Alien::Gnuplot - Find and verify functionality of the gnuplot executable.

       Craig DeForest <craig@deforest.org>

       (with special thanks to Chris Marshall, Juergen Mueck, and Sisyphus for  testing  and  debugging  on  the
       Microsoft platform)

       Copyright (C) 2013 Craig DeForest

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

perl v5.40.0                                       2024-10-20                                Alien::Gnuplot(3pm)

       On  POSIX  systems,  including  Linux  and  MacOS,  Alien::Gnuplot  uses  fork/exec to invoke the gnuplot
       executable and asynchronously monitor it for hangs.  Microsoft Windows process control is more difficult,
       so if $^O contains "MSWin32", a simpler system call is used, that is riskier -- it involves  waiting  for
       the unknown executable to complete.

       Alien::Gnuplot verifies existence and sanity of the gnuplot external application.  It only declares one
       access method, "Alien::Gnuplot::load_gnuplot", which does the actual work and is called automatically at
       load time.  Alien::Gnuplot doesn't have any actual plotting methods - making use of gnuplot, once it is
       found and verified, is up to you or your client module.

       Using Alien::Gnuplot checks for existence of the executable, verifies that it runs properly, and sets
       several global variables to describe the properties of the gnuplot it found:

       •  $Alien::Gnuplot::executable

          gets the path to the gnuplot executable.

       •  $Alien::Gnuplot::version

          gets the self-reported version number of the executable.

       •  $Alien::Gnuplot::pl

          gets the self-reported patch level.

       •  @Alien::Gnuplot::terms

          gets a list of the names of all supported terminal devices.

       •  %Alien::Gnuplot::terms

          gets  a  key for each supported terminal device; values are the 1-line description from gnuplot.  This
          is useful for testing whether a particular terminal is supported.

       •  @Alien::Gnuplot::colors

          gets a list of the names of all named colors recognized by this gnuplot.

       •  %Alien::Gnuplot::colors

          gets a key for each named color; values are the "#RRGGBB" form of  the  color.   This  is  useful  for
          decoding  colors,  or for checking whether a particular color name is recognized.  All the color names
          are lowercase alphanumeric.

       You can point Alien::Gnuplot to a particular path  for  gnuplot,  by  setting  the  environment  variable
       GNUPLOT_BINARY  to  the path.  Otherwise your path will be searched (using File::Spec) for the executable
       file.

       If there is no executable application in your path or in the location pointed to by GNUPLOT_BINARY,  then
       the module throws an exception.  You can also verify that it has not completed successfully, by examining
       $Alien::Gnuplot::version,  which  is undefined in case of failure and contains the gnuplot version string
       on success.

       If you think the global state of the gnuplot executable may have  changed,  you  can  either  reload  the
       module or explicitly call Alien::Gnuplot::load_gnuplot() to force a fresh inspection of the executable.

       When  you install Alien::Gnuplot, it checks that gnuplot itself is installed as well.  If it is not, then
       Alien::Gnuplot attempts to use one of several common package managers to install gnuplot for you.  If  it
       can't  find  one of those, if dies (and refuses to install), printing a friendly message about how to get
       gnuplot before throwing an error.

       In principle, gnuplot could be automagically downloaded and built, but it is distributed via  Sourceforge
       -- which obfuscates interior links, making such tools surprisingly difficult to write.

       Alien::Gnuplot - Find and verify functionality of the gnuplot executable.

       Gnuplot's main home page is at <https://gnuplot.sourceforge.net/>.

       Alien::Gnuplot development is at <https://github.com/drzowie/Alien-Gnuplot>.

       A   major   client   module   for  Alien::Gnuplot  is  PDL::Graphics::Gnuplot,  which  can  be  found  at
       <https://github.com/PDLPorters/PDL-Graphics-Gnuplot>.  PDL is at <https://pdl.perl.org/>.

        package MyGnuplotter;

        use strict;

        use Alien::Gnuplot;

        $gnuplot = $Alien::Gnuplot::executable;

        `$gnuplot < /tmp/plotfile`;

        1;