/ 
perl-5.9.3
River stage five • 12010 direct dependents • 33600 total dependents
/ gv.c

GV Functions

A GV is a structure which corresponds to to a Perl typeglob, ie *foo. It is a structure that holds a pointer to a scalar, an array, a hash etc, corresponding to $foo, @foo, %foo.

GVs are usually found as values in stashes (symbol table hashes) where Perl stores its global variables.

If gv is a typeglob whose subroutine entry is a constant sub eligible for inlining, or gv is a placeholder reference that would be promoted to such a typeglob, then returns the value returned by the sub. Otherwise, returns NULL.

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.

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.

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.

Returns a pointer to the stash for a specified package. name should be a valid UTF-8 string and must be null-terminated. 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.

Returns a pointer to the stash for a specified package. name should be a valid UTF-8 string. The namelen parameter indicates the length of the name, in bytes. 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.

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

Returns TRUE if given the name of a magical GV. Calls is_gv_magical.

Returns TRUE if given the name of a magical GV.

Currently only useful internally when determining if a GV should be created even in rvalue contexts.

flags is not used at present but available for future extension to allow selecting particular classes of magical variable.

Currently assumes that name is NUL terminated (as well as len being valid). This assumption is met by all callers within the perl core, which all pass pointers returned by SvPV.