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App::Info::Handler::Print(3pm) User Contributed Perl Documentation App::Info::Handler::Print(3pm)


App::Info::Handler::Print - Print App::Info event messages


  use App::Info::Category::FooApp;
  use App::Info::Handler::Print;
  my $stdout = App::Info::Handler::Print->new( fh => 'stdout' );
  my $app = App::Info::Category::FooApp->new( on_info => $stdout );
  # Or...
  my $app = App::Info::Category::FooApp->new( on_error => 'stderr' );


App::Info::Handler::Print objects handle App::Info events by printing their messages to a filehandle. This means that if you want event messages to print to a file or to a system filehandle, you can easily do it with this class. You'll find, however, that App::Info::Handler::Print is most effective for info and error events; unknown and prompt events are better handled by event handlers that know how to prompt users for data. See App::Info::Handler::Prompt for an example of that functionality.

Upon loading, App::Info::Handler::Print registers itself with App::Info::Handler, setting up a couple of strings that can be passed to an App::Info concrete subclass constructor. These strings are shortcuts that tell App::Info how to create the proper App::Info::Handler::Print object for handling events. The registered strings are:

Prints event messages to "STDOUT".
Prints event messages to "STDERR".

See the "new()" constructor below for how to have App::Info::Handler::Print print event messages to different filehandle.




  my $stderr_handler = App::Info::Handler::Print->new;
  $stderr_handler = App::Info::Handler::Print->new( fh => 'stderr' );
  my $stdout_handler = App::Info::Handler::Print->new( fh => 'stdout' );
  my $fh = FileHandle->new($file);
  my $fh_handler = App::Info::Handler::Print->new( fh => $fh );

Constructs a new App::Info::Handler::Print and returns it. It can take a single parameterized argument, "fh", which can be any one of the following values:

Constructs a App::Info::Handler::Print object that prints App::Info event messages to "STDERR".
Constructs a App::Info::Handler::Print object that prints App::Info event messages to "STDOUT".
Pass in a reference and App::Info::Handler::Print will assume that it's a filehandle reference that it can print to. Note that passing in something that can't be printed to will trigger an exception when App::Info::Handler::Print tries to print to it.

If the "fh" parameter is not passed, "new()" will default to creating an App::Info::Handler::Print object that prints App::Info event messages to "STDOUT".


This method is called by App::Info to print out the message from events.


This module is stored in an open GitHub repository <>. Feel free to fork and contribute!

Please file bug reports via GitHub Issues <> or by sending mail to <>.


David E. Wheeler <>


App::Info documents the event handling interface.

App::Info::Handler::Carp handles events by passing their messages Carp module functions.

App::Info::Handler::Prompt offers event handling more appropriate for unknown and confirm events.

App::Info::Handler describes how to implement custom App::Info event handlers.


Copyright (c) 2002-2011, David E. Wheeler. Some Rights Reserved.

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

2020-01-23 perl v5.30.0