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

App::Info::Lib::Expat(3pm) User Contributed Perl Documentation App::Info::Lib::Expat(3pm)

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 (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.
2015-06-06 perl v5.20.2