perlapi.pod

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

=item hv_iterkey
X<hv_iterkey>

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

	char*	hv_iterkey(HE* entry, I32* retlen)

=for hackers
Found in file hv.c

=item hv_iterkeysv
X<hv_iterkeysv>

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

	SV*	hv_iterkeysv(HE* entry)

=for hackers
Found in file hv.c

=item hv_iternext
X<hv_iternext>

Returns entries from a hash iterator.  See C<hv_iterinit>.

You may call C<hv_delete> or C<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 C<hv_iternext>, so you must not discard
your iterator immediately else the entry will leak - call C<hv_iternext> to
trigger the resource deallocation.

	HE*	hv_iternext(HV* tb)

=for hackers
Found in file hv.c

=item hv_iternextsv
X<hv_iternextsv>

Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
operation.

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

=for hackers
Found in file hv.c

=item hv_iternext_flags
X<hv_iternext_flags>

Returns entries from a hash iterator.  See C<hv_iterinit> and C<hv_iternext>.
The C<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
C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
restricted hashes may change, and the implementation currently is
insufficiently abstracted for any change to be tidy.

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

	HE*	hv_iternext_flags(HV* tb, I32 flags)

=for hackers
Found in file hv.c

=item hv_iterval
X<hv_iterval>

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

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

=for hackers
Found in file hv.c

=item hv_magic
X<hv_magic>

Adds magic to a hash.  See C<sv_magic>.

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

=for hackers
Found in file hv.c

=item hv_scalar
X<hv_scalar>

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

	SV*	hv_scalar(HV* hv)

=for hackers
Found in file hv.c

=item hv_store
X<hv_store>

Stores an SV in a hash.  The hash key is specified as C<key> and C<klen> is
the length of the key.  The C<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 C<SV*>.  Note that the caller is
responsible for suitably incrementing the reference count of C<val> before
the call, and decrementing it if the function returned NULL.  Effectively
a successful hv_store takes ownership of one reference to C<val>.  This is
usually what you want; a newly created SV has a reference count of one, so
if all your code does is create SVs then store them in a hash, hv_store
will own the only reference to the new SV, and your code doesn't need to do
anything further to tidy up.  hv_store is not implemented as a call to
hv_store_ent, and does not create a temporary SV for the key, so if your
key data is not already in SV form then use hv_store in preference to
hv_store_ent.

See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
information on how to use this function on tied hashes.

	SV**	hv_store(HV* tb, const char* key, I32 klen, SV* val, U32 hash)

=for hackers
Found in file hv.c

=item hv_stores
X<hv_stores>

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

	SV**	hv_stores(HV* tb, const char* key, NULLOK SV* val)

=for hackers
Found in file handy.h

=item hv_store_ent
X<hv_store_ent>

Stores C<val> in a hash.  The hash key is specified as C<key>.  The C<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 C<He?> macros
described here.  Note that the caller is responsible for suitably
incrementing the reference count of C<val> before the call, and
decrementing it if the function returned NULL.  Effectively a successful
hv_store_ent takes ownership of one reference to C<val>.  This is
usually what you want; a newly created SV has a reference count of one, so
if all your code does is create SVs then store them in a hash, hv_store
will own the only reference to the new SV, and your code doesn't need to do
anything further to tidy up.  Note that hv_store_ent only reads the C<key>;
unlike C<val> it does not take ownership of it, so maintaining the correct
reference count on C<key> is entirely the caller's responsibility.  hv_store
is not implemented as a call to hv_store_ent, and does not create a temporary
SV for the key, so if your key data is not already in SV form then use
hv_store in preference to hv_store_ent.

See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
information on how to use this function on tied hashes.

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

=for hackers
Found in file hv.c

=item hv_undef
X<hv_undef>

Undefines the hash.

	void	hv_undef(HV* tb)

=for hackers
Found in file hv.c

=item newHV
X<newHV>

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

	HV*	newHV()

=for hackers
Found in file hv.c


=back

=head1 Magical Functions

=over 8

=item mg_clear
X<mg_clear>

Clear something magical that the SV represents.  See C<sv_magic>.

	int	mg_clear(SV* sv)

=for hackers
Found in file mg.c

=item mg_copy
X<mg_copy>

Copies the magic from one SV to another.  See C<sv_magic>.

	int	mg_copy(SV* sv, SV* nsv, const char* key, I32 klen)

=for hackers
Found in file mg.c

=item mg_find
X<mg_find>

Finds the magic pointer for type matching the SV.  See C<sv_magic>.

	MAGIC*	mg_find(const SV* sv, int type)

=for hackers
Found in file mg.c

=item mg_free
X<mg_free>

Free any magic storage used by the SV.  See C<sv_magic>.

	int	mg_free(SV* sv)

=for hackers
Found in file mg.c

=item mg_get
X<mg_get>

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

	int	mg_get(SV* sv)

=for hackers
Found in file mg.c

=item mg_length
X<mg_length>

Report on the SV's length.  See C<sv_magic>.

	U32	mg_length(SV* sv)

=for hackers
Found in file mg.c

=item mg_magical
X<mg_magical>

Turns on the magical status of an SV.  See C<sv_magic>.

	void	mg_magical(SV* sv)

=for hackers
Found in file mg.c

=item mg_set
X<mg_set>

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

	int	mg_set(SV* sv)

=for hackers
Found in file mg.c

=item SvGETMAGIC
X<SvGETMAGIC>

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

	void	SvGETMAGIC(SV* sv)

=for hackers
Found in file sv.h

=item SvLOCK
X<SvLOCK>

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

	void	SvLOCK(SV* sv)

=for hackers
Found in file sv.h

=item SvSETMAGIC
X<SvSETMAGIC>

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

	void	SvSETMAGIC(SV* sv)

=for hackers
Found in file sv.h

=item SvSetMagicSV
X<SvSetMagicSV>

Like C<SvSetSV>, but does any set magic required afterwards.

	void	SvSetMagicSV(SV* dsb, SV* ssv)

=for hackers
Found in file sv.h

=item SvSetMagicSV_nosteal
X<SvSetMagicSV_nosteal>

Like C<SvSetSV_nosteal>, but does any set magic required afterwards.

	void	SvSetMagicSV_nosteal(SV* dsv, SV* ssv)

=for hackers
Found in file sv.h

=item SvSetSV
X<SvSetSV>

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

	void	SvSetSV(SV* dsb, SV* ssv)

=for hackers
Found in file sv.h

=item SvSetSV_nosteal
X<SvSetSV_nosteal>

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

	void	SvSetSV_nosteal(SV* dsv, SV* ssv)

=for hackers
Found in file sv.h

=item SvSHARE
X<SvSHARE>

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

	void	SvSHARE(SV* sv)

=for hackers
Found in file sv.h

=item SvUNLOCK
X<SvUNLOCK>

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

	void	SvUNLOCK(SV* sv)

=for hackers
Found in file sv.h


=back

=head1 Memory Management

=over 8

=item Copy
X<Copy>

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

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

=for hackers
Found in file handy.h

=item CopyD
X<CopyD>

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

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

=for hackers
Found in file handy.h

=item Move
X<Move>

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

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

=for hackers
Found in file handy.h

=item MoveD
X<MoveD>

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

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

=for hackers
Found in file handy.h

=item Newx
X<Newx>

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

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

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

=for hackers
Found in file handy.h

=item Newxc
X<Newxc>

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

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

=for hackers
Found in file handy.h

=item Newxz
X<Newxz>

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

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

=for hackers
Found in file handy.h

=item Poison
X<Poison>

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

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

=for hackers
Found in file handy.h

=item PoisonFree
X<PoisonFree>

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

	void	PoisonFree(void* dest, int nitems, type)

=for hackers
Found in file handy.h

=item PoisonNew
X<PoisonNew>

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

	void	PoisonNew(void* dest, int nitems, type)

=for hackers
Found in file handy.h

=item PoisonWith
X<PoisonWith>

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

	void	PoisonWith(void* dest, int nitems, type, U8 byte)

=for hackers
Found in file handy.h

=item Renew
X<Renew>

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

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

=for hackers
Found in file handy.h

=item Renewc
X<Renewc>

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

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

=for hackers
Found in file handy.h

=item Safefree
X<Safefree>

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

	void	Safefree(void* ptr)

=for hackers
Found in file handy.h

=item savepv
X<savepv>

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

	char*	savepv(const char* pv)

=for hackers
Found in file util.c

=item savepvn
X<savepvn>

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

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

=for hackers
Found in file util.c

=item savepvs
X<savepvs>

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

	char*	savepvs(const char* s)