# phpman > man > ExtUtils::Mksymlists

## NAME
    [ExtUtils::Mksymlists](https://www.chedong.com/phpMan.php/perldoc/ExtUtils%3A%3AMksymlists/markdown) - write linker options files for dynamic extension

## SYNOPSIS
        use [ExtUtils::Mksymlists](https://www.chedong.com/phpMan.php/perldoc/ExtUtils%3A%3AMksymlists/markdown);
        Mksymlists(  NAME     => $name ,
                     DL_VARS  => [ $var1, $var2, $var3 ],
                     DL_FUNCS => { $pkg1 => [ $func1, $func2 ],
                                   $pkg2 => [ $func3 ] );

## DESCRIPTION
    "[ExtUtils::Mksymlists](https://www.chedong.com/phpMan.php/perldoc/ExtUtils%3A%3AMksymlists/markdown)" produces files used by the linker under some OSs during the creation of
    shared libraries for dynamic extensions. It is normally called from a MakeMaker-generated
    Makefile when the extension is built. The linker option file is generated by calling the
    function "Mksymlists", which is exported by default from "[ExtUtils::Mksymlists](https://www.chedong.com/phpMan.php/perldoc/ExtUtils%3A%3AMksymlists/markdown)". It takes one
    argument, a list of key-value pairs, in which the following keys are recognized:

    DLBASE
        This item specifies the name by which the linker knows the extension, which may be different
        from the name of the extension itself (for instance, some linkers add an '_' to the name of
        the extension). If it is not specified, it is derived from the NAME attribute. It is
        presently used only by OS2 and Win32.

    DL_FUNCS
        This is identical to the DL_FUNCS attribute available via MakeMaker, from which it is
        usually taken. Its value is a reference to an associative array, in which each key is the
        name of a package, and each value is an a reference to an array of function names which
        should be exported by the extension. For instance, one might say "DL_FUNCS => { [Homer::Iliad](https://www.chedong.com/phpMan.php/perldoc/Homer%3A%3AIliad/markdown)
        => [ qw(trojans greeks) ], [Homer::Odyssey](https://www.chedong.com/phpMan.php/perldoc/Homer%3A%3AOdyssey/markdown) => [ qw(travellers family suitors) ] }". The
        function names should be identical to those in the XSUB code; "Mksymlists" will alter the
        names written to the linker option file to match the changes made by xsubpp. In addition, if
        none of the functions in a list begin with the string boot_, "Mksymlists" will add a
        bootstrap function for that package, just as xsubpp does. (If a boot_<pkg> function is
        present in the list, it is passed through unchanged.) If DL_FUNCS is not specified, it
        defaults to the bootstrap function for the extension specified in NAME.

    DL_VARS
        This is identical to the DL_VARS attribute available via MakeMaker, and, like DL_FUNCS, it
        is usually specified via MakeMaker. Its value is a reference to an array of variable names
        which should be exported by the extension.

    FILE
        This key can be used to specify the name of the linker option file (minus the OS-specific
        extension), if for some reason you do not want to use the default value, which is the last
        word of the NAME attribute (*e.g.* for "[Tk::Canvas](https://www.chedong.com/phpMan.php/perldoc/Tk%3A%3ACanvas/markdown)", FILE defaults to "Canvas").

    FUNCLIST
        This provides an alternate means to specify function names to be exported from the
        extension. Its value is a reference to an array of function names to be exported by the
        extension. These names are passed through unaltered to the linker options file. Specifying a
        value for the FUNCLIST attribute suppresses automatic generation of the bootstrap function
        for the package. To still create the bootstrap name you have to specify the package name in
        the DL_FUNCS hash:

            Mksymlists(  NAME     => $name ,
                         FUNCLIST => [ $func1, $func2 ],
                         DL_FUNCS => { $pkg => [] } );

    IMPORTS
        This attribute is used to specify names to be imported into the extension. It is currently
        only used by OS/2 and Win32.

    NAME
        This gives the name of the extension (*e.g.* "[Tk::Canvas](https://www.chedong.com/phpMan.php/perldoc/Tk%3A%3ACanvas/markdown)") for which the linker option file
        will be produced.

    When calling "Mksymlists", one should always specify the NAME attribute. In most cases, this is
    all that's necessary. In the case of unusual extensions, however, the other attributes can be
    used to provide additional information to the linker.

## AUTHOR
    Charles Bailey *<<bailey@newman.upenn.edu>>*

## REVISION
    Last revised 14-Feb-1996, for Perl 5.002.