETURN_IV

Return an integer from an XSUB immediately. Uses XST_mIV.

        void    XSRETURN_IV(IV iv)
XSRETURN_NO

Return &PL_sv_no from an XSUB immediately. Uses XST_mNO.

                XSRETURN_NO;
XSRETURN_NV

Return a double from an XSUB immediately. Uses XST_mNV.

        void    XSRETURN_NV(NV nv)
XSRETURN_PV

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

        void    XSRETURN_PV(char* str)
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 pos on the stack. The value is stored in a new mortal SV.

        void    XST_mIV(int pos, IV iv)
XST_mNO

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

        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.

        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.

        void    XST_mPV(int pos, char* str)
XST_mUNDEF

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

        void    XST_mUNDEF(int pos)
XST_mYES

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

        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 ^

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)
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.

        I32     looks_like_number(SV* sv)
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

Create a new null SV, or if len > 0, create a new empty SVt_PV type SV with an initial PV allocation of len+1. Normally accessed via the NEWSV macro.

        SV*     newSV(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 and initializes 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)
newSVpvn_share

Creates a new SV with its SvPVX 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. The string's hash is stored in the UV slot of the SV; if the hash parameter is non-zero, that value is used; otherwise the hash is computed. The idea here is that as the string table is used for shared hash keys these strings will have SvPVX == HeKEY and hash lookup will avoid string compare.

        SV*     newSVpvn_share(const char* s, I32 len, U32 hash)
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. (Uses sv_setsv).

        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)
new_vstring

Returns a pointer to the next character after the parsed vstring, as well as updating the passed in sv.

Function must be called like

        sv = NEWSV(92,5);
        s = new_vstring(s,sv);

The sv must already be large enough to store the vstring passed in.

        char*   new_vstring(char *vstr, SV *sv)
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)
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, 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_notUV

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

        void    SvIOK_notUV(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)
SvIOK_only_UV

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

        void    SvIOK_only_UV(SV* sv)
SvIOK_UV

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

        void    SvIOK_UV(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.

        IV      SvIV(SV* sv)
SvIVx

Coerces the given SV to an integer and returns it. Guarantees to evaluate sv only once. Use the more efficient SvIV otherwise.

        IV      SvIVx(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().

        IV      SvIVX(SV* sv)
SvLEN

Returns the size of the string buffer in the SV, not including any part attributable to SvOOK. 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. See SvNVx for a version which guarantees to evaluate sv only once.

        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().

        NV      SvNVX(SV* sv)
SvNVx

Coerces the given SV to a double and returns it. Guarantees to evaluate sv only once. Use the more efficient SvNV otherwise.

        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. Will also turn off the UTF8 status.

        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 UTF8 status as it was.

        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.

        char*   SvPV(SV* sv, STRLEN len)
SvPVbyte

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

        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.

        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.

        char*   SvPVbytex_force(SV* sv, STRLEN len)
SvPVbyte_force

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

        char*   SvPVbyte_force(SV* sv, STRLEN len)
SvPVbyte_nolen

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

        char*   SvPVbyte_nolen(SV* sv)
SvPVutf8

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

        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.

        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.

        char*   SvPVutf8x_force(SV* sv, STRLEN len)
SvPVutf8_force

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

        char*   SvPVutf8_force(SV* sv, STRLEN len)
SvPVutf8_nolen

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

        char*   SvPVutf8_nolen(SV* sv)
SvPVx

A version of SvPV which guarantees to evaluate sv only once.

        char*   SvPVx(SV* sv, STRLEN len)
SvPVX

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

        char*   SvPVX(SV* sv)
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.

        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.

        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.

        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)
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 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)
SvTRUE

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

        bool    SvTRUE(SV* sv)
SvTYPE

Returns the type of the SV. See svtype.

        svtype  SvTYPE(SV* sv)
SvUNLOCK

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

        void    SvUNLOCK(SV* sv)
SvUOK

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

        void    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.

        void    SvUPGRADE(SV* sv, svtype type)
SvUTF8

Returns a boolean indicating whether the SV contains UTF-8 encoded data.

        void    SvUTF8(SV* sv)
SvUTF8_off

Unsets the UTF8 status of an SV.

        void    SvUTF8_off(SV *sv)
SvUTF8_on

Turn on the UTF8 status of an SV (the data is not changed, just the flag). Do not use frivolously.

        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.

        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().

        UV      SvUVX(SV* sv)
SvUVx

Coerces the given SV to an unsigned integer and returns it. Guarantees to evaluate sv only once. Use the more efficient SvUV otherwise.

        UV      SvUVx(SV* sv)
sv_2bool

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

        bool    sv_2bool(SV* 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.

        CV*     sv_2cv(SV* sv, HV** st, GV** gvp, 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.

        IO*     sv_2io(SV* sv)
sv_2iv

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

        IV      sv_2iv(SV* sv)
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. See also sv_newmortal and sv_mortalcopy.

        SV*     sv_2mortal(SV* 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.

        NV      sv_2nv(SV* 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 UTF8 as a side-effect.

Usually accessed via the SvPVbyte macro.

        char*   sv_2pvbyte(SV* sv, STRLEN* lp)
sv_2pvbyte_nolen

Return a pointer to the byte-encoded representation of the SV. May cause the SV to be downgraded from UTF8 as a side-effect.

Usually accessed via the SvPVbyte_nolen macro.

        char*   sv_2pvbyte_nolen(SV* sv)
sv_2pvutf8

Return a pointer to the UTF8-encoded representation of the SV, and set *lp to its length. May cause the SV to be upgraded to UTF8 as a side-effect.

Usually accessed via the SvPVutf8 macro.

        char*   sv_2pvutf8(SV* sv, STRLEN* lp)
sv_2pvutf8_nolen

Return a pointer to the UTF8-encoded representation of the SV. May cause the SV to be upgraded to UTF8 as a side-effect.

Usually accessed via the SvPVutf8_nolen macro.

        char*   sv_2pvutf8_nolen(SV* sv)
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.

        char*   sv_2pv_flags(SV* sv, STRLEN* lp, I32 flags)
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_2uv

Return the unsigned integer value of an SV, doing any necessary string conversion, magic etc. Normally used via the SvUV(sv) and SvUVx(sv) macros.

        UV      sv_2uv(SV* sv)
sv_backoff

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

        int     sv_backoff(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. If the SV has the UTF8 status set, then the bytes appended should be valid UTF8. Handles 'get' magic, but not 'set' magic. See sv_catpv_mg.

        void    sv_catpv(SV* 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. 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_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 UTF8 status set, then the bytes appended should be valid UTF8. Handles 'get' magic, but not 'set' magic. See sv_catpvn_mg.

        void    sv_catpvn(SV* sv, const char* ptr, 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 UTF8 status set, then the bytes appended should be valid UTF8. 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.

        void    sv_catpvn_flags(SV* sv, const char* ptr, STRLEN len, I32 flags)
sv_catpvn_mg

Like sv_catpvn, but also handles 'set' magic.

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

Like sv_catpv, but also handles 'set' magic.

        void    sv_catpv_mg(SV *sv, const char *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.

        void    sv_catsv(SV* dsv, SV* ssv)
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.

        void    sv_catsv_flags(SV* dsv, SV* ssv, I32 flags)
sv_catsv_mg

Like sv_catsv, but also handles 'set' magic.

        void    sv_catsv_mg(SV *dstr, SV *sstr)
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".

        void    sv_chop(SV* sv, char* 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.

        void    sv_clear(SV* 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.

        I32     sv_cmp(SV* sv1, SV* 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_locale. See also sv_cmp.

        I32     sv_cmp_locale(SV* sv1, SV* 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.

        char*   sv_collxfrm(SV* sv, STRLEN* 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 UTF-8 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.

        void    sv_copypv(SV* dsv, SV* ssv)
sv_dec

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

        void    sv_dec(SV* sv)
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, const char* name)
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.

        I32     sv_eq(SV* sv1, SV* sv2)
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.

        void    sv_force_normal(SV *sv)
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. The flags parameter gets passed to sv_unref_flags() when unrefing. sv_force_normal calls this function with flags set to 0.

        void    sv_force_normal_flags(SV *sv, 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.

        void    sv_free(SV* sv)
sv_gets

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

        char*   sv_gets(SV* sv, PerlIO* 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.

        char*   sv_grow(SV* sv, STRLEN newlen)
sv_inc

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

        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* bigsv, STRLEN offset, STRLEN len, char* little, STRLEN littlelen)
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, const 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)
sv_iv

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

        IV      sv_iv(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.

        STRLEN  sv_len(SV* sv)
sv_len_utf8

Returns the number of characters in the string in an SV, counting wide UTF8 bytes as a single character. Handles magic and type coercion.

        STRLEN  sv_len_utf8(SV* 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.

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

Adds magic to an SV, upgrading it if necessary. Applies the supplied vtable and returns 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 and more than one instance of the same 'how'

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

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

        MAGIC * sv_magicext(SV* sv, SV* obj, int how, MGVTBL *vtbl, const char* name, 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.

        SV*     sv_mortalcopy(SV* 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.

        SV*     sv_newmortal()
sv_newref

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

        SV*     sv_newref(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.

        void    sv_nolocking(SV *)
sv_nosharing

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

        void    sv_nosharing(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.

        void    sv_nounlocking(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.

        NV      sv_nv(SV* 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 UTF8 chars. Handles magic and type coercion.

        void    sv_pos_b2u(SV* sv, I32* offsetp)
sv_pos_u2b

Converts the value pointed to by offsetp from a count of UTF8 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.

        void    sv_pos_u2b(SV* sv, I32* offsetp, I32* lenp)
sv_pv

Use the SvPV_nolen macro instead

        char*   sv_pv(SV *sv)
sv_pvbyte

Use SvPVbyte_nolen instead.

        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.

        char*   sv_pvbyten(SV *sv, STRLEN *len)
sv_pvbyten_force

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

        char*   sv_pvbyten_force(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.

        char*   sv_pvn(SV *sv, STRLEN *len)
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.

        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

        char*   sv_pvn_force_flags(SV* sv, STRLEN* lp, I32 flags)
sv_pvutf8

Use the SvPVutf8_nolen macro instead

        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.

        char*   sv_pvutf8n(SV *sv, STRLEN *len)
sv_pvutf8n_force

A private implementation of the SvPVutf8_force macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

        char*   sv_pvutf8n_force(SV* sv, STRLEN* lp)
sv_reftype

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

        char*   sv_reftype(SV* sv, 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.

        void    sv_replace(SV* sv, SV* nsv)
sv_report_used

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

        void    sv_report_used()
sv_reset

Underlying implementation for the reset Perl function. Note that the perl-level function is vaguely deprecated.

        void    sv_reset(char* s, HV* 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.

        SV*     sv_rvweaken(SV *sv)
sv_setiv

Copies an integer into the given SV, upgrading first if necessary. Does not handle 'set' magic. See also 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 i)
sv_setnv

Copies a double into the given SV, upgrading first if necessary. Does not handle 'set' magic. See also sv_setnv_mg.

        void    sv_setnv(SV* sv, NV num)
sv_setnv_mg

Like sv_setnv, but also handles 'set' magic.

        void    sv_setnv_mg(SV *sv, 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.

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

Like sv_setpvn, but also handles 'set' magic.

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

Like sv_setpv, but also handles 'set' magic.

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

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.

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

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

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

        SV*     sv_setref_uv(SV* rv, const char* classname, 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.

        void    sv_setsv(SV* dsv, SV* ssv)
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. 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.

        void    sv_setsv_flags(SV* dsv, SV* ssv, I32 flags)
sv_setsv_mg

Like sv_setsv, but also handles 'set' magic.

        void    sv_setsv_mg(SV *dstr, SV *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.

        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 u)
sv_taint

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

sv_tainted

Test an SV for taintedness. Use SvTAINTED instead. bool sv_tainted(SV* 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.

        I32     sv_true(SV *sv)
sv_unmagic

Removes all magic of type type from an SV.

        int     sv_unmagic(SV* sv, int type)
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.

        void    sv_unref(SV* sv)
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.

        void    sv_unref_flags(SV* sv, U32 flags)
sv_untaint

Untaint an SV. Use SvTAINTED_off instead. void sv_untaint(SV* 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.

        bool    sv_upgrade(SV* sv, U32 mt)
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_utf8_decode

Convert the octets in the PV from UTF-8 to chars. Scan for validity and then turn off SvUTF8 if needed so that we see characters. Used as a building block for decode_utf8 in Encode.xs

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

        bool    sv_utf8_decode(SV *sv)
sv_utf8_downgrade

Attempt to convert the PV of an SV from UTF8-encoded to byte encoding. This may not be possible if the PV contains non-byte encoding characters; if this is the 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.

        bool    sv_utf8_downgrade(SV *sv, bool fail_ok)
sv_utf8_encode

Convert the PV of an SV to UTF8-encoded, but then turn off the SvUTF8 flag so that it looks like octets again. Used as a building block for encode_utf8 in Encode.xs

        void    sv_utf8_encode(SV *sv)
sv_utf8_upgrade

Convert the PV of an SV to its UTF8-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 have hibit clear.

This is not as a general purpose byte encoding to Unicode interface: use the Encode extension for that.

        STRLEN  sv_utf8_upgrade(SV *sv)
sv_utf8_upgrade_flags

Convert the PV of an SV to its UTF8-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 have hibit clear. If flags has SV_GMAGIC bit set, will mg_get on sv if appropriate, else not. 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.

        STRLEN  sv_utf8_upgrade_flags(SV *sv, I32 flags)
sv_uv

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

        UV      sv_uv(SV* sv)
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_catpvf and sv_catpvf_mg.

        void    sv_vcatpvfn(SV* sv, const char* pat, STRLEN patlen, va_list* args, SV** svargs, I32 svmax, bool *maybe_tainted)
sv_vsetpvfn

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

Usually used via one of its frontends sv_setpvf and sv_setpvf_mg.

        void    sv_vsetpvfn(SV* sv, const char* pat, STRLEN patlen, va_list* args, SV** svargs, I32 svmax, bool *maybe_tainted)

Unicode Support ^

bytes_from_utf8

Converts a string s of length len from UTF8 into 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 contains all 7bit characters.

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

        U8*     bytes_from_utf8(U8 *s, STRLEN *len, bool *is_utf8)
bytes_to_utf8

Converts a string s of length len from ASCII into UTF8 encoding. Returns a pointer to the newly-created string, and sets len to reflect the new length.

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

        U8*     bytes_to_utf8(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 circustances. 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).

        I32     ibcmp_utf8(const char* a, char **pe1, UV l1, bool u1, const char* b, char **pe2, UV l2, bool u2)
is_utf8_char

Tests if some arbitrary number of bytes begins in a valid UTF-8 character. Note that an INVARIANT (i.e. ASCII) 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.

        STRLEN  is_utf8_char(U8 *p)
is_utf8_string

Returns true if first len bytes of the given string form a valid UTF8 string, false otherwise. Note that 'a valid UTF8 string' does not mean 'a string that contains UTF8' because a valid ASCII string is a valid UTF8 string.

        bool    is_utf8_string(U8 *s, STRLEN len)
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.

        char*   pv_uni_display(SV *dsv, U8 *spv, STRLEN len, STRLEN pvlim, UV flags)
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.

        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.

        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 SWASHGET, 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.

        UV      to_utf8_case(U8 *p, U8* ustrp, STRLEN *lenp, SV **swash, char *normal, 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_MAXLEN_FOLD+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.)

        UV      to_utf8_fold(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_MAXLEN_UCLC+1 bytes since the lowercase version may be longer than the original character (up to two characters).

The first character of the lowercased version is returned (but note, as explained above, that there may be more.)

        UV      to_utf8_lower(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_MAXLEN_UCLC+1 bytes since the titlecase version may be longer than the original character (up to two characters).

The first character of the titlecased version is returned (but note, as explained above, that there may be more.)

        UV      to_utf8_title(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_MAXLEN_UCLC+1 bytes since the uppercase version may be longer than the original character (up to two characters).

The first character of the uppercased version is returned (but note, as explained above, that there may be more.)

        UV      to_utf8_upper(U8 *p, U8* ustrp, STRLEN *lenp)
utf8n_to_uvchr

Returns the native character value of the first character in the string s which is assumed to be in UTF8 encoding; retlen will be set to the length, in bytes, of that character.

Allows length and flags to be passed to low level routine.

        UV      utf8n_to_uvchr(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 UTF8 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 UTF8 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.

        UV      utf8n_to_uvuni(U8 *s, STRLEN curlen, STRLEN* retlen, U32 flags)
utf8_distance

Returns the number of UTF8 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.

        IV      utf8_distance(U8 *a, 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.

        U8*     utf8_hop(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.

        STRLEN  utf8_length(U8* s, U8 *e)
utf8_to_bytes

Converts a string s of length len from UTF8 into 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.

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

        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 UTF8 encoding; retlen will be set to the length, in bytes, of that character.

If s does not point to a well-formed UTF8 character, zero is returned and retlen is set, if possible, to -1.

        UV      utf8_to_uvchr(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 UTF8 encoding; retlen will be set to the length, in bytes, of that character.

This function should only be used when returned UV is considered an index into the Unicode semantic tables (e.g. swashes).

If s does not point to a well-formed UTF8 character, zero is returned and retlen is set, if possible, to -1.

        UV      utf8_to_uvuni(U8 *s, STRLEN* retlen)
uvchr_to_utf8

Adds the UTF8 representation of the Native codepoint uv to the end of the string d; d should be have at least UTF8_MAXLEN+1 free bytes available. The return value is the pointer to the byte after the end of the new character. In other words,

    d = uvchr_to_utf8(d, uv);

is the recommended wide native character-aware way of saying

    *(d++) = uv;

        U8*     uvchr_to_utf8(U8 *d, UV uv)
uvuni_to_utf8_flags

Adds the UTF8 representation of the Unicode codepoint uv to the end of the string d; d should be have at least UTF8_MAXLEN+1 free bytes available. The return value is the pointer to the byte after the end of the new character. In other words,

    d = uvuni_to_utf8_flags(d, uv, flags);

or, in most cases,

    d = uvuni_to_utf8(d, uv);

(which is equivalent to)

    d = uvuni_to_utf8_flags(d, uv, 0);

is the recommended Unicode-aware way of saying

    *(d++) = uv;

        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.

        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.

        char*   CLASS
dAX

Sets up the ax variable. This is usually handled automatically by xsubpp by calling dXSARGS.

                dAX;
dITEMS

Sets up the items variable. This is usually handled automatically by xsubpp by calling dXSARGS.

                dITEMS;
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.

                dXSARGS;
dXSI32

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

                dXSI32;
items

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

        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.

        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.

        (whatever)      RETVAL
ST

Used to access elements on the XSUB's stack.

        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.

        (whatever)      THIS
XS

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

XSRETURN_EMPTY

Return an empty list from an XSUB immediately.

                XSRETURN_EMPTY;
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.

                XS_VERSION_BOOTCHECK;

Warning and Dieing ^

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, ...)
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.

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

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(1), perlxs(1), perlxstut(1), perlintern(1)

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