Provided by: libffi-platypus-perl_0.83-1_amd64 bug


       FFI::Platypus::DL - Slightly non-portable interface to libdl


       version 0.83


        use FFI::Platypus;
        use FFI::Platypus::DL;

        my $handle = dlopen("./", RTLD_PLATYPUS_DEFAULT);
        my $address = dlsym($handle, "my_function_named_foo");
        my $ffi = FFI::Platypus->new;
        $ffi->function($address => [] => 'void')->call;


       This module provides an interface to libdl, the dynamic loader on UNIX.  The underlying
       interface has always been used by FFI::Platypus, but it wasn't a public interface until
       version 0.52.  The name was changed with that version when it became a public interface,
       so be sure to specify that version if you are going to use it.

       It is somewhat non-portable for these reasons:

       GNU extensions
           It provides some GNU extensions to platforms such as Linux that support them.

           It provides an emulation layer on Windows.  The emulation layer only supports
           "RTLD_PLATYPUS_DEFAULT" as a flag.  The emulation layer emulates the convention
           described below of passing "undef" as the dynamic library name to mean, use the
           currently running executable.  I've used it without any problems for years, but
           Windows is not my main development platform.


        my $handle = dlopen($filename, $flags);

       This opens a dynamic library in the context of the dynamic loader.  $filename is the full
       or relative path to a dynamic library (usually a ".so" on Linux and some other UNIXen, a
       ".dll" on Windows and a ".dylib" on OS X).  $flags are flags that can be used to alter the
       behavior of the library and the symbols it contains.  The return value is an opaque
       pointer or $handle which can be used to look up symbols with "dlsym".  The handle should
       be closed with "dlclose" when you are done with it.

       By convention if you pass in "undef" for the filename, the currently loaded executable
       will be used instead of a separate dynamic library.  This is the easiest and most portable
       way to find the address of symbols in the standard C library.  This convention is baked
       into most UNIXen, but this capability is emulated in Windows which doesn't come with the
       capability out of the box.

       If there is an error in opening the library then "undef" will be returned and the
       diagnostic for the failure can be retrieved with "dlerror" as described below.

       Not all flags are supported on all platforms.  You can test if a flag is available using


       Typically where flags are not mutually exclusive, they can be or'd together:

        my $handle = dlopen("", RTLD_LAZY | RTLD_GLOBAL);

       Check your operating system documentation for detailed descriptions of these flags.

           This is the FFI::Platypus default for "dlopen" (NOTE: NOT the libdl default).  This is
           the only flag supported on Windows.  For historical reasons, this is usually
           "RTLD_LAZY" on Unix and 0 on Windows.

           Perform lazy binding.

           Resolve all symbols before returning from "dlopen".  Error if all symbols cannot

           Symbols are shared.

           Symbols are NOT shared.

           glibc 2.2 extension.

           glibc 2.2 extension.

           glibc 2.3.4 extension.

        my $opaque = dlsym($handle, $symbol);

       This looks up the given $symbol in the library pointed to by $handle.  If the symbol is
       found, the address for that symbol is returned as an opaque pointer.  This pointer can be
       passed into the FFI::Platypus "function" and "attach" methods instead of a function name.

       If the symbol cannot be found then "undef" will be returned and the diagnostic for the
       failure can be retrieved with "dlerror" as described below.

        my $status = dlclose($handle);

       On success, "dlclose" returns 0; on error, it returns a nonzero value, and the diagnostic
       for the failure can be retrieved with "dlerror" as described below.

        my $error_string = dlerror;

       Returns the human readable diagnostic for the reason for the failure for the most recent
       "dl" prefixed function call.


       Some flags for "dlopen" are not portable.  This module may not be supported platforms
       added to FFI::Platypus in the future.  It does work as far as I know on all of the
       currently supported platforms.




       Author: Graham Ollis <>


       Bakkiaraj Murugesan (bakkiaraj)

       Dylan Cali (calid)


       Zaki Mughal (zmughal)

       Fitz Elliott (felliott)

       Vickenty Fesunov (vyf)

       Gregor Herrmann (gregoa)

       Shlomi Fish (shlomif)

       Damyan Ivanov

       Ilya Pavlov (Ilya33)


       This software is copyright (c) 2015,2016,2017,2018,2019 by Graham Ollis.

       This is free software; you can redistribute it and/or modify it under the same terms as
       the Perl 5 programming language system itself.