ExtUtils::Embed(3)

NAME
ExtUtils::Embed - Utilities for embedding Perl in C/C++ applications

SYNOPSIS
 perl -MExtUtils::Embed -e xsinit
 perl -MExtUtils::Embed -e ccopts
 perl -MExtUtils::Embed -e ldopts

DESCRIPTION
"ExtUtils::Embed" provides utility functions for embedding a Perl interpreter and extensions in your C/C++ applications. Typically, an application Makefile will invoke "ExtUtils::Embed" functions while building your application.

@EXPORT
"ExtUtils::Embed" exports the following functions:

xsinit(), ldopts(), ccopts(), perl_inc(), ccflags(), ccdlflags(), xsi_header(), xsi_protos(), xsi_body()

FUNCTIONS

xsinit()
    Generate C/C++ code for the XS initializer function.

    When invoked as "`perl -MExtUtils::Embed -e xsinit --`" the following options are recognized:

    -o <output filename> (Defaults to perlxsi.c)

    -o STDOUT will print to STDOUT.

    -std (Write code for extensions that are linked with the current Perl.)

    Any additional arguments are expected to be names of modules to generate code for.

    When invoked with parameters the following are accepted and optional:

    "xsinit($filename,$std,[@modules])"

    Where,

    $filename is equivalent to the -o option.

    $std is boolean, equivalent to the -std option.

    [@modules] is an array ref, same as additional arguments mentioned above.

Examples
     perl -MExtUtils::Embed -e xsinit -- -o xsinit.c Socket

    This will generate code with an "xs_init" function that glues the perl "Socket::bootstrap" function to the C "boot_Socket" function and writes it to a file named xsinit.c.

    Note that DynaLoader is a special case where it must call "boot_DynaLoader" directly.

     perl -MExtUtils::Embed -e xsinit

    This will generate code for linking with "DynaLoader" and each static extension found in $Config{static_ext}. The code is written to the default file name perlxsi.c.

     perl -MExtUtils::Embed -e xsinit -- -o xsinit.c \
                                -std DBI DBD::Oracle

    Here, code is written for all the currently linked extensions along with code for "DBI" and "DBD::Oracle".

    If you have a working "DynaLoader" then there is rarely any need to statically link in any other extensions.

ldopts()
    Output arguments for linking the Perl library and extensions to your application.

    When invoked as "`perl -MExtUtils::Embed -e ldopts --`" the following options are recognized:

    -std

    Output arguments for linking the Perl library and any extensions linked with the current Perl.

    -I <path1:path2>

    Search path for ModuleName.a archives. Default path is @INC. Library archives are expected to be found as /some/path/auto/ModuleName/ModuleName.a For example, when looking for Socket.a relative to a search path, we should find auto/Socket/Socket.a

    When looking for "DBD::Oracle" relative to a search path, we should find auto/DBD/Oracle/Oracle.a

    Keep in mind that you can always supply /my/own/path/ModuleName.a as an additional linker argument.

    -- <list of linker args>

    Additional linker arguments to be considered.

    Any additional arguments found before the -- token are expected to be names of modules to generate code for.

    When invoked with parameters the following are accepted and optional:

    "ldopts($std,[@modules],[@link_args],$path)"

    Where:

    $std is boolean, equivalent to the -std option.

    [@modules] is equivalent to additional arguments found before the -- token.

    [@link_args] is equivalent to arguments found after the -- token.

    $path is equivalent to the -I option.

    In addition, when ldopts is called with parameters, it will return the argument string rather than print it to STDOUT.

Examples
     perl -MExtUtils::Embed -e ldopts

    This will print arguments for linking with "libperl" and extensions found in $Config{static_ext}. This includes libraries found in $Config{libs} and the first ModuleName.a library for each extension that is found by searching @INC or the path specified by the -I option. In addition, when ModuleName.a is found, additional linker arguments are picked up from the extralibs.ld file in the same directory.

     perl -MExtUtils::Embed -e ldopts -- -std Socket

    This will do the same as the above example, along with printing additional arguments for linking with the "Socket" extension.

     perl -MExtUtils::Embed -e ldopts -- -std Msql -- \
                            -L/usr/msql/lib -lmsql

    Any arguments after the second '--' token are additional linker arguments that will be examined for potential conflict. If there is no conflict, the additional arguments will be part of the output.

perl_inc()
    For including perl header files this function simply prints:

     -I$Config{archlibexp}/CORE

    So, rather than having to say:

     perl -MConfig -e 'print "-I$Config{archlibexp}/CORE"'

    Just say:

     perl -MExtUtils::Embed -e perl_inc

ccflags(), ccdlflags()
    These functions simply print $Config{ccflags} and $Config{ccdlflags}

ccopts()
    This function combines "perl_inc()", "ccflags()" and "ccdlflags()" into one.

xsi_header()
    This function simply returns a string defining the same "EXTERN_C" macro as perlmain.c along with #including perl.h and EXTERN.h.

xsi_protos(@modules)
    This function returns a string of "boot_$ModuleName" prototypes for each @modules.

xsi_body(@modules)
    This function returns a string of calls to "newXS()" that glue the module bootstrap function to boot_ModuleName for each @modules.

    "xsinit()" uses the xsi_* functions to generate most of its code.

EXAMPLES
For examples on how to use "ExtUtils::Embed" for building C/C++ applications with embedded perl, see perlembed.

SEE ALSO
perlembed

AUTHOR
Doug MacEachern <"dougm@osf.org">

Based on ideas from Tim Bunce <"Tim.Bunce@ig.co.uk"> and minimod.pl by Andreas Koenig <"k@anna.in-berlin.de"> and Tim Bunce.