11 unlink "DynaLoader.pm" if -f "DynaLoader.pm";
12 open OUT, ">DynaLoader.pm" or die $!;
15 # Generated from DynaLoader.pm.PL (resolved %Config::Config values)
19 # And Gandalf said: 'Many folk like to know beforehand what is to
20 # be set on the table; but those who have laboured to prepare the
21 # feast like to keep their secret; for wonder makes the words of
24 # (Quote from Tolkien sugested by Anno Siegel.)
26 # See pod text at end of file for documentation.
27 # See also ext/DynaLoader/README in source tree for other information.
29 # Tim.Bunce@ig.co.uk, August 1994
31 $VERSION = "1.04"; # avoid typo warning
34 *AUTOLOAD = \&AutoLoader::AUTOLOAD;
36 # The following require can't be removed during maintenance
37 # releases, sadly, because of the risk of buggy code that does
38 # require Carp; Carp::croak "..."; without brackets dying
39 # if Carp hasn't been loaded in earlier compile time. :-(
40 # We'll let those bugs get found on the development track.
41 require Carp if $] < 5.00450;
44 # enable debug/trace messages from DynaLoader perl code
45 $dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug;
48 # Flags to alter dl_load_file behaviour. Assigned bits:
49 # 0x01 make symbols available for linking later dl_load_file's.
50 # (only known to work on Solaris 2 using dlopen(RTLD_GLOBAL))
51 # (ignored under VMS; effect is built-in to image linking)
53 # This is called as a class method $module->dl_load_flags. The
54 # definition here will be inherited and result on "default" loading
55 # behaviour unless a sub-class of DynaLoader defines its own version.
58 sub dl_load_flags { 0x00 }
61 # = @Config::Config{'dlext', 'dlsrc'};
64 print OUT " (\$dl_dlext, \$dlsrc) = (",
65 to_string($Config::Config{'dlext'}), ",",
66 to_string($Config::Config{'dlsrc'}), ")\n;" ;
70 # Some systems need special handling to expand file specifications
71 # (VMS support by Charles Bailey <bailey@HMIVAX.HUMGEN.UPENN.EDU>)
72 # See dl_expandspec() for more details. Should be harmless but
73 # inefficient to define on systems that don't need it.
74 $do_expand = $Is_VMS = $^O eq 'VMS';
75 $Is_MacOS = $^O eq 'MacOS';
77 @dl_require_symbols = (); # names of symbols we need
78 @dl_resolve_using = (); # names of files to link with
79 @dl_library_path = (); # path to look for files
80 #@dl_librefs = (); # things we have loaded
81 #@dl_modules = (); # Modules we have loaded
83 # This is a fix to support DLD's unfortunate desire to relink -lc
84 @dl_resolve_using = dl_findfile('-lc') if $dlsrc eq "dl_dld.xs";
86 # Initialise @dl_library_path with the 'standard' library path
87 # for this platform as determined by Configure
89 # push(@dl_library_path, split(' ', $Config::Config{'libpth'});
92 print OUT "push(\@dl_library_path, split(' ', ",
93 to_string($Config::Config{'libpth'}), "));\n";
97 # Add to @dl_library_path any extra directories we can gather
98 # from environment variables.
100 push(@dl_library_path, split(/,/, $ENV{LD_LIBRARY_PATH}))
101 if exists $ENV{LD_LIBRARY_PATH};
103 push(@dl_library_path, split(/:/, $ENV{$Config::Config{ldlibpthname}}))
104 if exists $Config::Config{ldlibpthname} &&
105 $Config::Config{ldlibpthname} ne '' &&
106 exists $ENV{$Config::Config{ldlibpthname}} ;;
107 push(@dl_library_path, split(/:/, $ENV{$Config::Config{ldlibpthname}}))
108 if exists $Config::Config{ldlibpthname} &&
109 $Config::Config{ldlibpthname} ne '' &&
110 exists $ENV{$Config::Config{ldlibpthname}} ;;
111 # E.g. HP-UX supports both its native SHLIB_PATH *and* LD_LIBRARY_PATH.
112 push(@dl_library_path, split(/:/, $ENV{LD_LIBRARY_PATH}))
113 if exists $ENV{LD_LIBRARY_PATH};
116 # No prizes for guessing why we don't say 'bootstrap DynaLoader;' here.
117 # NOTE: All dl_*.xs (including dl_none.xs) define a dl_error() XSUB
118 boot_DynaLoader('DynaLoader') if defined(&boot_DynaLoader) &&
122 print STDERR "DynaLoader.pm loaded (@INC, @dl_library_path)\n";
123 print STDERR "DynaLoader not linked into this perl\n"
124 unless defined(&boot_DynaLoader);
127 1; # End of main code
130 sub croak { require Carp; Carp::croak(@_) }
132 sub bootstrap_inherit {
134 local *isa = *{"$module\::ISA"};
135 local @isa = (@isa, 'DynaLoader');
136 # Cannot goto due to delocalization. Will report errors on a wrong line?
140 # The bootstrap function cannot be autoloaded (without complications)
141 # so we define it here:
144 # use local vars to enable $module.bs script to edit values
146 local($module) = $args[0];
151 Carp::confess("Usage: DynaLoader::bootstrap(module)");
154 # A common error on platforms which don't support dynamic loading.
155 # Since it's fatal and potentially confusing we give a detailed message.
156 croak("Can't load module $module, dynamic loading not available in this perl.\n".
157 " (You may need to build a new perl executable which either supports\n".
158 " dynamic loading or has the $module module statically linked into it.)\n")
159 unless defined(&dl_load_file);
161 my @modparts = split(/::/,$module);
162 my $modfname = $modparts[-1];
164 # Some systems have restrictions on files names for DLL's etc.
165 # mod2fname returns appropriate file base name (typically truncated)
166 # It may also edit @modparts if required.
167 $modfname = &mod2fname(\@modparts) if defined &mod2fname;
169 my $modpname = join(($Is_MacOS ? ':' : '/'),@modparts);
171 print STDERR "DynaLoader::bootstrap for $module ",
173 ? "(auto/$modpname/$modfname.$dl_dlext)\n" :
174 "(:auto:$modpname:$modfname.$dl_dlext)\n")
178 chop($_ = VMS::Filespec::unixpath($_)) if $Is_VMS;
182 $dir = "$_:auto:$modpname";
184 $dir = "$_/auto/$modpname";
186 next unless -d $dir; # skip over uninteresting directories
188 # check for common cases to avoid autoload of dl_findfile
189 my $try = $Is_MacOS ? "$dir:$modfname.$dl_dlext" : "$dir/$modfname.$dl_dlext";
190 last if $file = ($do_expand) ? dl_expandspec($try) : (-f $try && $try);
192 # no luck here, save dir for possible later dl_findfile search
195 # last resort, let dl_findfile have a go in all known locations
196 $file = dl_findfile(map("-L$_",@dirs,@INC), $modfname) unless $file;
198 croak("Can't locate loadable object for module $module in \@INC (\@INC contains: @INC)")
199 unless $file; # wording similar to error from 'require'
201 $file = uc($file) if $Is_VMS && $Config{d_vms_case_sensitive_symbols};
202 my $bootname = "boot_$module";
203 $bootname =~ s/\W/_/g;
204 @dl_require_symbols = ($bootname);
206 # Execute optional '.bootstrap' perl script for this module.
207 # The .bs file can be used to configure @dl_resolve_using etc to
208 # match the needs of the individual module on this architecture.
210 $bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library
211 if (-s $bs) { # only read file if it's not empty
212 print STDERR "BS: $bs ($^O, $dlsrc)\n" if $dl_debug;
214 warn "$bs: $@\n" if $@;
217 # Many dynamic extension loading problems will appear to come from
218 # this section of code: XYZ failed at line 123 of DynaLoader.pm.
219 # Often these errors are actually occurring in the initialisation
220 # C code of the extension XS file. Perl reports the error as being
221 # in this perl code simply because this was the last perl code
224 my $libref = dl_load_file($file, $module->dl_load_flags) or
225 croak("Can't load '$file' for module $module: ".dl_error());
227 push(@dl_librefs,$libref); # record loaded object
229 my @unresolved = dl_undef_symbols();
232 Carp::carp("Undefined symbols present after loading $file: @unresolved\n");
235 my $boot_symbol_ref = dl_find_symbol($libref, $bootname) or
236 croak("Can't find '$bootname' symbol in $file\n");
238 my $xs = dl_install_xsub("${module}::bootstrap", $boot_symbol_ref, $file);
240 push(@dl_modules, $module); # record loaded module
242 # See comment block above
247 #sub _check_file { # private utility to handle dl_expandspec vs -f tests
249 # return $file if (!$do_expand && -f $file); # the common case
250 # return $file if ( $do_expand && ($file=dl_expandspec($file)));
255 # Let autosplit and the autoloader deal with these functions:
260 # Read ext/DynaLoader/DynaLoader.doc for detailed information.
261 # This function does not automatically consider the architecture
262 # or the perl library auto directories.
264 my (@dirs, $dir); # which directories to search
265 my (@found); # full paths to real files we have found
268 print OUT ' my $dl_ext= ' . to_string($Config::Config{'dlext'}) .
269 "; # \$Config::Config{'dlext'} suffix for perl extensions\n";
270 print OUT ' my $dl_so = ' . to_string($Config::Config{'so'}) .
271 "; # \$Config::Config{'so'} suffix for shared libraries\n";
275 print STDERR "dl_findfile(@args)\n" if $dl_debug;
277 # accumulate directories but process files as they appear
278 arg: foreach(@args) {
279 # Special fast case: full filepath requires no search
280 if ($Is_VMS && m%[:>/\]]% && -f $_) {
281 push(@found,dl_expandspec(VMS::Filespec::vmsify($_)));
282 last arg unless wantarray;
288 last arg unless wantarray;
291 elsif (m:/: && -f $_ && !$do_expand) {
293 last arg unless wantarray;
297 # Deal with directories first:
298 # Using a -L prefix is the preferred option (faster and more robust)
299 if (m:^-L:) { s/^-L//; push(@dirs, $_); next; }
302 # Otherwise we try to try to spot directories by a heuristic
303 # (this is a more complicated issue than it first appears)
304 if (m/:/ && -d $_) { push(@dirs, $_); next; }
305 # Only files should get this far...
306 my(@names, $name); # what filenames to look for
309 foreach $dir (@dirs, @dl_library_path) {
311 $dir =~ s/^([^:]+)$/:$1/;
313 foreach $name (@names) {
314 my($file) = "$dir:$name";
315 print STDERR " checking in $dir for $name\n" if $dl_debug;
318 next arg; # no need to look any further
325 # Otherwise we try to try to spot directories by a heuristic
326 # (this is a more complicated issue than it first appears)
327 if (m:/: && -d $_) { push(@dirs, $_); next; }
329 # VMS: we may be using native VMS directry syntax instead of
330 # Unix emulation, so check this as well
331 if ($Is_VMS && /[:>\]]/ && -d $_) { push(@dirs, $_); next; }
333 # Only files should get this far...
334 my(@names, $name); # what filenames to look for
335 if (m:-l: ) { # convert -lname to appropriate library name
337 push(@names,"lib$_.$dl_so");
338 push(@names,"lib$_.a");
339 } else { # Umm, a bare name. Try various alternatives:
340 # these should be ordered with the most likely first
341 push(@names,"$_.$dl_ext") unless m/\.$dl_ext$/o;
342 push(@names,"$_.$dl_so") unless m/\.$dl_so$/o;
343 push(@names,"lib$_.$dl_so") unless m:/:;
344 push(@names,"$_.a") if !m/\.a$/ and $dlsrc eq "dl_dld.xs";
347 foreach $dir (@dirs, @dl_library_path) {
349 chop($dir = VMS::Filespec::unixpath($dir)) if $Is_VMS;
350 foreach $name (@names) {
351 my($file) = "$dir/$name";
352 print STDERR " checking in $dir for $name\n" if $dl_debug;
353 $file = ($do_expand) ? dl_expandspec($file) : (-f $file && $file);
354 #$file = _check_file($file);
357 next arg; # no need to look any further
364 print STDERR " dl_findfile ignored non-existent directory: $_\n" unless -d $_;
366 print STDERR "dl_findfile found: @found\n";
368 return $found[0] unless wantarray;
375 # Optional function invoked if DynaLoader.pm sets $do_expand.
376 # Most systems do not require or use this function.
377 # Some systems may implement it in the dl_*.xs file in which case
378 # this autoload version will not be called but is harmless.
380 # This function is designed to deal with systems which treat some
381 # 'filenames' in a special way. For example VMS 'Logical Names'
382 # (something like unix environment variables - but different).
383 # This function should recognise such names and expand them into
385 # Must return undef if $spec is invalid or file does not exist.
387 my $file = $spec; # default output to input
389 if ($Is_VMS) { # dl_expandspec should be defined in dl_vms.xs
391 Carp::croak("dl_expandspec: should be defined in XS file!\n");
393 return undef unless -f $file;
395 print STDERR "dl_expandspec($spec) => $file\n" if $dl_debug;
399 sub dl_find_symbol_anywhere
403 foreach $libref (@dl_librefs) {
404 my $symref = dl_find_symbol($libref,$sym);
405 return $symref if $symref;
412 DynaLoader - Dynamically load C libraries into Perl code
414 dl_error(), dl_findfile(), dl_expandspec(), dl_load_file(), dl_unload_file(), dl_find_symbol(), dl_find_symbol_anywhere(), dl_undef_symbols(), dl_install_xsub(), dl_load_flags(), bootstrap() - routines used by DynaLoader modules
420 @ISA = qw(... DynaLoader ...);
421 bootstrap YourPackage;
423 # optional method for 'global' loading
424 sub dl_load_flags { 0x01 }
429 This document defines a standard generic interface to the dynamic
430 linking mechanisms available on many platforms. Its primary purpose is
431 to implement automatic dynamic loading of Perl modules.
433 This document serves as both a specification for anyone wishing to
434 implement the DynaLoader for a new platform and as a guide for
435 anyone wishing to use the DynaLoader directly in an application.
437 The DynaLoader is designed to be a very simple high-level
438 interface that is sufficiently general to cover the requirements
439 of SunOS, HP-UX, NeXT, Linux, VMS and other platforms.
441 It is also hoped that the interface will cover the needs of OS/2, NT
442 etc and also allow pseudo-dynamic linking (using C<ld -A> at runtime).
444 It must be stressed that the DynaLoader, by itself, is practically
445 useless for accessing non-Perl libraries because it provides almost no
446 Perl-to-C 'glue'. There is, for example, no mechanism for calling a C
447 library function or supplying arguments. A C::DynaLib module
448 is available from CPAN sites which performs that function for some
451 DynaLoader Interface Summary
460 bootstrap($modulename) Perl
461 @filepaths = dl_findfile(@names) Perl
462 $flags = $modulename->dl_load_flags Perl
463 $symref = dl_find_symbol_anywhere($symbol) Perl
465 $libref = dl_load_file($filename, $flags) C
466 $status = dl_unload_file($libref) C
467 $symref = dl_find_symbol($libref, $symbol) C
468 @symbols = dl_undef_symbols() C
469 dl_install_xsub($name, $symref [, $filename]) C
470 $message = dl_error C
474 =item @dl_library_path
476 The standard/default list of directories in which dl_findfile() will
477 search for libraries etc. Directories are searched in order:
478 $dl_library_path[0], [1], ... etc
480 @dl_library_path is initialised to hold the list of 'normal' directories
481 (F</usr/lib>, etc) determined by B<Configure> (C<$Config{'libpth'}>). This should
482 ensure portability across a wide range of platforms.
484 @dl_library_path should also be initialised with any other directories
485 that can be determined from the environment at runtime (such as
486 LD_LIBRARY_PATH for SunOS).
488 After initialisation @dl_library_path can be manipulated by an
489 application using push and unshift before calling dl_findfile().
490 Unshift can be used to add directories to the front of the search order
491 either to save search time or to override libraries with the same name
492 in the 'normal' directories.
494 The load function that dl_load_file() calls may require an absolute
495 pathname. The dl_findfile() function and @dl_library_path can be
496 used to search for and return the absolute pathname for the
497 library/object that you wish to load.
499 =item @dl_resolve_using
501 A list of additional libraries or other shared objects which can be
502 used to resolve any undefined symbols that might be generated by a
503 later call to load_file().
505 This is only required on some platforms which do not handle dependent
506 libraries automatically. For example the Socket Perl extension
507 library (F<auto/Socket/Socket.so>) contains references to many socket
508 functions which need to be resolved when it's loaded. Most platforms
509 will automatically know where to find the 'dependent' library (e.g.,
510 F</usr/lib/libsocket.so>). A few platforms need to be told the
511 location of the dependent library explicitly. Use @dl_resolve_using
516 @dl_resolve_using = dl_findfile('-lsocket');
518 =item @dl_require_symbols
520 A list of one or more symbol names that are in the library/object file
521 to be dynamically loaded. This is only required on some platforms.
525 An array of the handles returned by successful calls to dl_load_file(),
526 made by bootstrap, in the order in which they were loaded.
527 Can be used with dl_find_symbol() to look for a symbol in any of
532 An array of module (package) names that have been bootstrap'ed.
538 $message = dl_error();
540 Error message text from the last failed DynaLoader function. Note
541 that, similar to errno in unix, a successful function call does not
544 Implementations should detect the error as soon as it occurs in any of
545 the other functions and save the corresponding message for later
546 retrieval. This will avoid problems on some platforms (such as SunOS)
547 where the error message is very temporary (e.g., dlerror()).
551 Internal debugging messages are enabled when $dl_debug is set true.
552 Currently setting $dl_debug only affects the Perl side of the
553 DynaLoader. These messages should help an application developer to
554 resolve any DynaLoader usage problems.
556 $dl_debug is set to C<$ENV{'PERL_DL_DEBUG'}> if defined.
558 For the DynaLoader developer/porter there is a similar debugging
559 variable added to the C code (see dlutils.c) and enabled if Perl was
560 built with the B<-DDEBUGGING> flag. This can also be set via the
561 PERL_DL_DEBUG environment variable. Set to 1 for minimal information or
568 @filepaths = dl_findfile(@names)
570 Determine the full paths (including file suffix) of one or more
571 loadable files given their generic names and optionally one or more
572 directories. Searches directories in @dl_library_path by default and
573 returns an empty list if no files were found.
575 Names can be specified in a variety of platform independent forms. Any
576 names in the form B<-lname> are converted into F<libname.*>, where F<.*> is
577 an appropriate suffix for the platform.
579 If a name does not already have a suitable prefix and/or suffix then
580 the corresponding file will be searched for by trying combinations of
581 prefix and suffix appropriate to the platform: "$name.o", "lib$name.*"
584 If any directories are included in @names they are searched before
585 @dl_library_path. Directories may be specified as B<-Ldir>. Any other
586 names are treated as filenames to be searched for.
588 Using arguments of the form C<-Ldir> and C<-lname> is recommended.
592 @dl_resolve_using = dl_findfile(qw(-L/usr/5lib -lposix));
595 =item dl_expandspec()
599 $filepath = dl_expandspec($spec)
601 Some unusual systems, such as VMS, require special filename handling in
602 order to deal with symbolic names for files (i.e., VMS's Logical Names).
604 To support these systems a dl_expandspec() function can be implemented
605 either in the F<dl_*.xs> file or code can be added to the autoloadable
606 dl_expandspec() function in F<DynaLoader.pm>. See F<DynaLoader.pm> for
613 $libref = dl_load_file($filename, $flags)
615 Dynamically load $filename, which must be the path to a shared object
616 or library. An opaque 'library reference' is returned as a handle for
617 the loaded object. Returns undef on error.
619 The $flags argument to alters dl_load_file behaviour.
622 0x01 make symbols available for linking later dl_load_file's.
623 (only known to work on Solaris 2 using dlopen(RTLD_GLOBAL))
624 (ignored under VMS; this is a normal part of image linking)
626 (On systems that provide a handle for the loaded object such as SunOS
627 and HPUX, $libref will be that handle. On other systems $libref will
628 typically be $filename or a pointer to a buffer containing $filename.
629 The application should not examine or alter $libref in any way.)
631 This is the function that does the real work. It should use the
632 current values of @dl_require_symbols and @dl_resolve_using if required.
634 SunOS: dlopen($filename)
635 HP-UX: shl_load($filename)
636 Linux: dld_create_reference(@dl_require_symbols); dld_link($filename)
637 NeXT: rld_load($filename, @dl_resolve_using)
638 VMS: lib$find_image_symbol($filename,$dl_require_symbols[0])
640 (The dlopen() function is also used by Solaris and some versions of
641 Linux, and is a common choice when providing a "wrapper" on other
642 mechanisms as is done in the OS/2 port.)
644 =item dl_unload_file()
648 $status = dl_unload_file($libref)
650 Dynamically unload $libref, which must be an opaque 'library reference' as
651 returned from dl_load_file. Returns one on success and zero on failure.
653 This function is optional and may not necessarily be provided on all platforms.
654 If it is defined, it is called automatically when the interpreter exits for
655 every shared object or library loaded by DynaLoader::bootstrap. All such
656 library references are stored in @dl_librefs by DynaLoader::Bootstrap as it
657 loads the libraries. The files are unloaded in last-in, first-out order.
659 This unloading is usually necessary when embedding a shared-object perl (e.g.
660 one configured with -Duseshrplib) within a larger application, and the perl
661 interpreter is created and destroyed several times within the lifetime of the
662 application. In this case it is possible that the system dynamic linker will
663 unload and then subsequently reload the shared libperl without relocating any
664 references to it from any files DynaLoaded by the previous incarnation of the
665 interpreter. As a result, any shared objects opened by DynaLoader may point to
666 a now invalid 'ghost' of the libperl shared object, causing apparently random
667 memory corruption and crashes. This behaviour is most commonly seen when using
668 Apache and mod_perl built with the APXS mechanism.
670 SunOS: dlclose($libref)
676 (The dlclose() function is also used by Solaris and some versions of
677 Linux, and is a common choice when providing a "wrapper" on other
678 mechanisms as is done in the OS/2 port.)
684 $flags = dl_loadflags $modulename;
686 Designed to be a method call, and to be overridden by a derived class
687 (i.e. a class which has DynaLoader in its @ISA). The definition in
688 DynaLoader itself returns 0, which produces standard behavior from
691 =item dl_find_symbol()
695 $symref = dl_find_symbol($libref, $symbol)
697 Return the address of the symbol $symbol or C<undef> if not found. If the
698 target system has separate functions to search for symbols of different
699 types then dl_find_symbol() should search for function symbols first and
702 The exact manner in which the address is returned in $symref is not
703 currently defined. The only initial requirement is that $symref can
704 be passed to, and understood by, dl_install_xsub().
706 SunOS: dlsym($libref, $symbol)
707 HP-UX: shl_findsym($libref, $symbol)
708 Linux: dld_get_func($symbol) and/or dld_get_symbol($symbol)
709 NeXT: rld_lookup("_$symbol")
710 VMS: lib$find_image_symbol($libref,$symbol)
713 =item dl_find_symbol_anywhere()
717 $symref = dl_find_symbol_anywhere($symbol)
719 Applies dl_find_symbol() to the members of @dl_librefs and returns
720 the first match found.
722 =item dl_undef_symbols()
726 @symbols = dl_undef_symbols()
728 Return a list of symbol names which remain undefined after load_file().
729 Returns C<()> if not known. Don't worry if your platform does not provide
730 a mechanism for this. Most do not need it and hence do not provide it,
731 they just return an empty list.
734 =item dl_install_xsub()
738 dl_install_xsub($perl_name, $symref [, $filename])
740 Create a new Perl external subroutine named $perl_name using $symref as
741 a pointer to the function which implements the routine. This is simply
742 a direct call to newXSUB(). Returns a reference to the installed
745 The $filename parameter is used by Perl to identify the source file for
746 the function if required by die(), caller() or the debugger. If
747 $filename is not defined then "DynaLoader" will be used.
756 This is the normal entry point for automatic dynamic loading in Perl.
758 It performs the following actions:
764 locates an auto/$module directory by searching @INC
768 uses dl_findfile() to determine the filename to load
772 sets @dl_require_symbols to C<("boot_$module")>
776 executes an F<auto/$module/$module.bs> file if it exists
777 (typically used to add to @dl_resolve_using any files which
778 are required to load the module on the current platform)
782 calls dl_load_flags() to determine how to load the file.
786 calls dl_load_file() to load the file
790 calls dl_undef_symbols() and warns if any symbols are undefined
794 calls dl_find_symbol() for "boot_$module"
798 calls dl_install_xsub() to install it as "${module}::bootstrap"
802 calls &{"${module}::bootstrap"} to bootstrap the module (actually
803 it uses the function reference returned by dl_install_xsub for speed)
812 Tim Bunce, 11 August 1994.
814 This interface is based on the work and comments of (in no particular
815 order): Larry Wall, Robert Sanders, Dean Roehrich, Jeff Okamoto, Anno
816 Siegel, Thomas Neumann, Paul Marquess, Charles Bailey, myself and others.
818 Larry Wall designed the elegant inherited bootstrap mechanism and
819 implemented the first Perl 5 dynamic loader using it.
821 Solaris global loading added by Nick Ing-Simmons with design/coding
822 assistance from Tim Bunce, January 1996.