1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
# Copyright © 2010 Raphaël Hertzog <hertzog@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
package Dpkg::Compression;
use strict;
use warnings;
use base qw(Exporter);
our @EXPORT = qw($compression_re_file_ext compression_get_list
compression_is_supported compression_get_property
compression_guess_from_filename);
=head1 NAME
Dpkg::Compression - simple database of available compression methods
=head1 DESCRIPTION
This modules provides a few public funcions and a public regex to
interact with the set of supported compression methods.
=head1 EXPORTED VARIABLES
=over 4
=cut
my $COMP = {
"gzip" => {
"file_ext" => "gz",
"comp_prog" => "gzip",
"decomp_prog" => "gunzip",
},
"bzip2" => {
"file_ext" => "bz2",
"comp_prog" => "bzip2",
"decomp_prog" => "bunzip2",
},
"lzma" => {
"file_ext" => "lzma",
"comp_prog" => "lzma",
"decomp_prog" => "unlzma",
},
"xz" => {
"file_ext" => "xz",
"comp_prog" => "xz",
"decomp_prog" => "unxz",
},
};
=item $compression_re_file_ext
A regex that matches a file extension of a file compressed with one of the
supported compression methods.
=back
=cut
my $regex = join "|", map { $_->{"file_ext"} } values %$COMP;
our $compression_re_file_ext = qr/(?:$regex)/;
=head1 EXPORTED FUNCTIONS
=over 4
=item my @list = compression_get_list()
Returns a list of supported compression methods (sorted alphabetically).
=cut
sub compression_get_list {
return sort keys %$COMP;
}
=item compression_is_supported($comp)
Returns a boolean indicating whether the give compression method is
known and supported.
=cut
sub compression_is_supported {
return exists $COMP->{$_[0]};
}
=item compression_get_property($comp, $property)
Returns the requested property of the compression method. Returns undef if
either the property or the compression method doesn't exist. Valid
properties currently include "file_ext" for the file extension,
"comp_prog" for the name of the compression program and "decomp_prog" for
the name of the decompression program.
=cut
sub compression_get_property {
my ($comp, $property) = @_;
return undef unless compression_is_supported($comp);
return $COMP->{$comp}{$property} if exists $COMP->{$comp}{$property};
return undef;
}
=item compression_guess_from_filename($filename)
Returns the compression method that is likely used on the indicated
filename based on its file extension.
=cut
sub compression_guess_from_filename {
my $filename = shift;
foreach my $comp (compression_get_list()) {
my $ext = compression_get_property($comp, "file_ext");
if ($filename =~ /^(.*)\.\Q$ext\E$/) {
return $comp;
}
}
return undef;
}
=back
=head1 AUTHOR
Raphaël Hertzog <hertzog@debian.org>.
=cut
1;
|
