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Otherwise, the libraries specified by C<$Config{perllibs}> (see Config.pm)
will be appended to the list of C<$potential_libs>.  The libraries
will be searched for in the directories specified in C<$potential_libs>,
C<$Config{libpth}>, and in C<$Config{installarchlib}/CORE>.
For each library that is found,  a space-separated list of fully qualified
library pathnames is generated.

=item *

Input library and path specifications are accepted with or without the
C<-l> and C<-L> prefixes used by Unix linkers.

An entry of the form C<-La:\foo> specifies the C<a:\foo> directory to look
for the libraries that follow.

An entry of the form C<-lfoo> specifies the library C<foo>, which may be
spelled differently depending on what kind of compiler you are using.  If
you are using GCC, it gets translated to C<libfoo.a>, but for other win32
compilers, it becomes C<foo.lib>.  If no files are found by those translated
names, one more attempt is made to find them using either C<foo.a> or
C<libfoo.lib>, depending on whether GCC or some other win32 compiler is
being used, respectively.

If neither the C<-L> or C<-l> prefix is present in an entry, the entry is
considered a directory to search if it is in fact a directory, and a
library to search for otherwise.  The C<$Config{lib_ext}> suffix will
be appended to any entries that are not directories and don't already have
the suffix.

Note that the C<-L> and C<-l> prefixes are B<not required>, but authors
who wish their extensions to be portable to Unix or OS/2 should use the
prefixes, since the Unix-OS/2 version of ext() requires them.

=item *

Entries cannot be plain object files, as many Win32 compilers will
not handle object files in the place of libraries.

=item *

Entries in C<$potential_libs> beginning with a colon and followed by
alphanumeric characters are treated as flags.  Unknown flags will be ignored.

An entry that matches C</:nodefault/i> disables the appending of default
libraries found in C<$Config{perllibs}> (this should be only needed very rarely).

An entry that matches C</:nosearch/i> disables all searching for
the libraries specified after it.  Translation of C<-Lfoo> and
C<-lfoo> still happens as appropriate (depending on compiler being used,
as reflected by C<$Config{cc}>), but the entries are not verified to be
valid files or directories.

An entry that matches C</:search/i> reenables searching for
the libraries specified after it.  You can put it at the end to
enable searching for default libraries specified by C<$Config{perllibs}>.

=item *

The libraries specified may be a mixture of static libraries and
import libraries (to link with DLLs).  Since both kinds are used
pretty transparently on the Win32 platform, we do not attempt to
distinguish between them.

=item *

LDLOADLIBS and EXTRALIBS are always identical under Win32, and BSLOADLIBS
and LD_RUN_PATH are always empty (this may change in future).

=item *

You must make sure that any paths and path components are properly
surrounded with double-quotes if they contain spaces. For example,
C<$potential_libs> could be (literally):

	"-Lc:\Program Files\vc\lib" msvcrt.lib "la test\foo bar.lib"

Note how the first and last entries are protected by quotes in order
to protect the spaces.

=item *

Since this module is most often used only indirectly from extension
C<Makefile.PL> files, here is an example C<Makefile.PL> entry to add
a library to the build process for an extension:

        LIBS => ['-lgl']

When using GCC, that entry specifies that MakeMaker should first look
for C<libgl.a> (followed by C<gl.a>) in all the locations specified by
C<$Config{libpth}>.

When using a compiler other than GCC, the above entry will search for
C<gl.lib> (followed by C<libgl.lib>).

If the library happens to be in a location not in C<$Config{libpth}>,
you need:

        LIBS => ['-Lc:\gllibs -lgl']

Here is a less often used example:

        LIBS => ['-lgl', ':nosearch -Ld:\mesalibs -lmesa -luser32']

This specifies a search for library C<gl> as before.  If that search
fails to find the library, it looks at the next item in the list. The
C<:nosearch> flag will prevent searching for the libraries that follow,
so it simply returns the value as C<-Ld:\mesalibs -lmesa -luser32>,
since GCC can use that value as is with its linker.

When using the Visual C compiler, the second item is returned as
C<-libpath:d:\mesalibs mesa.lib user32.lib>.

When using the Borland compiler, the second item is returned as
C<-Ld:\mesalibs mesa.lib user32.lib>, and MakeMaker takes care of
moving the C<-Ld:\mesalibs> to the correct place in the linker
command line.

=back


=head1 SEE ALSO