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.
21
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.
24
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.
32

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 $file based on the filename and
56           filename extensions.  Returns undef on failure. The file doesn't
57           need to exist.
58
59           Behaviour in list context (wantarray) is unspecified and will
60           change in future releases.
61
62       "default($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 $File::MimeInfo::LANG
82           to specify a language.
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84           This method returns undef when no xml file was found (i.e. the
85           mimetype doesn't exist in the database). It returns an empty string
86           when the xml file doesn't contain a description in the language you
87           specified.
88
89           Currently no real xml parsing is done, it trusts the xml files are
90           nicely formatted.
91
92       "mimetype_canon($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       "has_mimeinfo_database()"
112           Check if there are mimeinfo database files available; returns 1 on
113           success.  If you don't have the shared-mime-info package installed
114           or not in the PATH or @File::MimeInfo::DIRS does not contain
115           database directories, you will not get the successful reply.
116
117           New in version 0.30.
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119       "rehash()"
120           Rehash the data files. Glob information is preparsed when this
121           method is called.
122
123           If you want to by-pass the XDG basedir system you can specify your
124           database directories by setting @File::MimeInfo::DIRS. But normally
125           it is better to change the XDG basedir environment variables.
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127       "rehash_aliases()"
128           Rehashes the mime/aliases files.
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130       "rehash_subclasses()"
131           Rehashes the mime/subclasses files.
132

DIAGNOSTICS

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

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

148       Perl versions prior to 5.8.0 do not have the ':utf8' IO Layer, thus for
149       the default method and for reading the xml files utf8 is not supported
150       for these versions.
151
152       Since it is not possible to distinguish between encoding types (utf8,
153       latin1, latin2 etc.)  in a straightforward manner only utf8 is
154       supported (because the spec recommends this).
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156       This module does not yet check extended attributes for a mimetype.
157       Patches for this are very welcome.
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159       This module uses the FreeDesktop.org shared mime info database. On your
160       desktop linux this is typically pre-installed so it's not a problem. On
161       your server you can install the shared-mime-info package via apt or dnf
162       or apk or whatnot.
163
164       To install on macOS, you can install it like this:
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166           brew install shared-mime-info
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AUTHOR

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

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