{
SV Scalar Value
AV Array Value
HV Hash Value
Each typedef has specific routines that manipulate the various data types.
What is an L
Perl uses a special typedef IV which is large enough to hold either an integer or a pointer.
Perl also uses two special typedefs, I32 and I16, which will always be at least 32-bits and 16-bits long, respectively.
Working with SV's
An SV can be created and loaded with one command. There are four types of values that can be loaded: an integer value (IV), a double (NV), a string, (PV), and another scalar (SV).
The four routines are:
SV* newSViv(IV);
SV* newSVnv(double);
SV* newSVpv(char*, int);
SV* newSVsv(SV*);
To change the value of an *already-existing* SV, there are five routines:
void sv_setiv(SV*, IV);
void sv_setnv(SV*, double);
void sv_setpvn(SV*, char*, int)
void sv_setpv(SV*, char*);
void sv_setsv(SV*, SV*);
Notice that you can choose to specify the length of the string to be assigned by using CWsv_setpvn or CWnewSVpv, or you may allow Perl to calculate the length by using CWsv_setpv or by specifying 0 as the second argument to CWnewSVpv. Be warned, though, that Perl will determine the string's length by using CWstrlen, which depends on the string terminating with a NUL character.
To access the actual value that an SV points to, you can use the macros:
SvIV(SV*)
SvNV(SV*)
SvPV(SV*, STRLEN len)
which will automatically coerce the actual scalar type into an IV, double, or string.
In the CWSvPV macro, the length of the string returned is placed into the variable CWlen (this is a macro, so you do not use CW&len). If you do not care what the length of the data is, use the global variable CWna. Remember, however, that Perl allows arbitrary strings of data that may both contain NUL's and not be terminated by a NUL.
If you simply want to know if the scalar value is TRUE, you can use:
SvTRUE(SV*)
Although Perl will automatically grow strings for you, if you need to force Perl to allocate more memory for your SV, you can use the macro
SvGROW(SV*, STRLEN newlen)
which will determine if more memory needs to be allocated. If so, it will call the function CWsv_grow. Note that CWSvGROW can only increase, not decrease, the allocated memory of an SV.
If you have an SV and want to know what kind of data Perl thinks is stored in it, you can use the following macros to check the type of SV you have.
SvIOK(SV*)
SvNOK(SV*)
SvPOK(SV*)
You can get and set the current length of the string stored in an SV with the following macros:
SvCUR(SV*)
SvCUR_set(SV*, I32 val)
You can also get a pointer to the end of the string stored in the SV with the macro:
SvEND(SV*)
But note that these last three macros are valid only if CWSvPOK() is true.
If you want to append something to the end of string stored in an CWSV*, you can use the following functions:
void sv_catpv(SV*, char*);
void sv_catpvn(SV*, char*, int);
void sv_catsv(SV*, SV*);
The first function calculates the length of the string to be appended by using CWstrlen. In the second, you specify the length of the string yourself. The third function extends the string stored in the first SV with the string stored in the second SV. It also forces the second SV to be interpreted as a string.
If you know the name of a scalar variable, you can get a pointer to its SV by using the following:
SV* perl_get_sv("varname", FALSE);
This returns NULL if the variable does not exist.
If you want to know if this variable (or any other SV) is actually CWdefined, you can call:
SvOK(SV*)
The scalar CWundef value is stored in an SV instance called CWsv_undef. Its address can be used whenever an CWSV* is needed.
There are also the two values CWsv_yes and CWsv_no, which contain Boolean TRUE and FALSE values, respectively. Like CWsv_undef, their addresses can be used whenever an CWSV* is needed.
Do not be fooled into thinking that CW(SV *) 0 is the same as CW&sv_undef. Take this code:
SV* sv = (SV*) 0;
if (I-am-to-return-a-real-value) {
sv = sv_2mortal(newSViv(42));
}
sv_setsv(ST(0), sv);
This code tries to return a new SV (which contains the value 42) if it should return a real value, or undef otherwise. Instead it has returned a null pointer which, somewhere down the line, will cause a segmentation violation, or just weird results. Change the zero to CW&sv_undef in the first line and all will be well.
To free an SV that you've created, call CWSvREFCNT_dec(SV*). Normally this call is not necessary. See the section on MORTALITY.
What's Really Stored in an SV?
Recall that the usual method of determining the type of scalar you have is to use CWSv*OK macros. Since a scalar can be both a number and a string, usually these macros will always return TRUE and calling the CWSv*V macros will do the appropriate conversion of string to integer/double or integer/double to string.
If you really need to know if you have an integer, double, or string pointer in an SV, you can use the following three macros instead:
SvIOKp(SV*)
SvNOKp(SV*)
SvPOKp(SV*)
These will tell you if you truly have an integer, double, or string pointer stored in your SV. The ``p'' stands for private.
In general, though, it's best to just use the CWSv*V macros.
Working with AV's
There are two ways to create and load an AV. The first method just creates an empty AV:
AV* newAV();
The second method both creates the AV and initially populates it with SV's:
AV* av_make(I32 num, SV **ptr);
The second argument points to an array containing CWnum CWSV*'s. Once the AV has been created, the SV's can be destroyed, if so desired.
Once the AV has been created, the following operations are possible on AV's:
void av_push(AV*, SV*);
SV* av_pop(AV*);
SV* av_shift(AV*);
void av_unshift(AV*, I32 num);
These should be familiar operations, with the exception of CWav_unshift. This routine adds CWnum elements at the front of the array with the CWundef value. You must then use CWav_store (described below) to assign values to these new elements.
Here are some other functions:
I32 av_len(AV*); /* Returns highest index value in array */
SV** av_fetch(AV*, I32 key, I32 lval);
/* Fetches value at key offset, but it stores an undef value
at the offset if lval is non-zero */
SV** av_store(AV*, I32 key, SV* val);
/* Stores val at offset key */
Take note that CWav_fetch and CWav_store return CWSV**'s, not CWSV*'s.
void av_clear(AV*);
/* Clear out all elements, but leave the array */
void av_undef(AV*);
/* Undefines the array, removing all elements */
void av_extend(AV*, I32 key);
/* Extend the array to a total of key elements */
If you know the name of an array variable, you can get a pointer to its AV by using the following:
AV* perl_get_av("varname", FALSE);
This returns NULL if the variable does not exist.
Working with HV's
To create an HV, you use the following routine:
HV* newHV();
Once the HV has been created, the following operations are possible on HV's:
SV** hv_store(HV*, char* key, U32 klen, SV* val, U32 hash);
SV** hv_fetch(HV*, char* key, U32 klen, I32 lval);
The CWklen parameter is the length of the key being passed in. The CWval argument contains the SV pointer to the scalar being stored, and CWhash is the pre-computed hash value (zero if you want CWhv_store to calculate it for you). The CWlval parameter indicates whether this fetch is actually a part of a store operation.
Remember that CWhv_store and CWhv_fetch return CWSV**'s and not just CWSV*. In order to access the scalar value, you must first dereference the return value. However, you should check to make sure that the return value is not NULL before dereferencing it.
These two functions check if a hash table entry exists, and deletes it.
bool hv_exists(HV*, char* key, U32 klen);
SV* hv_delete(HV*, char* key, U32 klen, I32 flags);
And more miscellaneous functions:
void hv_clear(HV*);
/* Clears all entries in hash table */
void hv_undef(HV*);
/* Undefines the hash table */
Perl keeps the actual data in linked list of structures with a typedef of HE. These contain the actual key and value pointers (plus extra administrative overhead). The key is a string pointer; the value is an CWSV*. However, once you have an CWHE*, to get the actual key and value, use the routines specified below.
I32 hv_iterinit(HV*);
/* Prepares starting point to traverse hash table */
HE* hv_iternext(HV*);
/* Get the next entry, and return a pointer to a
structure that has both the key and value */
char* hv_iterkey(HE* entry, I32* retlen);
/* Get the key from an HE structure and also return
the length of the key string */
SV* hv_iterval(HV*, HE* entry);
/* Return a SV pointer to the value of the HE
structure */
SV* hv_iternextsv(HV*, char** key, I32* retlen);
/* This convenience routine combines hv_iternext,
hv_iterkey, and hv_iterval. The key and retlen
arguments are return values for the key and its
length. The value is returned in the SV* argument */
If you know the name of a hash variable, you can get a pointer to its HV by using the following:
HV* perl_get_hv("varname", FALSE);
This returns NULL if the variable does not exist.
The hash algorithm, for those who are interested, is:
i = klen;
hash = 0;
s = key;
while (i--)
hash = hash * 33 + *s++;
References
References are a special type of scalar that point to other data types (including references).
To create a reference, use the following command:
SV* newRV((SV*) thing);
The CWthing argument can be any of an CWSV*, CWAV*, or CWHV*. Once you have a reference, you can use the following macro to dereference the reference:
SvRV(SV*)
then call the appropriate routines, casting the returned CWSV* to either an CWAV* or CWHV*, if required.
To determine if an SV is a reference, you can use the following macro:
SvROK(SV*)
To actually discover what the reference refers to, you must use the following macro and then check the value returned.
SvTYPE(SvRV(SV*))
The most useful types that will be returned are:
SVt_IV Scalar
SVt_NV Scalar
SVt_PV Scalar
SVt_PVAV Array
SVt_PVHV Hash
SVt_PVCV Code
SVt_PVMG Blessed Scalar
Blessed References and Class Objects
References are also used to support object-oriented programming. In the OO lexicon, an object is simply a reference that has been blessed into a package (or class). Once blessed, the programmer may now use the reference to access the various methods in the class.
A reference can be blessed into a package with the following function:
SV* sv_bless(SV* sv, HV* stash);
The CWsv argument must be a reference. The CWstash argument specifies which class the reference will belong to. See the section on the Stashes manpage for information on converting class names into stashes.
/* Still under construction */
Upgrades rv to reference if not already one. Creates new SV for rv to point to. If classname is non-null, the SV is blessed into the specified class. SV is returned.
SV* newSVrv(SV* rv, char* classname);
Copies integer or double into an SV whose reference is rv. SV is blessed if classname is non-null.
SV* sv_setref_iv(SV* rv, char* classname, IV iv);
SV* sv_setref_nv(SV* rv, char* classname, NV iv);
Copies pointer (not a string!) into an SV whose reference is rv. SV is blessed if classname is non-null.
SV* sv_setref_pv(SV* rv, char* classname, PV iv);
Copies string into an SV whose reference is rv. Set length to 0 to let Perl calculate the string length. SV is blessed if classname is non-null.
SV* sv_setref_pvn(SV* rv, char* classname, PV iv, int length);
int sv_isa(SV* sv, char* name);
int sv_isobject(SV* sv);
SV* perl_get_sv("varname", TRUE);
AV* perl_get_av("varname", TRUE);
HV* perl_get_hv("varname", TRUE);
Notice the use of TRUE as the second parameter. The new variable can now be set, using the routines appropriate to the data type.
There are additional bits that may be OR'ed with the TRUE argument to enable certain extra features. Those bits are:
0x02 Marks the variable as multiply defined, thus preventing the
"Indentifier <varname> used only once: possible typo" warning.
0x04 Issues a "Had to create <varname> unexpectedly" warning if
the variable didn't actually exist. This is useful if
you expected the variable to already exist and want to propagate
this warning back to the user.
If the CWvarname argument does not contain a package specifier, it is created in the current package.
The stack arguments are accessible through the CWST(n) macro, which returns the CWn'th stack argument. Argument 0 is the first argument passed in the Perl subroutine call. These arguments are CWSV*, and can be used anywhere an CWSV* is used.
Most of the time, output from the C routine can be handled through use of the RETVAL and OUTPUT directives. However, there are some cases where the argument stack is not already long enough to handle all the return values. An example is the POSIX tzname() call, which takes no arguments, but returns two, the local timezone's standard and summer time abbreviations.
To handle this situation, the PPCODE directive is used and the stack is extended using the macro:
EXTEND(sp, num);
where CWsp is the stack pointer, and CWnum is the number of elements the stack should be extended by.
Now that there is room on the stack, values can be pushed on it using the macros to push IV's, doubles, strings, and SV pointers respectively:
PUSHi(IV)
PUSHn(double)
PUSHp(char*, I32)
PUSHs(SV*)
And now the Perl program calling CWtzname, the two values will be assigned as in:
($standard_abbrev, $summer_abbrev) = POSIX::tzname;
An alternate (and possibly simpler) method to pushing values on the stack is to use the macros:
XPUSHi(IV)
XPUSHn(double)
XPUSHp(char*, I32)
XPUSHs(SV*)
These macros automatically adjust the stack for you, if needed.
For more information, consult the perlxs manpage.
Add cruft about reference counts. int SvREFCNT(SV* sv); void SvREFCNT_inc(SV* sv); void SvREFCNT_dec(SV* sv);
In the above example with CWtzname, we needed to create two new SV's to push onto the argument stack, that being the two strings. However, we don't want these new SV's to stick around forever because they will eventually be copied into the SV's that hold the two scalar variables.
An SV (or AV or HV) that is ``mortal'' acts in all ways as a normal ``immortal'' SV, AV, or HV, but is only valid in the ``current context''. When the Perl interpreter leaves the current context, the mortal SV, AV, or HV is automatically freed. Generally the ``current context'' means a single Perl statement.
To create a mortal variable, use the functions:
SV* sv_newmortal()
SV* sv_2mortal(SV*)
SV* sv_mortalcopy(SV*)
The first call creates a mortal SV, the second converts an existing SV to a mortal SV, the third creates a mortal copy of an existing SV.
The mortal routines are not just for SV's -- AV's and HV's can be made mortal by passing their address (and casting them to CWSV*) to the CWsv_2mortal or CWsv_mortalcopy routines.
>From Ilya: Beware that the sv_2mortal() call is eventually equivalent to svREFCNT_dec(). A value can happily be mortal in two different contexts, and it will be svREFCNT_dec()ed twice, once on exit from these contexts. It can also be mortal twice in the same context. This means that you should be very careful to make a value mortal exactly as many times as it is needed. The value that go to the Perl stack should be mortal.
You should be careful about creating mortal variables. It is possible for strange things to happen should you make the same value mortal within multiple contexts.
Scalar Value
Array Value
Hash Value
File Handle
Directory Handle
Format
Subroutine
Perl stores various stashes in a separate GV structure (for global variable) but represents them with an HV structure. The keys in this larger GV are the various package names; the values are the CWGV*'s which are stashes. It may help to think of a stash purely as an HV, and that the term ``GV'' means the global variable hash.
To get the stash pointer for a particular package, use the function:
HV* gv_stashpv(char* name, I32 create)
HV* gv_stashsv(SV*, I32 create)
The first function takes a literal string, the second uses the string stored in the SV. Remember that a stash is just a hash table, so you get back an CWHV*. The CWcreate flag will create a new package if it is set.
The name that CWgv_stash*v wants is the name of the package whose symbol table you want. The default package is called CWmain. If you have multiply nested packages, pass their names to CWgv_stash*v, separated by CW:: as in the Perl language itself.
Alternately, if you have an SV that is a blessed reference, you can find out the stash pointer by using:
HV* SvSTASH(SvRV(SV*));
then use the following to get the package name itself:
char* HvNAME(HV* stash);
If you need to return a blessed value to your Perl script, you can use the following function:
SV* sv_bless(SV*, HV* stash)
where the first argument, an CWSV*, must be a reference, and the second argument is a stash. The returned CWSV* can now be used in the same way as any other SV.
For more information on references and blessings, consult the perlref manpage.
# Version 6, 1995/1/27
Any SV may be magical, that is, it has special features that a normal SV does not have. These features are stored in the SV structure in a linked list of CWstruct magic's, typedef'ed to CWMAGIC.
struct magic {
MAGIC* mg_moremagic;
MGVTBL* mg_virtual;
U16 mg_private;
char mg_type;
U8 mg_flags;
SV* mg_obj;
char* mg_ptr;
I32 mg_len;
};
Note this is current as of patchlevel 0, and could change at any time.
Assigning Magic
Perl adds magic to an SV using the sv_magic function:
void sv_magic(SV* sv, SV* obj, int how, char* name, I32 namlen);
The CWsv argument is a pointer to the SV that is to acquire a new magical feature.
If CWsv is not already magical, Perl uses the CWSvUPGRADE macro to set the CWSVt_PVMG flag for the CWsv. Perl then continues by adding it to the beginning of the linked list of magical features. Any prior entry of the same type of magic is deleted. Note that this can be overriden, and multiple instances of the same type of magic can be associated with an SV.
The CWname and CWnamlem arguments are used to associate a string with the magic, typically the name of a variable. CWnamlem is stored in the CWmg_len field and if CWname is non-null and CWnamlem >= 0 a malloc'd copy of the name is stored in CWmg_ptr field.
The sv_magic function uses CWhow to determine which, if any, predefined ``Magic Virtual Table'' should be assigned to the CWmg_virtual field. See the ``Magic Virtual Table'' section below. The CWhow argument is also stored in the CWmg_type field.
The CWobj argument is stored in the CWmg_obj field of the CWMAGIC structure. If it is not the same as the CWsv argument, the reference count of the CWobj object is incremented. If it is the same, or if the CWhow argument is ``#'', or if it is a null pointer, then CWobj is merely stored, without the reference count being incremented.
There is also a function to add magic to an CWHV:
void hv_magic(HV *hv, GV *gv, int how);
This simply calls CWsv_magic and coerces the CWgv argument into an CWSV.
To remove the magic from an SV, call the function sv_unmagic:
void sv_unmagic(SV *sv, int type);
The CWtype argument should be equal to the CWhow value when the CWSV was initially made magical.
Magic Virtual Tables
The CWmg_virtual field in the CWMAGIC structure is a pointer to a CWMGVTBL, which is a structure of function pointers and stands for ``Magic Virtual Table'' to handle the various operations that might be applied to that variable.
The CWMGVTBL has five pointers to the following routine types:
int (*svt_get)(SV* sv, MAGIC* mg);
int (*svt_set)(SV* sv, MAGIC* mg);
U32 (*svt_len)(SV* sv, MAGIC* mg);
int (*svt_clear)(SV* sv, MAGIC* mg);
int (*svt_free)(SV* sv, MAGIC* mg);
This MGVTBL structure is set at compile-time in CWperl.h and there are currently 19 types (or 21 with overloading turned on). These different structures contain pointers to various routines that perform additional actions depending on which function is being called.
Function pointer Action taken
---------------- ------------
svt_get Do something after the value of the SV is retrieved.
svt_set Do something after the SV is assigned a value.
svt_len Report on the SV's length.
svt_clear Clear something the SV represents.
svt_free Free any extra storage associated with the SV.
For instance, the MGVTBL structure called CWvtbl_sv (which corresponds to an CWmg_type of '\0') contains:
{ magic_get, magic_set, magic_len, 0, 0 }
Thus, when an SV is determined to be magical and of type '\0', if a get operation is being performed, the routine CWmagic_get is called. All the various routines for the various magical types begin with CWmagic_.
The current kinds of Magic Virtual Tables are:
mg_type MGVTBL Type of magicalness
------- ------ -------------------
\0 vtbl_sv Regexp???
A vtbl_amagic Operator Overloading
a vtbl_amagicelem Operator Overloading
c 0 Used in Operator Overloading
B vtbl_bm Boyer-Moore???
E vtbl_env %ENV hash
e vtbl_envelem %ENV hash element
g vtbl_mglob Regexp /g flag???
I vtbl_isa @ISA array
i vtbl_isaelem @ISA array element
L 0 (but sets RMAGICAL) Perl Module/Debugger???
l vtbl_dbline Debugger?
P vtbl_pack Tied Array or Hash
p vtbl_packelem Tied Array or Hash element
q vtbl_packelem Tied Scalar or Handle
S vtbl_sig Signal Hash
s vtbl_sigelem Signal Hash element
t vtbl_taint Taintedness
U vtbl_uvar ???
v vtbl_vec Vector
x vtbl_substr Substring???
* vtbl_glob GV???
# vtbl_arylen Array Length
. vtbl_pos $. scalar variable
~ Reserved for extensions, but multiple extensions may clash
When an upper-case and lower-case letter both exist in the table, then the upper-case letter is used to represent some kind of composite type (a list or a hash), and the lower-case letter is used to represent an element of that composite type.
Finding Magic
MAGIC* mg_find(SV*, int type); /* Finds the magic pointer of that type */
This routine returns a pointer to the CWMAGIC structure stored in the SV. If the SV does not have that magical feature, CWNULL is returned. Also, if the SV is not of type SVt_PVMG, Perl may core-dump.
int mg_copy(SV* sv, SV* nsv, char* key, STRLEN klen);
This routine checks to see what types of magic CWsv has. If the mg_type field is an upper-case letter, then the mg_obj is copied to CWnsv, but the mg_type field is changed to be the lower-case letter.
Some scalar variables contain more than one type of scalar data. For example, the variable CW$! contains either the numeric value of CWerrno or its string equivalent from either CWstrerror or CWsys_errlist[].
To force multiple data values into an SV, you must do two things: use the CWsv_set*v routines to add the additional scalar type, then set a flag so that Perl will believe it contains more than one type of data. The four macros to set the flags are:
SvIOK_on
SvNOK_on
SvPOK_on
SvROK_on
The particular macro you must use depends on which CWsv_set*v routine you called first. This is because every CWsv_set*v routine turns on only the bit for the particular type of data being set, and turns off all the rest.
For example, to create a new Perl variable called ``dberror'' that contains both the numeric and descriptive string error values, you could use the following code:
extern int dberror;
extern char *dberror_list;
SV* sv = perl_get_sv("dberror", TRUE);
sv_setiv(sv, (IV) dberror);
sv_setpv(sv, dberror_list[dberror]);
SvIOK_on(sv);
If the order of CWsv_setiv and CWsv_setpv had been reversed, then the macro CWSvPOK_on would need to be called instead of CWSvIOK_on.
I32 perl_call_sv(SV*, I32);
I32 perl_call_pv(char*, I32);
I32 perl_call_method(char*, I32);
I32 perl_call_argv(char*, I32, register char**);
The routine most often used is CWperl_call_sv. The CWSV* argument contains either the name of the Perl subroutine to be called, or a reference to the subroutine. The second argument consists of flags that control the context in which the subroutine is called, whether or not the subroutine is being passed arguments, how errors should be trapped, and how to treat return values.
All four routines return the number of arguments that the subroutine returned on the Perl stack.
When using any of these routines (except CWperl_call_argv), the programmer must manipulate the Perl stack. These include the following macros and functions:
dSP
PUSHMARK()
PUTBACK
SPAGAIN
ENTER
SAVETMPS
FREETMPS
LEAVE
XPUSH*()
POP*()
For more information, consult the perlcall manpage.
New(x, pointer, number, type);
Newc(x, pointer, number, type, cast);
Newz(x, pointer, number, type);
These three macros are used to initially allocate memory. The first argument CWx was a ``magic cookie'' that was used to keep track of who called the macro, to help when debugging memory problems. However, the current code makes no use of this feature (Larry has switched to using a run-time memory checker), so this argument can be any number.
The second argument CWpointer will point to the newly allocated memory. The third and fourth arguments CWnumber and CWtype specify how many of the specified type of data structure should be allocated. The argument CWtype is passed to CWsizeof. The final argument to CWNewc, CWcast, should be used if the CWpointer argument is different from the CWtype argument.
Unlike the CWNew and CWNewc macros, the CWNewz macro calls CWmemzero to zero out all the newly allocated memory.
Renew(pointer, number, type);
Renewc(pointer, number, type, cast);
Safefree(pointer)
These three macros are used to change a memory buffer size or to free a piece of memory no longer needed. The arguments to CWRenew and CWRenewc match those of CWNew and CWNewc with the exception of not needing the ``magic cookie'' argument.
Move(source, dest, number, type);
Copy(source, dest, number, type);
Zero(dest, number, type);
These three macros are used to move, copy, or zero out previously allocated memory. The CWsource and CWdest arguments point to the source and destination starting points. Perl will move, copy, or zero out CWnumber instances of the size of the CWtype data structure (using the CWsizeof function).
void av_clear _((AV* ar));
void av_extend _((AV* ar, I32 key));
SV** av_fetch _((AV* ar, I32 key, I32 lval));
I32 av_len _((AV* ar));
AV* av_make _((I32 size, SV** svp));
SV* av_pop _((AV* ar));
void av_push _((AV* ar, SV* val));
SV* av_shift _((AV* ar));
SV** av_store _((AV* ar, I32 key, SV* val));
void av_undef _((AV* ar));
void av_unshift _((AV* ar, I32 num));
(void) Copy( s, d, n, t );
HV * CvSTASH( SV* sv )
SvPV( GvSV( DBsub ), na )
ENTER;
EXTEND( sp, int x );
FREETMPS;
HV* gv_stashpv _((char* name, I32 create));
HV* gv_stashsv _((SV* sv, I32 create));
void hv_clear _((HV* tb));
SV* hv_delete _((HV* tb, char* key, U32 klen, I32 flags));
bool hv_exists _((HV* tb, char* key, U32 klen));
SV** hv_fetch _((HV* tb, char* key, U32 klen, I32 lval));
I32 hv_iterinit _((HV* tb));
char* hv_iterkey _((HE* entry, I32* retlen));
HE* hv_iternext _((HV* tb));
SV * hv_iternextsv _((HV* hv, char** key, I32* retlen));
SV* hv_iterval _((HV* tb, HE* entry));
void hv_magic _((HV* hv, GV* gv, int how));
char *HvNAME (HV* stash)
SV** hv_store _((HV* tb, char* key, U32 klen, SV* val, U32 hash));
void hv_undef _((HV* tb));
int isALNUM (char c)
int isALPHA (char c)
int isDIGIT (char c)
int isLOWER (char c)
int isSPACE (char c)
int isUPPER (char c)
LEAVE;
int mg_clear _((SV* sv));
int mg_copy _((SV *, SV *, char *, STRLEN));
MAGIC* mg_find _((SV* sv, int type));
int mg_free _((SV* sv));
int mg_get _((SV* sv));
U32 mg_len _((SV* sv));
void mg_magical _((SV* sv));
int mg_set _((SV* sv));
(void) Move( s, d, n, t );
void * New( x, void *ptr, int size, type )
void * Newc( x, void *ptr, int size, type, cast )
void * Newz( x, void *ptr, int size, type )
AV* newAV _((void));
HV* newHV _((void));
SV* newRV _((SV* ref));
SV* newSV _((STRLEN len));
SV* newSViv _((IV i));
SV* newSVnv _((NV i));
SV* newSVpv _((char* s, STRLEN len));
SV* newSVrv _((SV* rv, char* classname));
SV* newSVsv _((SV* old));
I32 perl_call_argv _((char* subname, I32 flags, char** argv));
I32 perl_call_method _((char* methname, I32 flags));
I32 perl_call_pv _((char* subname, I32 flags));
I32 perl_call_sv _((SV* sv, I32 flags));
I32 perl_eval_sv _((SV* sv, I32 flags));
AV* perl_get_av _((char* name, I32 create));
CV* perl_get_cv _((char* name, I32 create));
HV* perl_get_hv _((char* name, I32 create));
SV* perl_get_sv _((char* name, I32 create));
void perl_require_pv _((char* pv));
int POPi();
long POPl();
char * POPp();
double POPn();
SV* POPs();
PUSHMARK(p)
PUSHi(int d)
PUSHn(double d)
PUSHp(char *c, int len )
PUSHs(sv)
PUTBACK;
void * Renew( void *ptr, int size, type )
void * Renewc( void *ptr, int size, type, cast )
char* savepv _((char* sv));
char* savepvn _((char* sv, I32 len));
SAVETMPS;
SPAGAIN;
SV* ST(int x)
int strEQ( char *s1, char *s2 )
int strGE( char *s1, char *s2 )
int strGT( char *s1, char *s2 )
int strLE( char *s1, char *s2 )
int strLT( char *s1, char *s2 )
int strNE( char *s1, char *s2 )
int strnEQ( char *s1, char *s2 )
int strnNE( char *s1, char *s2, int len )
SV* sv_2mortal _((SV* sv));
SV* sv_bless _((SV* sv, HV* stash));
void sv_catpv _((SV* sv, char* ptr));
void sv_catpvn _((SV* sv, char* ptr, STRLEN len));
void sv_catsv _((SV* dsv, SV* ssv));
int SvCUR (SV* sv)
SvCUR_set (SV* sv, int val )
*SvEND(sv)
char * SvGROW( SV* sv, int len )
int SvIOK (SV* SV)
SvIOK_off (SV* sv)
SvIOK_on (SV* sv)
int SvIOKp (SV* SV)
int sv_isa _((SV* sv, char* name));
int SvIV (SV* sv)
int sv_isobject _((SV* sv));
int SvIVX (SV* sv);
int SvLEN (SV* sv)
void sv_magic _((SV* sv, SV* obj, int how, char* name, I32 namlen));
SV* sv_mortalcopy _((SV* oldsv));
int SvOK (SV* sv)
SV* sv_newmortal _((void));
int SvNIOK (SV* SV)
SvNIOK_off (SV* sv)
int SvNIOKp (SV* SV)
int SvNOK (SV* SV)
SvNOK_off (SV* sv)
SvNOK_on (SV* sv)
int SvNOKp (SV* SV)
double SvNV (SV* sv);
double SvNVX (SV* sv);
int SvPOK (SV* SV)
SvPOK_off (SV* sv)
SvPOK_on (SV* sv)
int SvPOKp (SV* SV)
char * SvPV (SV* sv, int len )
char * SvPVX (SV* sv)
int SvREFCNT (SV* sv);
void SvREFCNT_dec (SV* sv)
void SvREFCNT_inc (SV* sv)
int SvROK (SV* sv)
SvROK_off (SV* sv)
SvROK_on (SV* sv)
SV* SvRV (SV* sv);
void sv_setiv _((SV* sv, IV num));
void sv_setnv _((SV* sv, double num));
void sv_setpv _((SV* sv, char* ptr));
void sv_setpvn _((SV* sv, char* ptr, STRLEN len));
SV* sv_setref_iv _((SV *rv, char *classname, IV iv));
SV* sv_setref_nv _((SV *rv, char *classname, double nv));
SV* sv_setref_pv _((SV *rv, char *classname, void* pv));
Do not use with integral Perl types such as HV, AV, SV, CV, because those objects will become corrupted by the pointer copy process.
Note that CWsv_setref_pvn copies the string while this copies the pointer.
SV* sv_setref_pvn _((SV *rv, char *classname, char* pv, I32 n));
Note that CWsv_setref_pv copies the pointer while this copies the string.
void sv_setsv _((SV* dsv, SV* ssv));
HV * SvSTASH (SV* sv)
int SvTRUE (SV* sv)
svtype SvTYPE (SV* sv)
void sv_usepvn _((SV* sv, char* ptr, STRLEN len));
int toLOWER (char c)
int toUPPER (char c)
XPUSHi(int d)
XPUSHn(double d)
XPUSHp(char *c, int len)
XPUSHs(sv)
XSRETURN(x);
XSRETURN_EMPTY;
XSRETURN_NO;
XSRETURN_UNDEF;
XSRETURN_YES;
(void) Zero( d, n, t );
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, and Spider Boardman.
API Listing by Dean Roehrich <roehrich@cray.com>.