xref: /openbsd/gnu/usr.bin/perl/ext/DynaLoader/README (revision 09467b48)
1Perl 5 DynaLoader
2
3See DynaLoader.pm for detailed specification.
4
5This module is very similar to the other Perl 5 modules except that
6Configure selects which dl_*.xs file to use.
7
8After Configure has been run the Makefile.PL will generate a Makefile
9which will run xsubpp on a specific dl_*.xs file and write the output
10to DynaLoader.c
11
12After that the processing is the same as any other module.
13
14Note that, to be effective, the DynaLoader module must be _statically_
15linked into perl! Configure should arrange this.
16
17This interface is based on the work and comments of (in no particular
18order): Larry Wall, Robert Sanders, Dean Roehrich, Jeff Okamoto, Anno
19Siegel, Thomas Neumann, Paul Marquess, Charles Bailey and others.
20
21The dl_*.xs files should either be named after the dynamic linking
22operating system interface used if that interface is available on more
23than one type of system, e.g.:
24	dlopen  for dlopen()/dlsym() type functions (SunOS, BSD)
25or else the osname, e.g., hpux, next, vms etc.
26
27Both are determined by Configure and so only those specific names that
28Configure knows/uses will work.
29
30If porting the DynaLoader to a platform that has a core dynamic linking
31interface similar to an existing generic type, e.g., dlopen,
32please try to port the corresponding dl_*.xs file (using #ifdef's if
33required).
34
35Otherwise, or if that proves too messy, create a new dl_*.xs file named
36after your osname. Configure will give preference to a dl_$osname.xs
37file if one exists.
38
39The file dl_dlopen.xs is a reference implementation by Paul Marquess
40which is a good place to start if porting from scratch. The dlutils.c file
41holds some common definitions that are #included into the dl_*.xs files.
42
43After the initial implementation of a new DynaLoader dl_*.xs file you
44may need to edit or create ext/MODULE/MODULE.bs files (library bootstrap
45files) to reflect the needs of your platform and linking software.
46
47Refer to DynaLoader.pm, lib/ExtUtils/MakeMaker.pm and any existing
48ext/MODULE/MODULE.bs files for more information.
49
50Tim Bunce.
51August 1994
52