1package URI::gopher;  # <draft-murali-url-gopher>, Dec 4, 1996
2
3require URI::_server;
4@ISA=qw(URI::_server);
5
6use strict;
7use URI::Escape qw(uri_unescape);
8
9#  A Gopher URL follows the common internet scheme syntax as defined in
10#  section 4.3 of [RFC-URL-SYNTAX]:
11#
12#        gopher://<host>[:<port>]/<gopher-path>
13#
14#  where
15#
16#        <gopher-path> :=  <gopher-type><selector> |
17#                          <gopher-type><selector>%09<search> |
18#                          <gopher-type><selector>%09<search>%09<gopher+_string>
19#
20#        <gopher-type> := '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7'
21#                         '8' | '9' | '+' | 'I' | 'g' | 'T'
22#
23#        <selector>    := *pchar     Refer to RFC 1808 [4]
24#        <search>      := *pchar
25#        <gopher+_string> := *uchar  Refer to RFC 1738 [3]
26#
27#  If the optional port is omitted, the port defaults to 70.
28
29sub default_port { 70 }
30
31sub _gopher_type
32{
33    my $self = shift;
34    my $path = $self->path_query;
35    $path =~ s,^/,,;
36    my $gtype = $1 if $path =~ s/^(.)//s;
37    if (@_) {
38	my $new_type = shift;
39	if (defined($new_type)) {
40	    Carp::croak("Bad gopher type '$new_type'")
41               unless length($new_type) == 1;
42	    substr($path, 0, 0) = $new_type;
43	    $self->path_query($path);
44	} else {
45	    Carp::croak("Can't delete gopher type when selector is present")
46		if length($path);
47	    $self->path_query(undef);
48	}
49    }
50    return $gtype;
51}
52
53sub gopher_type
54{
55    my $self = shift;
56    my $gtype = $self->_gopher_type(@_);
57    $gtype = "1" unless defined $gtype;
58    $gtype;
59}
60
61*gtype = \&gopher_type;  # URI::URL compatibility
62
63sub selector { shift->_gfield(0, @_) }
64sub search   { shift->_gfield(1, @_) }
65sub string   { shift->_gfield(2, @_) }
66
67sub _gfield
68{
69    my $self = shift;
70    my $fno  = shift;
71    my $path = $self->path_query;
72
73    # not according to spec., but many popular browsers accept
74    # gopher URLs with a '?' before the search string.
75    $path =~ s/\?/\t/;
76    $path = uri_unescape($path);
77    $path =~ s,^/,,;
78    my $gtype = $1 if $path =~ s,^(.),,s;
79    my @path = split(/\t/, $path, 3);
80    if (@_) {
81	# modify
82	my $new = shift;
83	$path[$fno] = $new;
84	pop(@path) while @path && !defined($path[-1]);
85	for (@path) { $_="" unless defined }
86	$path = $gtype;
87	$path = "1" unless defined $path;
88	$path .= join("\t", @path);
89	$self->path_query($path);
90    }
91    $path[$fno];
92}
93
941;
95