Class: FileMagic

Inherits:
Object
  • Object
show all
Defined in:
lib/filemagic.rb,
lib/filemagic/version.rb,
ext/filemagic/filemagic.c

Defined Under Namespace

Modules: Ext, Version Classes: FileMagicError

Constant Summary collapse

DEFAULT_MAGIC = 
__FILE__.sub(/\.rb\z/, '/magic.mgc')
FLAGS_BY_SYM =

Map flag names to their values (:name => Integer).

[
  :none,               # No flags
  :debug,              # Turn on debugging
  :symlink,            # Follow symlinks
  :compress,           # Check inside compressed files
  :devices,            # Look at the contents of devices
  :mime_type,          # Return the MIME type
  :continue,           # Return all matches
  :check,              # Print warnings to stderr
  :preserve_atime,     # Restore access time on exit
  :raw,                # Don't convert unprintable chars
  :error,              # Handle ENOENT etc as real errors
  :mime_encoding,      # Return the MIME encoding
  :mime,               # MAGIC_MIME_TYPE | MAGIC_MIME_ENCODING
  :apple,              # Return the Apple creator/type
  :extension,          # Return a /-separated list of extensions
  :compress_transp,    # Check inside compressed files but not report compression
  :nodesc,             # MAGIC_EXTENSION | MAGIC_MIME | MAGIC_APPLE
  :no_check_compress,  # Don't check for compressed files
  :no_check_tar,       # Don't check for tar files
  :no_check_soft,      # Don't check magic entries
  :no_check_apptype,   # Don't check application type
  :no_check_elf,       # Don't check for elf details
  :no_check_text,      # Don't check for text files
  :no_check_cdf,       # Don't check for cdf files
  :no_check_tokens,    # Don't check tokens
  :no_check_encoding,  # Don't check text encodings
  :no_check_builtin,   # No built-in tests; only consult the magic file

  # Defined for backwards compatibility (renamed)
  :no_check_ascii,     # MAGIC_NO_CHECK_TEXT

  # Defined for backwards compatibility; do nothing
  :no_check_fortran,   # Don't check ascii/fortran
  :no_check_troff      # Don't check ascii/troff
].inject({}) { |flags, flag|
  const = "MAGIC_#{flag.to_s.upcase}"
  flags.update(flag => const_defined?(const) && const_get(const))
}
FLAGS_BY_INT =

Map flag values to their names (Integer => :name).

FLAGS_BY_SYM.invert.update(0 => :none)
SIMPLE_RE =

Extract “simple” MIME type.

%r{([.\w\/-]+)}
VERSION = 
Version.to_s
MAGIC_VERSION = 
rb_str_new2(version)
MAGIC_NONE = 
INT2FIX(MAGIC_NONE)
MAGIC_DEBUG = 
INT2FIX(MAGIC_DEBUG)
INT2FIX(MAGIC_SYMLINK)
MAGIC_COMPRESS = 
INT2FIX(MAGIC_COMPRESS)
MAGIC_DEVICES = 
INT2FIX(MAGIC_DEVICES)
MAGIC_MIME_TYPE = 
INT2FIX(MAGIC_MIME_TYPE)
MAGIC_CONTINUE = 
INT2FIX(MAGIC_CONTINUE)
MAGIC_CHECK = 
INT2FIX(MAGIC_CHECK)
MAGIC_PRESERVE_ATIME = 
INT2FIX(MAGIC_PRESERVE_ATIME)
MAGIC_RAW = 
INT2FIX(MAGIC_RAW)
MAGIC_ERROR = 
INT2FIX(MAGIC_ERROR)
MAGIC_MIME_ENCODING = 
INT2FIX(MAGIC_MIME_ENCODING)
MAGIC_MIME = 
INT2FIX(MAGIC_MIME)
MAGIC_APPLE = 
INT2FIX(MAGIC_APPLE)
MAGIC_EXTENSION = 
INT2FIX(MAGIC_EXTENSION)
MAGIC_COMPRESS_TRANSP = 
INT2FIX(MAGIC_COMPRESS_TRANSP)
MAGIC_NODESC = 
INT2FIX(MAGIC_NODESC)
MAGIC_NO_CHECK_COMPRESS = 
INT2FIX(MAGIC_NO_CHECK_COMPRESS)
MAGIC_NO_CHECK_TAR = 
INT2FIX(MAGIC_NO_CHECK_TAR)
MAGIC_NO_CHECK_SOFT = 
INT2FIX(MAGIC_NO_CHECK_SOFT)
MAGIC_NO_CHECK_APPTYPE = 
INT2FIX(MAGIC_NO_CHECK_APPTYPE)
MAGIC_NO_CHECK_ELF = 
INT2FIX(MAGIC_NO_CHECK_ELF)
MAGIC_NO_CHECK_TEXT = 
INT2FIX(MAGIC_NO_CHECK_TEXT)
MAGIC_NO_CHECK_CDF = 
INT2FIX(MAGIC_NO_CHECK_CDF)
MAGIC_NO_CHECK_TOKENS = 
INT2FIX(MAGIC_NO_CHECK_TOKENS)
MAGIC_NO_CHECK_ENCODING = 
INT2FIX(MAGIC_NO_CHECK_ENCODING)
MAGIC_NO_CHECK_BUILTIN =

defined in b5be901 (2010-01-28, 5.05), but broken until 38e0136 (2013-08-15, 5.15)

INT2FIX(MAGIC_NO_CHECK_BUILTIN)
MAGIC_NO_CHECK_ASCII = 
INT2FIX(MAGIC_NO_CHECK_ASCII)
MAGIC_NO_CHECK_FORTRAN = 
INT2FIX(MAGIC_NO_CHECK_FORTRAN)
MAGIC_NO_CHECK_TROFF = 
INT2FIX(MAGIC_NO_CHECK_TROFF)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object 



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# File 'ext/filemagic/filemagic.c', line 103

static VALUE
rb_magic_init(int argc, VALUE *argv, VALUE self) {
  VALUE flags, options, keys, k, m;
  ID mid;
  int i;

  if (rb_scan_args(argc, argv, "11", &flags, &options) == 1) {
    options = rb_hash_new();
  }

  rb_iv_set(self, "iflags", flags);
  rb_iv_set(self, "closed", Qfalse);
  rb_iv_set(self, "@simplified", Qfalse);

  keys = rb_funcall(options, rb_intern("keys"), 0);

  for (i = 0; i < RARRAY_LEN(keys); i++) {
    k = rb_ary_entry(keys, i);
    m = rb_str_plus(rb_obj_as_string(k), rb_str_new2("="));

    if (rb_respond_to(self, mid = rb_intern(StringValueCStr(m)))) {
      rb_funcall(self, mid, 1, rb_hash_aref(options, k));
    }
    else {
      k = rb_funcall(k, rb_intern("inspect"), 0);
      rb_raise(rb_eArgError, "illegal option: %s", StringValueCStr(k));
    }
  }

  return Qnil;
}

Instance Attribute Details

#simplified=(value) ⇒ Object (writeonly)

Sets the attribute simplified

Parameters:

  • value —

    the value to set the attribute simplified to.



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# File 'lib/filemagic.rb', line 136

def simplified=(value)
  @simplified = value
end

Class Method Details

.clear! ⇒ Object

Clear our instance cache.



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# File 'lib/filemagic.rb', line 84

def clear!
  @fm.each_value(&:close).clear
end

.flags(flags) ⇒ Object

Converts flags to integer



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# File 'ext/filemagic/filemagic.c', line 21

static VALUE
rb_magic_flags(VALUE klass, VALUE flags) {
  VALUE map = rb_const_get(cFileMagic, rb_intern("FLAGS_BY_SYM")), f, g;
  int i = MAGIC_NONE, j;

  if (TYPE(flags) != T_ARRAY) {
    rb_raise(rb_eTypeError,
      "wrong argument type %s (expected Array)",
      rb_obj_classname(flags));
  }

  for (j = 0; j < RARRAY_LEN(flags); j++) {
    f = rb_ary_entry(flags, j);

    switch (TYPE(f)) {
      case T_SYMBOL:
        if (RTEST(g = rb_hash_aref(map, f))) {
          f = g;
          /* fall through */
        }
        else {
          f = rb_funcall(f, rb_intern("inspect"), 0);
          rb_raise(rb_eArgError, "%s: %s",
            NIL_P(g) ? "no such flag" : "flag not available",
            StringValueCStr(f));

          break;
        }
      case T_FIXNUM:
        i |= NUM2INT(f);
        break;
      default:
        rb_raise(rb_eTypeError,
          "wrong argument type %s (expected Fixnum or Symbol)",
          rb_obj_classname(f));
    }
  }

  return INT2FIX(i);
}

.fm(*flags) ⇒ Object

Provide a “magic singleton”.



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# File 'lib/filemagic.rb', line 73

def fm(*flags)
  options = flags.last.is_a?(Hash) ? flags.pop : {}

  if fm = @fm[key = [flags = flags(flags), options]]
    return fm unless fm.closed?
  end

  @fm[key] = new(flags, options)
end

.library_version ⇒ Object

Returns the magic version



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# File 'ext/filemagic/filemagic.c', line 4

static VALUE
rb_magic_version(VALUE klass) {
  char version[8] = "0";
#ifdef HAVE_MAGIC_VERSION
  RB_MAGIC_SET_VERSION(magic_version() / 100, magic_version() % 100)
#endif
  return rb_str_new2(version);
}

.magic_version(default = MAGIC_VERSION) ⇒ Object 



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# File 'lib/filemagic.rb', line 109

def magic_version(default = MAGIC_VERSION)
  default != '0' ? default :
    user_magic_version ||
    auto_magic_version ||
    [default, 'unknown']
end

.mime(*flags, &block) ⇒ Object

Just a short-cut to #open with the mime flag set.



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# File 'lib/filemagic.rb', line 105

def mime(*flags, &block)
  open(:mime, *flags, &block)
end

.new(*args) ⇒ Object

FileMagic.new



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# File 'ext/filemagic/filemagic.c', line 63

static VALUE
rb_magic_new(int argc, VALUE *argv, VALUE klass) {
  VALUE obj, args[2];
  magic_t ms;

  if (rb_block_given_p()) {
    rb_warn(
      "FileMagic.new() does not take a block; use FileMagic.open() instead");
  }

  if (argc > 0 && TYPE(args[1] = argv[argc - 1]) == T_HASH) {
    argc--;
  }
  else {
    args[1] = rb_hash_new();
  }

  args[0] = rb_magic_flags(klass, rb_ary_new4(argc, argv));

  if ((ms = magic_open(NUM2INT(args[0]))) == NULL) {
    rb_raise(rb_FileMagicError,
      "failed to initialize magic cookie (%d)", errno || -1);
  }

  if (magic_load(ms, NULL) == -1) {
    rb_raise(rb_FileMagicError,
      "failed to load database: %s", magic_error(ms));
  }

  obj = Data_Wrap_Struct(klass, 0, rb_magic_free, ms);
  rb_obj_call_init(obj, 2, args);

  return obj;
}

.open(*flags) ⇒ Object

Just like #new, but takes an optional block, in which case #close is called at the end and the value of the block is returned.



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# File 'lib/filemagic.rb', line 90

def open(*flags)
  fm = new(*flags)

  if block_given?
    begin
      yield fm
    ensure
      fm.close
    end
  else
    fm
  end
end

.path ⇒ Object

Returns the magic path



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# File 'ext/filemagic/filemagic.c', line 14

static VALUE
rb_magic_getpath(VALUE klass) {
  const char *path = magic_getpath(NULL, 0);
  return path != NULL ? rb_str_new2(path) : Qnil;
}

Instance Method Details

#buffer ⇒ Object

#check ⇒ Object

#close ⇒ Object

Frees resources allocated



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# File 'ext/filemagic/filemagic.c', line 136

static VALUE
rb_magic_close(VALUE self) {
  magic_t ms;

  if (RTEST(rb_magic_closed_p(self))) {
    return Qnil;
  }

  GetMagicSet(self, ms);
  rb_magic_free(ms);

  /* This keeps rb_magic_free from trying to free closed objects */
  DATA_PTR(self) = NULL;

  rb_iv_set(self, "closed", Qtrue);

  return Qnil;
}

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'ext/filemagic/filemagic.c', line 155

static VALUE
rb_magic_closed_p(VALUE self) {
  return rb_attr_get(self, rb_intern("closed"));
}

#compile ⇒ Object

#descriptor ⇒ Object

#fd(fd) ⇒ Object 



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# File 'lib/filemagic.rb', line 149

def fd(fd)
  descriptor(fd.respond_to?(:fileno) ? fd.fileno : fd)
end

#file ⇒ Object

#flags ⇒ Object

#flags=(flags) ⇒ Object

Set flags on the ms object



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# File 'ext/filemagic/filemagic.c', line 185

static VALUE
rb_magic_setflags(VALUE self, VALUE flags) {
  magic_t ms;

  GetMagicSet(self, ms);

  rb_iv_set(self, "iflags",
    flags = rb_magic_flags(CLASS_OF(self), rb_Array(flags)));

  return INT2FIX(magic_setflags(ms, NUM2INT(flags)));
}

#inspect ⇒ Object 



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# File 'lib/filemagic.rb', line 153

def inspect
  super.insert(-2, closed? ? ' (closed)' : '')
end

#io(io, length = 8, rewind = false) ⇒ Object 



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# File 'lib/filemagic.rb', line 142

def io(io, length = 8, rewind = false)
  pos = io.pos if rewind
  buffer(io.read(length))
ensure
  io.pos = pos if pos
end

#list ⇒ Object

#load ⇒ Object

#simplified? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/filemagic.rb', line 138

def simplified?
  @simplified
end