class MimeMagic

Mime type detection

Generated from freedesktop.org.xml

Constants

VERSION: MimeMagic version string @api public

Attributes

mediatype[R]

subtype[R]

type[R]

Public Class Methods

add(type, options) click to toggle source

Add custom mime type. Arguments:

type: Mime type
options: Options hash

Option keys:

:extensions: String list or single string of file extensions
:parents: String list or single string of parent mime types
:magic: Mime magic specification
:comment: Comment string

# File lib/mimemagic.rb, line 23
def self.add(type, options)
  extensions = [options[:extensions]].flatten.compact
  TYPES[type] = [extensions,
                [options[:parents]].flatten.compact,
                options[:comment]]
  extensions.each {|ext| EXTENSIONS[ext] = type }
  MAGIC.unshift [type, options[:magic]] if options[:magic]
end

by_extension(ext) click to toggle source

Lookup mime type by file extension

# File lib/mimemagic.rb, line 65
def self.by_extension(ext)
  ext = ext.to_s.downcase
  mime = ext[0..0] == '.' ? EXTENSIONS[ext[1..-1]] : EXTENSIONS[ext]
  mime && new(mime)
end

by_magic(io) click to toggle source

Lookup mime type by magic content analysis. This is a slow operation.

# File lib/mimemagic.rb, line 78
def self.by_magic(io)
  mime =
    unless io.respond_to?(:seek) && io.respond_to?(:read)
      str = io.respond_to?(:read) ? io.read : io.to_s
      str = str.force_encoding(Encoding::BINARY) if str.respond_to? :force_encoding
      MAGIC.find {|type, matches| magic_match_str(str, matches) }
    else
      io.binmode
      io.set_encoding(Encoding::BINARY) if io.respond_to?(:set_encoding)
      MAGIC.find {|type, matches| magic_match_io(io, matches) }
    end
  mime && new(mime[0])
end

by_path(path) click to toggle source

Lookup mime type by filename

# File lib/mimemagic.rb, line 72
def self.by_path(path)
  by_extension(File.extname(path))
end

child?(child, parent) click to toggle source

# File lib/mimemagic.rb, line 108
def self.child?(child, parent)
  child == parent || TYPES.key?(child) && TYPES[child][1].any? {|p| child?(p, parent) }
end

new(type) click to toggle source

Mime type by type string

# File lib/mimemagic.rb, line 9
def initialize(type)
  @type = type
  @mediatype, @subtype = type.split('/', 2)
end

remove(type) click to toggle source

Removes a mime type from the dictionary. You might want to do this if you're seeing impossible conflicts (for instance, application/x-gmc-link).

type: The mime type to remove. All associated extensions and magic are removed too.

# File lib/mimemagic.rb, line 35
def self.remove(type)
  EXTENSIONS.delete_if {|ext, t| t == type }
  MAGIC.delete_if {|t, m| t == type }
  TYPES.delete(type)
end

Private Class Methods

magic_match_io(io, matches) click to toggle source

# File lib/mimemagic.rb, line 112
def self.magic_match_io(io, matches)
  matches.any? do |offset, value, children|
    match =
      if Range === offset
        io.seek(offset.begin)
        x = io.read(offset.end - offset.begin + value.bytesize)
        x && x.include?(value)
      else
        io.seek(offset)
        io.read(value.bytesize) == value
      end
    match && (!children || magic_match_io(io, children))
  end
end

magic_match_str(str, matches) click to toggle source

# File lib/mimemagic.rb, line 127
def self.magic_match_str(str, matches)
  matches.any? do |offset, value, children|
    match =
      if Range === offset
        x = str[offset.begin, offset.end - offset.begin + value.bytesize]
        x && x.include?(value)
      else
        str[offset, value.bytesize] == value
      end
    match && (!children || magic_match_str(str, children))
  end
end

Public Instance Methods

==(other)

Alias for: eql?

audio?() click to toggle source

# File lib/mimemagic.rb, line 46
def audio?; mediatype == 'audio'; end

child_of?(parent) click to toggle source

Returns true if type is child of parent type

# File lib/mimemagic.rb, line 50
def child_of?(parent)
  MimeMagic.child?(type, parent)
end

comment() click to toggle source

Get mime comment

# File lib/mimemagic.rb, line 60
def comment
  (TYPES.key?(type) ? TYPES[type][2] : nil).to_s
end

eql?(other) click to toggle source

Allow comparison with string

# File lib/mimemagic.rb, line 98
def eql?(other)
  type == other.to_s
end

Also aliased as: ==

extensions() click to toggle source

Get string list of file extensions

# File lib/mimemagic.rb, line 55
def extensions
  TYPES.key?(type) ? TYPES[type][0] : []
end

hash() click to toggle source

# File lib/mimemagic.rb, line 102
def hash
  type.hash
end

image?() click to toggle source

Mediatype shortcuts

# File lib/mimemagic.rb, line 45
def image?; mediatype == 'image'; end

text?() click to toggle source

Returns true if type is a text format

# File lib/mimemagic.rb, line 42
def text?; mediatype == 'text' || child_of?('text/plain'); end

to_s() click to toggle source

Return type as string

# File lib/mimemagic.rb, line 93
def to_s
  type
end

video?() click to toggle source

# File lib/mimemagic.rb, line 47
def video?; mediatype == 'video'; end