package URI::Heuristic;# $Id: Heuristic.pm,v 4.13 2002/01/16 23:26:09 gisle Exp $=head1 NAMEuf_uristr - Expand URI using heuristics=head1 SYNOPSIS use URI::Heuristic qw(uf_uristr); $u = uf_uristr("perl");             # http://www.perl.com $u = uf_uristr("www.sol.no/sol");   # http://www.sol.no/sol $u = uf_uristr("aas");              # http://www.aas.no $u = uf_uristr("ftp.funet.fi");     # ftp://ftp.funet.fi $u = uf_uristr("/etc/passwd");      # file:/etc/passwd=head1 DESCRIPTIONThis module provides functions that expand strings into real absoluteURIs using some builtin heuristics.  Strings that already representabsolute URIs (i.e. start with a C<scheme:> part) are never modifiedand are returned unchanged.  The main use of these functions are toallow abbreviated URIs similar to what many web browsers allow for URIstyped in by the user.The following functions are provided:=over 4=item uf_uristr($str)The uf_uristr() function will try to make the string passed as argument into a proper absolute URI string.  The "uf_" prefix stands for "User Friendly".  Under MacOS, it assumes that any string with a common URL scheme (http, ftp, etc.) is a URL rather than a local path.  So don't name your volumes after common URL schemes and expect uf_uristr() to construct valid file: URL's on those volumes for you, because it won't.=item uf_uri($str)This functions work the same way as uf_uristr() but it willreturn a C<URI> object.=back=head1 ENVIRONMENTIf the hostname portion of a URI does not contain any dots, thencertain qualified guesses will be made.  These guesses are governed bethe following two environment variables.=over 10=item COUNTRYThis is the two letter country code (ISO 3166) for your location.  Ifthe domain name of your host ends with two letters, then it is takento be the default country. See also L<Locale::Country>.=item URL_GUESS_PATTERNContain a space separated list of URL patterns to try.  The string"ACME" is for some reason used as a placeholder for the host name inthe URL provided.  Example: URL_GUESS_PATTERN="www.ACME.no www.ACME.se www.ACME.com" export URL_GUESS_PATTERNSpecifying URL_GUESS_PATTERN disables any guessing rules based oncountry.  An empty URL_GUESS_PATTERN disables any guessing thatinvolves host name lookups.=back=head1 COPYRIGHTCopyright 1997-1998, Gisle AasThis library is free software; you can redistribute it and/ormodify it under the same terms as Perl itself.=cutuse strict;use vars qw(@EXPORT_OK $VERSION $MY_COUNTRY %LOCAL_GUESSING $DEBUG);require Exporter;*import = \&Exporter::import;@EXPORT_OK = qw(uf_uri uf_uristr uf_url uf_urlstr);$VERSION = sprintf("%d.%02d", q$Revision: 4.13 $ =~ /(\d+)\.(\d+)/);eval {    require Net::Domain;    my $fqdn = Net::Domain::hostfqdn();    $MY_COUNTRY = lc($1) if $fqdn =~ /\.([a-zA-Z]{2})$/;    # Some other heuristics to guess country?  Perhaps looking    # at some environment variable (LANG, LC_ALL, ???)    $MY_COUNTRY = $ENV{COUNTRY} if exists $ENV{COUNTRY};};%LOCAL_GUESSING =( 'us' => [qw(www.ACME.gov www.ACME.mil)], 'uk' => [qw(www.ACME.co.uk www.ACME.org.uk www.ACME.ac.uk)], 'au' => [qw(www.ACME.com.au www.ACME.org.au www.ACME.edu.au)], 'il' => [qw(www.ACME.co.il www.ACME.org.il www.ACME.net.il)], # send corrections and new entries to <gisle@aas.no>);sub uf_uristr ($){    local($_) = @_;    print STDERR "uf_uristr: resolving $_\n" if $DEBUG;    return unless defined;    s/^\s+//;    s/\s+$//;    if (/^(www|web|home)\./) {	$_ = "http://$_";    } elsif (/^(ftp|gopher|news|wais|http|https)\./) {	$_ = "$1://$_";    } elsif ($^O ne "MacOS" && 	    (m,^/,      ||          # absolute file name	     m,^\.\.?/, ||          # relative file name	     m,^[a-zA-Z]:[/\\],)    # dosish file name	    )    {	$_ = "file:$_";    } elsif ($^O eq "MacOS" && m/:/) {        # potential MacOS file name	unless (m/^(ftp|gopher|news|wais|http|https|mailto):/) {	    require URI::file;	    my $a = URI::file->new($_)->as_string;	    $_ = ($a =~ m/^file:/) ? $a : "file:$a";	}    } elsif (/^\w+([\.\-]\w+)*\@(\w+\.)+\w{2,3}$/) {	$_ = "mailto:$_";    } elsif (!/^[a-zA-Z][a-zA-Z0-9.+\-]*:/) {      # no scheme specified	if (s/^([-\w]+(?:\.[-\w]+)*)([\/:\?\#]|$)/$2/) {	    my $host = $1;	    if ($host !~ /\./ && $host ne "localhost") {		my @guess;		if (exists $ENV{URL_GUESS_PATTERN}) {		    @guess = map { s/\bACME\b/$host/; $_ }		             split(' ', $ENV{URL_GUESS_PATTERN});		} else {		    if ($MY_COUNTRY) {			my $special = $LOCAL_GUESSING{$MY_COUNTRY};			if ($special) {			    my @special = @$special;			    push(@guess, map { s/\bACME\b/$host/; $_ }                                               @special);			} else {			    push(@guess, "www.$host.$MY_COUNTRY");			}		    }		    push(@guess, map "www.$host.$_",			             "com", "org", "net", "edu", "int");		}		my $guess;		for $guess (@guess) {		    print STDERR "uf_uristr: gethostbyname('$guess')..."		      if $DEBUG;		    if (gethostbyname($guess)) {			print STDERR "yes\n" if $DEBUG;			$host = $guess;			last;		    }		    print STDERR "no\n" if $DEBUG;		}	    }	    $_ = "http://$host$_";	} else {	    # pure junk, just return it unchanged...	}    }    print STDERR "uf_uristr: ==> $_\n" if $DEBUG;    $_;}sub uf_uri ($){    require URI;    URI->new(uf_uristr($_[0]));}# legacy*uf_urlstr = \*uf_uristr;sub uf_url ($){    require URI::URL;    URI::URL->new(uf_uristr($_[0]));}1;