File::MimeInfo(3pm)

1File::MimeInfo(3)     User Contributed Perl Documentation    File::MimeInfo(3)
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NAME

6       File::MimeInfo - Determine file type from the file name
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SYNOPSIS

9         use File::MimeInfo;
10         my $mime_type = mimetype($file);
11         my $mime_type2 = mimetype('test.png');
12

DESCRIPTION

14       This module can be used to determine the mime type of a file. It tries
15       to implement the freedesktop specification for a shared MIME database.
16
17       For this module shared-mime-info-spec 0.13 was used.
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19       This package only uses the globs file. No real magic checking is used.
20       The File::MimeInfo::Magic package is provided for magic typing.
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22       If you want to determine the mimetype of data in a memory buffer you
23       should use File::MimeInfo::Magic in combination with IO::Scalar.
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25       This module loads the various data files when needed. If you want to
26       hash data earlier see the "rehash" methods below.
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EXPORT

29       The method "mimetype" is exported by default.  The methods "inodetype",
30       "globs", "extensions", "describe", "mimetype_canon" and "mimetype_isa"
31       can be exported on demand.
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METHODS

34       "new()"
35           Simple constructor to allow Object Oriented use of this module.  If
36           you want to use this, include the package as "use File::MimeInfo
37           ();" to avoid importing sub "mimetype()".
38
39       "mimetype($file)"
40           Returns a mimetype string for $file, returns undef on failure.
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42           This method bundles "inodetype" and "globs".
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44           If these methods are unsuccessful the file is read and the mimetype
45           defaults to 'text/plain' or to 'application/octet-stream' when the
46           first ten chars of the file match ascii control chars (white spaces
47           excluded).  If the file doesn't exist or isn't readable "undef" is
48           returned.
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50       "inodetype($file)"
51           Returns a mimetype in the 'inode' namespace or undef when the file
52           is actually a normal file.
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54       "globs($file)"
55           Returns a mimetype string for $file based on the filename and
56           filename extensions.  Returns undef on failure. The file doesn't
57           need to exist.
58
59           Behaviour in list context (wantarray) is unspecified and will
60           change in future releases.
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62       "default($file)"
63           This method decides whether a file is binary or plain text by
64           looking at the first few bytes in the file. Used to decide between
65           "text/plain" and "application/octet-stream" if all other methods
66           have failed.
67
68           The spec states that we should check for the ascii control chars
69           and let higher bit chars pass to allow utf8. We try to be more
70           intelligent using perl utf8 support.
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72       "extensions($mimetype)"
73           In list context, returns the list of filename extensions that map
74           to the given mimetype.  In scalar context, returns the first
75           extension that is found in the database for this mimetype.
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77       "describe($mimetype, $lang)"
78           Returns a description of this mimetype as supplied by the mime info
79           database.  You can specify a language with the optional parameter
80           $lang, this should be the two letter language code used in the xml
81           files. Also you can set the global variable $File::MimeInfo::LANG
82           to specify a language.
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84           This method returns undef when no xml file was found (i.e. the
85           mimetype doesn't exist in the database). It returns an empty string
86           when the xml file doesn't contain a description in the language you
87           specified.
88
89           Currently no real xml parsing is done, it trusts the xml files are
90           nicely formatted.
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92       "mimetype_canon($mimetype)"
93           Returns the canonical mimetype for a given mimetype.  Deprecated
94           mimetypes are typically aliased to their canonical variants.  This
95           method only checks aliases, doesn't check whether the mimetype
96           exists.
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98           Use this method as a filter when you take a mimetype as input.
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100       "mimetype_isa($mimetype)"
101       "mimetype_isa($mimetype, $mimetype)"
102           When give only one argument this method returns a list with
103           mimetypes that are parent classes for this mimetype.
104
105           When given two arguments returns true if the second mimetype is a
106           parent class of the first one.
107
108           This method checks the subclasses table and applies a few rules for
109           implicit subclasses.
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111       "rehash()"
112           Rehash the data files. Glob information is preparsed when this
113           method is called.
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115           If you want to by-pass the XDG basedir system you can specify your
116           database directories by setting @File::MimeInfo::DIRS. But normally
117           it is better to change the XDG basedir environment variables.
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119       "rehash_aliases()"
120           Rehashes the mime/aliases files.
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122       "rehash_subclasses()"
123           Rehashes the mime/subclasses files.
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DIAGNOSTICS

126       This module throws an exception when it can't find any data files, when
127       it can't open a data file it found for reading or when a subroutine
128       doesn't get enough arguments.  In the first case you either don't have
129       the freedesktop mime info database installed, or your environment
130       variables point to the wrong places, in the second case you have the
131       database installed, but it is broken (the mime info database should
132       logically be world readable).
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TODO

135       Make an option for using some caching mechanism to reduce init time.
136
137       Make "describe()" use real xml parsing ?
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LIMITATIONS

140       Perl versions prior to 5.8.0 do not have the ':utf8' IO Layer, thus for
141       the default method and for reading the xml files utf8 is not supported
142       for these versions.
143
144       Since it is not possible to distinguish between encoding types (utf8,
145       latin1, latin2 etc.)  in a straightforward manner only utf8 is
146       supported (because the spec recommends this).
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148       This module does not yet check extended attributes for a mimetype.
149       Patches for this are very welcome.
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AUTHOR

152       Jaap Karssenberg <pardus@cpan.org> Maintained by Michiel Beijen
153       <michiel.beijen@gmail.com>
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COPYRIGHT

156       Copyright (c) 2003, 2012 Jaap G Karssenberg. All rights reserved.  This
157       program is free software; you can redistribute it and/or modify it
158       under the same terms as Perl itself.
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