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03c9e98c
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1
2use Config;
3
4sub to_string {
5 my ($value) = @_;
6 $value =~ s/\\/\\\\'/g;
7 $value =~ s/'/\\'/g;
8 return "'$value'";
9}
10
11unlink "DynaLoader.pm" if -f "DynaLoader.pm";
12open OUT, ">DynaLoader.pm" or die $!;
13print OUT <<'EOT';
14
15# Generated from DynaLoader.pm.PL (resolved %Config::Config values)
16
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17package DynaLoader;
18
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19# And Gandalf said: 'Many folk like to know beforehand what is to
20# be set on the table; but those who have laboured to prepare the
21# feast like to keep their secret; for wonder makes the words of
22# praise louder.'
23
24# (Quote from Tolkien sugested by Anno Siegel.)
25#
26# See pod text at end of file for documentation.
27# See also ext/DynaLoader/README in source tree for other information.
28#
29# Tim.Bunce@ig.co.uk, August 1994
30
fb73857a 31$VERSION = $VERSION = "1.03"; # avoid typo warning
dc848c6f 32
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33require AutoLoader;
34*AUTOLOAD = \&AutoLoader::AUTOLOAD;
8e07c86e 35
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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.
41require Carp if $] < 5.00450;
42
43
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44# enable debug/trace messages from DynaLoader perl code
45$dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug;
46
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47#
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))
f86702cc 51# (ignored under VMS; effect is built-in to image linking)
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52#
53# This is called as a class method $module->dl_load_flags. The
54# definition here will be inherited and result on "default" loading
55# behaviour unless a sub-class of DynaLoader defines its own version.
56#
57
58sub dl_load_flags { 0x00 }
59
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60# ($dl_dlext, $dlsrc)
61# = @Config::Config{'dlext', 'dlsrc'};
62EOT
63
64print OUT " (\$dl_dlext, \$dlsrc) = (",
65 to_string($Config::Config{'dlext'}), ",",
66 to_string($Config::Config{'dlsrc'}), ")\n;" ;
ff7f3c60 67
03c9e98c 68print OUT <<'EOT';
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69
70# Some systems need special handling to expand file specifications
71# (VMS support by Charles Bailey <bailey@HMIVAX.HUMGEN.UPENN.EDU>)
72# See dl_expandspec() for more details. Should be harmless but
73# inefficient to define on systems that don't need it.
d404d5bf 74$do_expand = $Is_VMS = $^O eq 'VMS';
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75
76@dl_require_symbols = (); # names of symbols we need
77@dl_resolve_using = (); # names of files to link with
78@dl_library_path = (); # path to look for files
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79@dl_librefs = (); # things we have loaded
80@dl_modules = (); # Modules we have loaded
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81
82# This is a fix to support DLD's unfortunate desire to relink -lc
83@dl_resolve_using = dl_findfile('-lc') if $dlsrc eq "dl_dld.xs";
84
85# Initialise @dl_library_path with the 'standard' library path
86# for this platform as determined by Configure
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87
88# push(@dl_library_path, split(' ', $Config::Config{'libpth'});
89EOT
90
91print OUT "push(\@dl_library_path, split(' ', ",
92 to_string($Config::Config{'libpth'}), "));\n";
93
94print OUT <<'EOT';
8e07c86e 95
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96# Add to @dl_library_path any extra directories we can gather
97# from environment variables.
98push(@dl_library_path, split(/:/, $ENV{$Config::Config{ldlibpthname}}))
99 if exists $Config::Config{ldlibpthname} &&
100 $Config::Config{ldlibpthname} ne '' &&
101 exists $ENV{$Config::Config{ldlibpthname}} ;;
102# E.g. HP-UX supports both its native SHLIB_PATH *and* LD_LIBRARY_PATH.
8e07c86e 103push(@dl_library_path, split(/:/, $ENV{LD_LIBRARY_PATH}))
5cf1d1f1 104 if exists $ENV{LD_LIBRARY_PATH};
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105
106# No prizes for guessing why we don't say 'bootstrap DynaLoader;' here.
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107boot_DynaLoader('DynaLoader') if defined(&boot_DynaLoader) &&
108 !defined(&dl_load_file);
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109
110
111if ($dl_debug) {
112 print STDERR "DynaLoader.pm loaded (@INC, @dl_library_path)\n";
113 print STDERR "DynaLoader not linked into this perl\n"
114 unless defined(&boot_DynaLoader);
115}
116
1171; # End of main code
118
119
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120sub croak { require Carp; Carp::croak(@_) }
121
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122# The bootstrap function cannot be autoloaded (without complications)
123# so we define it here:
124
125sub bootstrap {
126 # use local vars to enable $module.bs script to edit values
127 local(@args) = @_;
128 local($module) = $args[0];
129 local(@dirs, $file);
130
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131 unless ($module) {
132 require Carp;
133 Carp::confess("Usage: DynaLoader::bootstrap(module)");
134 }
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135
136 # A common error on platforms which don't support dynamic loading.
137 # Since it's fatal and potentially confusing we give a detailed message.
fb73857a 138 croak("Can't load module $module, dynamic loading not available in this perl.\n".
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139 " (You may need to build a new perl executable which either supports\n".
140 " dynamic loading or has the $module module statically linked into it.)\n")
141 unless defined(&dl_load_file);
142
143 my @modparts = split(/::/,$module);
144 my $modfname = $modparts[-1];
145
146 # Some systems have restrictions on files names for DLL's etc.
147 # mod2fname returns appropriate file base name (typically truncated)
148 # It may also edit @modparts if required.
149 $modfname = &mod2fname(\@modparts) if defined &mod2fname;
150
151 my $modpname = join('/',@modparts);
152
153 print STDERR "DynaLoader::bootstrap for $module ",
154 "(auto/$modpname/$modfname.$dl_dlext)\n" if $dl_debug;
155
156 foreach (@INC) {
54d6a3b3 157 chop($_ = VMS::Filespec::unixpath($_)) if $Is_VMS;
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158 my $dir = "$_/auto/$modpname";
159 next unless -d $dir; # skip over uninteresting directories
160
161 # check for common cases to avoid autoload of dl_findfile
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162 my $try = "$dir/$modfname.$dl_dlext";
163 last if $file = ($do_expand) ? dl_expandspec($try) : (-f $try && $try);
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164
165 # no luck here, save dir for possible later dl_findfile search
fb73857a 166 push @dirs, $dir;
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167 }
168 # last resort, let dl_findfile have a go in all known locations
fb73857a 169 $file = dl_findfile(map("-L$_",@dirs,@INC), $modfname) unless $file;
8e07c86e 170
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171 croak("Can't locate loadable object for module $module in \@INC (\@INC contains: @INC)")
172 unless $file; # wording similar to error from 'require'
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173
174 my $bootname = "boot_$module";
175 $bootname =~ s/\W/_/g;
176 @dl_require_symbols = ($bootname);
177
178 # Execute optional '.bootstrap' perl script for this module.
179 # The .bs file can be used to configure @dl_resolve_using etc to
180 # match the needs of the individual module on this architecture.
181 my $bs = $file;
3f45a6dd 182 $bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library
8e07c86e 183 if (-s $bs) { # only read file if it's not empty
d404d5bf 184 print STDERR "BS: $bs ($^O, $dlsrc)\n" if $dl_debug;
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185 eval { do $bs; };
186 warn "$bs: $@\n" if $@;
187 }
188
189 # Many dynamic extension loading problems will appear to come from
190 # this section of code: XYZ failed at line 123 of DynaLoader.pm.
191 # Often these errors are actually occurring in the initialisation
192 # C code of the extension XS file. Perl reports the error as being
193 # in this perl code simply because this was the last perl code
194 # it executed.
195
ff7f3c60 196 my $libref = dl_load_file($file, $module->dl_load_flags) or
549a6b10 197 croak("Can't load '$file' for module $module: ".dl_error());
8e07c86e 198
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199 push(@dl_librefs,$libref); # record loaded object
200
8e07c86e 201 my @unresolved = dl_undef_symbols();
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202 if (@unresolved) {
203 require Carp;
204 Carp::carp("Undefined symbols present after loading $file: @unresolved\n");
205 }
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206
207 my $boot_symbol_ref = dl_find_symbol($libref, $bootname) or
fb73857a 208 croak("Can't find '$bootname' symbol in $file\n");
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209
210 my $xs = dl_install_xsub("${module}::bootstrap", $boot_symbol_ref, $file);
211
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212 push(@dl_modules, $module); # record loaded module
213
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214 # See comment block above
215 &$xs(@args);
216}
217
218
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219#sub _check_file { # private utility to handle dl_expandspec vs -f tests
220# my($file) = @_;
221# return $file if (!$do_expand && -f $file); # the common case
222# return $file if ( $do_expand && ($file=dl_expandspec($file)));
223# return undef;
224#}
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225
226
227# Let autosplit and the autoloader deal with these functions:
228__END__
229
230
231sub dl_findfile {
232 # Read ext/DynaLoader/DynaLoader.doc for detailed information.
233 # This function does not automatically consider the architecture
234 # or the perl library auto directories.
235 my (@args) = @_;
236 my (@dirs, $dir); # which directories to search
237 my (@found); # full paths to real files we have found
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238EOT
239
240print OUT ' my $dl_ext= ' . to_string($Config::Config{'dlext'}) .
241 "; # \$Config::Config{'dlext'} suffix for perl extensions\n";
242print OUT ' my $dl_so = ' . to_string($Config::Config{'so'}) .
243 "; # \$Config::Config{'so'} suffix for shared libraries\n";
244
245print OUT <<'EOT';
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246
247 print STDERR "dl_findfile(@args)\n" if $dl_debug;
248
249 # accumulate directories but process files as they appear
250 arg: foreach(@args) {
251 # Special fast case: full filepath requires no search
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252 if ($Is_VMS && m%[:>/\]]% && -f $_) {
253 push(@found,dl_expandspec(VMS::Filespec::vmsify($_)));
254 last arg unless wantarray;
255 next;
256 }
257 elsif (m:/: && -f $_ && !$do_expand) {
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258 push(@found,$_);
259 last arg unless wantarray;
260 next;
261 }
262
263 # Deal with directories first:
264 # Using a -L prefix is the preferred option (faster and more robust)
265 if (m:^-L:) { s/^-L//; push(@dirs, $_); next; }
266
267 # Otherwise we try to try to spot directories by a heuristic
268 # (this is a more complicated issue than it first appears)
269 if (m:/: && -d $_) { push(@dirs, $_); next; }
270
271 # VMS: we may be using native VMS directry syntax instead of
272 # Unix emulation, so check this as well
54d6a3b3 273 if ($Is_VMS && /[:>\]]/ && -d $_) { push(@dirs, $_); next; }
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274
275 # Only files should get this far...
276 my(@names, $name); # what filenames to look for
277 if (m:-l: ) { # convert -lname to appropriate library name
278 s/-l//;
279 push(@names,"lib$_.$dl_so");
280 push(@names,"lib$_.a");
281 } else { # Umm, a bare name. Try various alternatives:
282 # these should be ordered with the most likely first
d404d5bf 283 push(@names,"$_.$dl_ext") unless m/\.$dl_ext$/o;
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284 push(@names,"$_.$dl_so") unless m/\.$dl_so$/o;
285 push(@names,"lib$_.$dl_so") unless m:/:;
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286 push(@names,"$_.a") if !m/\.a$/ and $dlsrc eq "dl_dld.xs";
287 push(@names, $_);
288 }
289 foreach $dir (@dirs, @dl_library_path) {
290 next unless -d $dir;
54d6a3b3 291 chop($dir = VMS::Filespec::unixpath($dir)) if $Is_VMS;
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292 foreach $name (@names) {
293 my($file) = "$dir/$name";
294 print STDERR " checking in $dir for $name\n" if $dl_debug;
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295 $file = ($do_expand) ? dl_expandspec($file) : (-f $file && $file);
296 #$file = _check_file($file);
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297 if ($file) {
298 push(@found, $file);
299 next arg; # no need to look any further
300 }
301 }
302 }
303 }
304 if ($dl_debug) {
305 foreach(@dirs) {
306 print STDERR " dl_findfile ignored non-existent directory: $_\n" unless -d $_;
307 }
308 print STDERR "dl_findfile found: @found\n";
309 }
310 return $found[0] unless wantarray;
311 @found;
312}
313
314
315sub dl_expandspec {
316 my($spec) = @_;
317 # Optional function invoked if DynaLoader.pm sets $do_expand.
318 # Most systems do not require or use this function.
319 # Some systems may implement it in the dl_*.xs file in which case
320 # this autoload version will not be called but is harmless.
321
322 # This function is designed to deal with systems which treat some
323 # 'filenames' in a special way. For example VMS 'Logical Names'
324 # (something like unix environment variables - but different).
325 # This function should recognise such names and expand them into
326 # full file paths.
327 # Must return undef if $spec is invalid or file does not exist.
328
329 my $file = $spec; # default output to input
330
d404d5bf 331 if ($Is_VMS) { # dl_expandspec should be defined in dl_vms.xs
fb73857a 332 require Carp;
4633a7c4 333 Carp::croak("dl_expandspec: should be defined in XS file!\n");
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334 } else {
335 return undef unless -f $file;
336 }
337 print STDERR "dl_expandspec($spec) => $file\n" if $dl_debug;
338 $file;
339}
340
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341sub dl_find_symbol_anywhere
342{
343 my $sym = shift;
344 my $libref;
345 foreach $libref (@dl_librefs) {
346 my $symref = dl_find_symbol($libref,$sym);
347 return $symref if $symref;
348 }
349 return undef;
350}
8e07c86e 351
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352=head1 NAME
353
354DynaLoader - Dynamically load C libraries into Perl code
355
ff7f3c60 356dl_error(), dl_findfile(), dl_expandspec(), dl_load_file(), dl_find_symbol(), dl_find_symbol_anywhere(), dl_undef_symbols(), dl_install_xsub(), dl_load_flags(), bootstrap() - routines used by DynaLoader modules
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357
358=head1 SYNOPSIS
359
8e07c86e 360 package YourPackage;
3b35bae3 361 require DynaLoader;
c2960299 362 @ISA = qw(... DynaLoader ...);
8e07c86e 363 bootstrap YourPackage;
3b35bae3 364
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365 # optional method for 'global' loading
366 sub dl_load_flags { 0x01 }
367
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368
369=head1 DESCRIPTION
370
c2960299 371This document defines a standard generic interface to the dynamic
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372linking mechanisms available on many platforms. Its primary purpose is
373to implement automatic dynamic loading of Perl modules.
374
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375This document serves as both a specification for anyone wishing to
376implement the DynaLoader for a new platform and as a guide for
377anyone wishing to use the DynaLoader directly in an application.
378
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379The DynaLoader is designed to be a very simple high-level
380interface that is sufficiently general to cover the requirements
381of SunOS, HP-UX, NeXT, Linux, VMS and other platforms.
382
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383It is also hoped that the interface will cover the needs of OS/2, NT
384etc and also allow pseudo-dynamic linking (using C<ld -A> at runtime).
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385
386It must be stressed that the DynaLoader, by itself, is practically
387useless for accessing non-Perl libraries because it provides almost no
388Perl-to-C 'glue'. There is, for example, no mechanism for calling a C
03c9e98c 389library function or supplying arguments. A C::DynaLib module
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390is available from CPAN sites which performs that function for some
391common system types.
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392
393DynaLoader Interface Summary
394
395 @dl_library_path
396 @dl_resolve_using
397 @dl_require_symbols
398 $dl_debug
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399 @dl_librefs
400 @dl_modules
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401 Implemented in:
402 bootstrap($modulename) Perl
403 @filepaths = dl_findfile(@names) Perl
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404 $flags = $modulename->dl_load_flags Perl
405 $symref = dl_find_symbol_anywhere($symbol) Perl
3b35bae3 406
ff7f3c60 407 $libref = dl_load_file($filename, $flags) C
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408 $symref = dl_find_symbol($libref, $symbol) C
409 @symbols = dl_undef_symbols() C
410 dl_install_xsub($name, $symref [, $filename]) C
411 $message = dl_error C
412
413=over 4
414
415=item @dl_library_path
416
417The standard/default list of directories in which dl_findfile() will
418search for libraries etc. Directories are searched in order:
419$dl_library_path[0], [1], ... etc
420
421@dl_library_path is initialised to hold the list of 'normal' directories
422(F</usr/lib>, etc) determined by B<Configure> (C<$Config{'libpth'}>). This should
423ensure portability across a wide range of platforms.
424
425@dl_library_path should also be initialised with any other directories
426that can be determined from the environment at runtime (such as
427LD_LIBRARY_PATH for SunOS).
428
429After initialisation @dl_library_path can be manipulated by an
430application using push and unshift before calling dl_findfile().
431Unshift can be used to add directories to the front of the search order
432either to save search time or to override libraries with the same name
433in the 'normal' directories.
434
435The load function that dl_load_file() calls may require an absolute
436pathname. The dl_findfile() function and @dl_library_path can be
437used to search for and return the absolute pathname for the
438library/object that you wish to load.
439
440=item @dl_resolve_using
441
442A list of additional libraries or other shared objects which can be
443used to resolve any undefined symbols that might be generated by a
444later call to load_file().
445
446This is only required on some platforms which do not handle dependent
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447libraries automatically. For example the Socket Perl extension
448library (F<auto/Socket/Socket.so>) contains references to many socket
449functions which need to be resolved when it's loaded. Most platforms
450will automatically know where to find the 'dependent' library (e.g.,
451F</usr/lib/libsocket.so>). A few platforms need to be told the
452location of the dependent library explicitly. Use @dl_resolve_using
453for this.
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454
455Example usage:
456
457 @dl_resolve_using = dl_findfile('-lsocket');
458
459=item @dl_require_symbols
460
461A list of one or more symbol names that are in the library/object file
462to be dynamically loaded. This is only required on some platforms.
463
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464=item @dl_librefs
465
466An array of the handles returned by successful calls to dl_load_file(),
467made by bootstrap, in the order in which they were loaded.
468Can be used with dl_find_symbol() to look for a symbol in any of
469the loaded files.
470
471=item @dl_modules
472
473An array of module (package) names that have been bootstrap'ed.
474
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475=item dl_error()
476
477Syntax:
478
479 $message = dl_error();
480
481Error message text from the last failed DynaLoader function. Note
482that, similar to errno in unix, a successful function call does not
483reset this message.
484
485Implementations should detect the error as soon as it occurs in any of
486the other functions and save the corresponding message for later
487retrieval. This will avoid problems on some platforms (such as SunOS)
488where the error message is very temporary (e.g., dlerror()).
489
490=item $dl_debug
491
492Internal debugging messages are enabled when $dl_debug is set true.
493Currently setting $dl_debug only affects the Perl side of the
494DynaLoader. These messages should help an application developer to
495resolve any DynaLoader usage problems.
496
497$dl_debug is set to C<$ENV{'PERL_DL_DEBUG'}> if defined.
498
499For the DynaLoader developer/porter there is a similar debugging
500variable added to the C code (see dlutils.c) and enabled if Perl was
501built with the B<-DDEBUGGING> flag. This can also be set via the
502PERL_DL_DEBUG environment variable. Set to 1 for minimal information or
503higher for more.
504
505=item dl_findfile()
506
507Syntax:
508
509 @filepaths = dl_findfile(@names)
510
511Determine the full paths (including file suffix) of one or more
512loadable files given their generic names and optionally one or more
513directories. Searches directories in @dl_library_path by default and
514returns an empty list if no files were found.
515
516Names can be specified in a variety of platform independent forms. Any
517names in the form B<-lname> are converted into F<libname.*>, where F<.*> is
518an appropriate suffix for the platform.
519
520If a name does not already have a suitable prefix and/or suffix then
521the corresponding file will be searched for by trying combinations of
522prefix and suffix appropriate to the platform: "$name.o", "lib$name.*"
523and "$name".
524
525If any directories are included in @names they are searched before
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526@dl_library_path. Directories may be specified as B<-Ldir>. Any other
527names are treated as filenames to be searched for.
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528
529Using arguments of the form C<-Ldir> and C<-lname> is recommended.
530
531Example:
532
533 @dl_resolve_using = dl_findfile(qw(-L/usr/5lib -lposix));
534
535
536=item dl_expandspec()
537
538Syntax:
539
540 $filepath = dl_expandspec($spec)
541
542Some unusual systems, such as VMS, require special filename handling in
543order to deal with symbolic names for files (i.e., VMS's Logical Names).
544
545To support these systems a dl_expandspec() function can be implemented
546either in the F<dl_*.xs> file or code can be added to the autoloadable
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547dl_expandspec() function in F<DynaLoader.pm>. See F<DynaLoader.pm> for
548more information.
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549
550=item dl_load_file()
551
552Syntax:
553
ff7f3c60 554 $libref = dl_load_file($filename, $flags)
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555
556Dynamically load $filename, which must be the path to a shared object
557or library. An opaque 'library reference' is returned as a handle for
558the loaded object. Returns undef on error.
559
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560The $flags argument to alters dl_load_file behaviour.
561Assigned bits:
562
563 0x01 make symbols available for linking later dl_load_file's.
564 (only known to work on Solaris 2 using dlopen(RTLD_GLOBAL))
f86702cc 565 (ignored under VMS; this is a normal part of image linking)
ff7f3c60 566
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567(On systems that provide a handle for the loaded object such as SunOS
568and HPUX, $libref will be that handle. On other systems $libref will
569typically be $filename or a pointer to a buffer containing $filename.
570The application should not examine or alter $libref in any way.)
571
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572This is the function that does the real work. It should use the
573current values of @dl_require_symbols and @dl_resolve_using if required.
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574
575 SunOS: dlopen($filename)
576 HP-UX: shl_load($filename)
577 Linux: dld_create_reference(@dl_require_symbols); dld_link($filename)
578 NeXT: rld_load($filename, @dl_resolve_using)
579 VMS: lib$find_image_symbol($filename,$dl_require_symbols[0])
580
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581(The dlopen() function is also used by Solaris and some versions of
582Linux, and is a common choice when providing a "wrapper" on other
583mechanisms as is done in the OS/2 port.)
584
585=item dl_loadflags()
586
587Syntax:
588
589 $flags = dl_loadflags $modulename;
590
591Designed to be a method call, and to be overridden by a derived class
592(i.e. a class which has DynaLoader in its @ISA). The definition in
593DynaLoader itself returns 0, which produces standard behavior from
594dl_load_file().
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595
596=item dl_find_symbol()
597
598Syntax:
599
600 $symref = dl_find_symbol($libref, $symbol)
601
602Return the address of the symbol $symbol or C<undef> if not found. If the
603target system has separate functions to search for symbols of different
604types then dl_find_symbol() should search for function symbols first and
605then other types.
606
607The exact manner in which the address is returned in $symref is not
608currently defined. The only initial requirement is that $symref can
609be passed to, and understood by, dl_install_xsub().
610
611 SunOS: dlsym($libref, $symbol)
612 HP-UX: shl_findsym($libref, $symbol)
613 Linux: dld_get_func($symbol) and/or dld_get_symbol($symbol)
614 NeXT: rld_lookup("_$symbol")
615 VMS: lib$find_image_symbol($libref,$symbol)
616
617
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618=item dl_find_symbol_anywhere()
619
620Syntax:
621
622 $symref = dl_find_symbol_anywhere($symbol)
623
624Applies dl_find_symbol() to the members of @dl_librefs and returns
625the first match found.
626
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627=item dl_undef_symbols()
628
629Example
630
631 @symbols = dl_undef_symbols()
632
633Return a list of symbol names which remain undefined after load_file().
634Returns C<()> if not known. Don't worry if your platform does not provide
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635a mechanism for this. Most do not need it and hence do not provide it,
636they just return an empty list.
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637
638
639=item dl_install_xsub()
640
641Syntax:
642
643 dl_install_xsub($perl_name, $symref [, $filename])
644
645Create a new Perl external subroutine named $perl_name using $symref as
646a pointer to the function which implements the routine. This is simply
647a direct call to newXSUB(). Returns a reference to the installed
648function.
649
650The $filename parameter is used by Perl to identify the source file for
651the function if required by die(), caller() or the debugger. If
652$filename is not defined then "DynaLoader" will be used.
653
654
1fef88e7 655=item bootstrap()
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656
657Syntax:
658
659bootstrap($module)
660
661This is the normal entry point for automatic dynamic loading in Perl.
662
663It performs the following actions:
664
665=over 8
666
667=item *
668
669locates an auto/$module directory by searching @INC
670
671=item *
672
673uses dl_findfile() to determine the filename to load
674
675=item *
676
677sets @dl_require_symbols to C<("boot_$module")>
678
679=item *
680
681executes an F<auto/$module/$module.bs> file if it exists
682(typically used to add to @dl_resolve_using any files which
683are required to load the module on the current platform)
684
685=item *
686
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687calls dl_load_flags() to determine how to load the file.
688
689=item *
690
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691calls dl_load_file() to load the file
692
693=item *
694
695calls dl_undef_symbols() and warns if any symbols are undefined
696
697=item *
698
699calls dl_find_symbol() for "boot_$module"
700
701=item *
702
703calls dl_install_xsub() to install it as "${module}::bootstrap"
704
705=item *
706
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707calls &{"${module}::bootstrap"} to bootstrap the module (actually
708it uses the function reference returned by dl_install_xsub for speed)
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709
710=back
711
712=back
713
714
715=head1 AUTHOR
716
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717Tim Bunce, 11 August 1994.
718
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719This interface is based on the work and comments of (in no particular
720order): Larry Wall, Robert Sanders, Dean Roehrich, Jeff Okamoto, Anno
c2960299 721Siegel, Thomas Neumann, Paul Marquess, Charles Bailey, myself and others.
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722
723Larry Wall designed the elegant inherited bootstrap mechanism and
724implemented the first Perl 5 dynamic loader using it.
725
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726Solaris global loading added by Nick Ing-Simmons with design/coding
727assistance from Tim Bunce, January 1996.
728
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730EOT
731
732close OUT or die $!;
733