App::Info::Lib::Expat(3p)

NAME
App::Info::Lib::Expat - Information about the Expat XML parser

SYNOPSIS
  use App::Info::Lib::Expat;

  my $expat = App::Info::Lib::Expat->new;

  if ($expat->installed) {
      print "App name: ", $expat->name, "\n";
      print "Version:  ", $expat->version, "\n";
      print "Bin dir:  ", $expat->bin_dir, "\n";
  } else {
      print "Expat is not installed. :-(\n";
  }

DESCRIPTION
App::Info::Lib::Expat supplies information about the Expat XML parser installed on the local system. It implements all of the methods defined by App::Info::Lib. Methods that trigger events will trigger them only the first time they're called (See App::Info for documentation on handling events). To start over (after, say, someone has installed Expat) construct a new App::Info::Lib::Expat object to aggregate new meta data.

Some of the methods trigger the same events. This is due to cross-calling of shared subroutines. However, any one event should be triggered no more than once. For example, although the info event "Searching for 'expat.h'" is documented for the methods version(), major_version(), minor_version(), and patch_version(), rest assured that it will only be triggered once, by whichever of those four methods is called first.

INTERFACE

  Constructor
new

  my $expat = App::Info::Lib::Expat->new(@params);

Returns an App::Info::Lib::Expat object. See App::Info for a complete description of argument parameters.

When called, new() searches all of the paths returned by the search_lib_dirs() method for one of the files returned by the search_lib_names() method. If any of is found, then Expat is assumed to be installed. Otherwise, most of the object methods will return "undef".

Events:

info
    Searching for Expat libraries

confirm
    Path to Expat library directory?

unknown
    Path to Expat library directory?

  Class Method
key_name

  my $key_name = App::Info::Lib::Expat->key_name;

Returns the unique key name that describes this class. The value returned is the string "Expat".

  Object Methods
installed

  print "Expat is ", ($expat->installed ? '' : 'not '),
    "installed.\n";

Returns true if Expat is installed, and false if it is not. App::Info::Lib::Expat determines whether Expat is installed based on the presence or absence on the file system of one of the files searched for when new() constructed the object. If Expat does not appear to be installed, then most of the other object methods will return empty values.

name

  my $name = $expat->name;

Returns the name of the application. In this case, name() simply returns the string "Expat".

version

Returns the full version number for Expat. App::Info::Lib::Expat attempts parse the version number from the expat.h file, if it exists.

Events:

info
    Searching for 'expat.h'

    Searching for include directory

error
    Cannot find include directory

    Cannot find 'expat.h'

    Failed to parse version from 'expat.h'

unknown
    Enter a valid Expat include directory

    Enter a valid Expat version number

major_version

  my $major_version = $expat->major_version;

Returns the Expat major version number. App::Info::Lib::Expat attempts to parse the version number from the expat.h file, if it exists. For example, if version() returns "1.95.2", then this method returns "1".

Events:

info
    Searching for 'expat.h'

    Searching for include directory

error
    Cannot find include directory

    Cannot find 'expat.h'

    Failed to parse version from 'expat.h'

unknown
    Enter a valid Expat include directory

    Enter a valid Expat major version number

minor_version

  my $minor_version = $expat->minor_version;

Returns the Expat minor version number. App::Info::Lib::Expat attempts to parse the version number from the expat.h file, if it exists. For example, if version() returns "1.95.2", then this method returns "95".

Events:

info
    Searching for 'expat.h'

    Searching for include directory

error
    Cannot find include directory

    Cannot find 'expat.h'

    Failed to parse version from 'expat.h'

unknown
    Enter a valid Expat include directory

    Enter a valid Expat minor version number

patch_version

  my $patch_version = $expat->patch_version;

Returns the Expat patch version number. App::Info::Lib::Expat attempts to parse the version number from the expat.h file, if it exists. For example, version() returns "1.95.2", then this method returns "2".

Events:

info
    Searching for 'expat.h'

    Searching for include directory

error
    Cannot find include directory

    Cannot find 'expat.h'

    Failed to parse version from 'expat.h'

unknown
    Enter a valid Expat include directory

    Enter a valid Expat patch version number

bin_dir

  my $bin_dir = $expat->bin_dir;

Since Expat includes no binaries, this method always returns false.

executable

  my $executable = $expat->executable;

Since Expat includes no executable program, this method always returns false.

inc_dir

  my $inc_dir = $expat->inc_dir;

Returns the directory path in which the file expat.h was found. App::Info::Lib::Expat searches for expat.h in the following directories:

/usr/local/include
/usr/include
/sw/include

Events:

info
    Searching for include directory

error
    Cannot find include directory

unknown
    Enter a valid Expat include directory

lib_dir

  my $lib_dir = $expat->lib_dir;

Returns the directory path in which a Expat library was found. The files and paths searched are as described for the "new" constructor, as are the events.

so_lib_dir

  my $so_lib_dir = $expat->so_lib_dir;

Returns the directory path in which a Expat shared object library was found. It searches all of the paths in the "libsdirs" and "loclibpth" attributes defined by the Perl Config module -- plus /sw/lib (for all you Fink fans) -- for one of the following files:

libexpat.so
libexpat.so.0
libexpat.so.0.0.1
libexpat.dylib
libexpat.0.dylib
libexpat.0.0.1.dylib

Events:

info
    Searching for shared object library directory

error
    Cannot find shared object library directory

unknown
    Enter a valid Expat shared object library directory

home_url

  my $home_url = $expat->home_url;

Returns the libexpat home page URL.

download_url

  my $download_url = $expat->download_url;

Returns the libexpat download URL.

search_lib_names

  my @seach_lib_names = $self->search_lib_nams

Returns a list of possible names for library files. Used by lib_dir() to search for library files. By default, the list is:

libexpat.a
libexpat.la
libexpat.so
libexpat.so.0
libexpat.so.0.0.1
libexpat.dylib
libexpat.0.dylib
libexpat.0.0.1.dylib

search_so_lib_names

  my @seach_so_lib_names = $self->search_so_lib_nams

Returns a list of possible names for shared object library files. Used by so_lib_dir() to search for library files. By default, the list is:

libexpat.so
libexpat.so.0
libexpat.so.0.0.1
libexpat.dylib
libexpat.0.dylib
libexpat.0.0.1.dylib

search_lib_dirs

  my @search_lib_dirs = $expat->search_lib_dirs;

Returns a list of possible directories in which to search for libraries. By default, it returns all of the paths in the "libsdirs" and "loclibpth" attributes defined by the Perl Config module -- plus /sw/lib (in support of all you Fink users out there).

search_inc_names

  my @search_inc_names = $expat->search_inc_names;

Returns a list of include file names to search for. Used by inc_dir() to search for an include file. By default, the only name returned is expat.h.

search_inc_dirs

  my @search_inc_dirs = $expat->search_inc_dirs;

Returns a list of possible directories in which to search for include files. Used by inc_dir() to search for an include file. By default, the directories are:

/usr/local/include
/usr/include
/sw/include

KNOWN ISSUES
This is a pretty simple class. It's possible that there are more directories that ought to be searched for libraries and includes. And if anyone knows how to get the version numbers, let me know!

The format of the version number seems to have changed recently (1.95.1-2), and now I don't know where to find the version number. Patches welcome.

SUPPORT
This module is stored in an open GitHub repository <http://github.com/theory/app-info/>. Feel free to fork and contribute!

Please file bug reports via GitHub Issues <http://github.com/theory/app-info/issues/> or by sending mail to bug-App-Info@rt.cpan.org <mailto:bug-App-Info@rt.cpan.org>.

AUTHOR
David E. Wheeler <david@justatheory.com> based on code by Sam Tregar <sam@tregar.com> that Sam, in turn, borrowed from Clark Cooper's XML::Parser module.

SEE ALSO
App::Info documents the event handling interface.

App::Info::Lib is the App::Info::Lib::Expat parent class.

XML::Parser uses Expat to parse XML.

Config provides Perl configure-time information used by App::Info::Lib::Expat to locate Expat libraries and files.

<http://expat.sourceforge.net/> is the Expat home page.

COPYRIGHT AND LICENSE
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.