package URI::Heuristic; =head1 NAME URI::Heuristic - Expand URI using heuristics =head1 SYNOPSIS use URI::Heuristic qw(uf_uristr); $u = uf_uristr("example"); # http://www.example.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 $u = uf_uristr("/etc/passwd"); # file:/etc/passwd =head1 DESCRIPTION This module provides functions that expand strings into real absolute URIs using some built-in heuristics. Strings that already represent absolute URIs (i.e. that start with a C<scheme:> part) are never modified and are returned unchanged. The main use of these functions is to allow abbreviated URIs similar to what many web browsers allow for URIs typed in by the user. The following functions are provided: =over 4 =item uf_uristr($str) Tries to make the argument string 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) Works the same way as uf_uristr() but returns a C<URI> object. =back =head1 ENVIRONMENT If the hostname portion of a URI does not contain any dots, then certain qualified guesses are made. These guesses are governed by the following environment variables: =over 10 =item COUNTRY The two-letter country code (ISO 3166) for your location. If the domain name of your host ends with two letters, then it is taken to be the default country. See also L<Locale::Country>. =item HTTP_ACCEPT_LANGUAGE, LC_ALL, LANG If COUNTRY is not set, these standard environment variables are examined and country (not language) information possibly found in them is used as the default country. =item URL_GUESS_PATTERN Contains a space-separated list of URL patterns to try. The string "ACME" is for some reason used as a placeholder for the host name in the URL provided. Example: URL_GUESS_PATTERN="www.ACME.no www.ACME.se www.ACME.com" export URL_GUESS_PATTERN Specifying URL_GUESS_PATTERN disables any guessing rules based on country. An empty URL_GUESS_PATTERN disables any guessing that involves host name lookups. =back =head1 COPYRIGHT Copyright 1997-1998, Gisle Aas This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =cut use strict; use warnings; use Exporter 5.57 'import'; our @EXPORT_OK = qw(uf_uri uf_uristr uf_url uf_urlstr); our $VERSION = '5.08'; our ($MY_COUNTRY, $DEBUG); sub MY_COUNTRY() { for ($MY_COUNTRY) { return $_ if defined; # First try the environment. $_ = $ENV{COUNTRY}; return $_ if defined; # Try the country part of LC_ALL and LANG from environment my @srcs = ($ENV{LC_ALL}, $ENV{LANG}); # ...and HTTP_ACCEPT_LANGUAGE before those if present if (my $httplang = $ENV{HTTP_ACCEPT_LANGUAGE}) { # TODO: q-value processing/ordering for $httplang (split(/\s*,\s*/, $httplang)) { if ($httplang =~ /^\s*([a-zA-Z]+)[_-]([a-zA-Z]{2})\s*$/) { unshift(@srcs, "${1}_${2}"); last; } } } for (@srcs) { next unless defined; return lc($1) if /^[a-zA-Z]+_([a-zA-Z]{2})(?:[.@]|$)/; } # Last bit of domain name. This may access the network. require Net::Domain; my $fqdn = Net::Domain::hostfqdn(); $_ = lc($1) if $fqdn =~ /\.([a-zA-Z]{2})$/; return $_ if defined; # Give up. Defined but false. return ($_ = 0); } } our %LOCAL_GUESSING = ( 'us' => [qw(www.ACME.gov www.ACME.mil)], 'gb' => [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> ); # Backwards compatibility; uk != United Kingdom in ISO 3166 $LOCAL_GUESSING{uk} = $LOCAL_GUESSING{gb}; sub uf_uristr ($) { local($_) = @_; print STDERR "uf_uristr: resolving $_\n" if $DEBUG; return unless defined; s/^\s+//; s/\s+$//; if (/^(www|web|home)[a-z0-9-]*(?:\.|$)/i) { $_ = "http://$_"; } elsif (/^(ftp|gopher|news|wais|https|http)[a-z0-9-]*(?:\.|$)/i) { $_ = lc($1) . "://$_"; } 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; my $scheme = "http"; if (/^:(\d+)\b/) { # Some more or less well known ports if ($1 =~ /^[56789]?443$/) { $scheme = "https"; } elsif ($1 eq "21") { $scheme = "ftp"; } } if ($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; } } $_ = "$scheme://$host$_"; } 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;