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Chapter 8 Standard Modules |
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The standard Perl interface to the dynamic linking mechanisms available on many platforms.
Use DynaLoader like this:
Thepackage Module ; require DynaLoader; @ISA = qw(... DynaLoader ...); bootstrap Module ;
bootstrap
method calls your module's bootstrap routine directly if the module is statically linked into Perl. Otherwise the module inherits the
bootstrap
method from DynaLoader, which loads in your module and calls its
bootstrap
method.
If you want to extend DynaLoader to a new architecture, you need to know about its internal interface. The variables it uses are:
$dl_debug
Enables internal debugging messages on the Perl side of the DynaLoader; by default, is set to
$ENV{'PERL_DL_DEBUG'}
if that is defined. A similar debugging variable is added to the C code (see
dlutils.c
) and enabled if Perl was built with the
-DDEBUGGING
flag, or it can be set via the
PERL_DL_DEBUG
environment variable. Set to
1
for minimal information or higher for more detail.
@dl_library_path
Default list of directories to search for libraries; initialized to hold the list of directories in
$Config{'libpth'}
. Should also be initialized with other directories that can be determined from the environment at runtime.
@dl_resolve_using
List of additional libraries or other shared objects for resolving undefined symbols. Required only on platforms without automatic handling for dependent libraries.
@dl_require_symbols
List of one or more symbol names in the library/object file to be dynamically loaded. Only required on some platforms.
Of the following subroutines,
bootstrap
and
dl_findfile
are standard across all platforms and are defined in
DynaLoader.pm
. The others are defined in the
.xs
file that supplies the implementation for the platform.
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| 8.43 DirHandle |
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8.45 English |