Class: Magic

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

Overview

:startdoc:

Defined Under Namespace

Classes: Error, FlagsError, LibraryError, MagicError, NotImplementedError

Constant Summary collapse

VERSION =

Current version of Magic.

'0.0.1'
NONE =

No special handling and/or flags specified. Default behaviour.

INT2NUM(MAGIC_NONE)
DEBUG =

Print debugging messages to standard error output.

INT2NUM(MAGIC_DEBUG)
INT2NUM(MAGIC_SYMLINK)
COMPRESS =

If the file is compressed, unpack it and look at the contents.

INT2NUM(MAGIC_COMPRESS)
DEVICES =

If the file is a block or character special device, then open the device and try to look at the contents.

INT2NUM(MAGIC_DEVICES)
MIME_TYPE =

Return a MIME type string, instead of a textual description.

INT2NUM(MAGIC_MIME_TYPE)
CONTINUE =

Return all matches, not just the first.

INT2NUM(MAGIC_CONTINUE)
CHECK =

Check the Magic database for consistency and print warnings to standard error output.

INT2NUM(MAGIC_CHECK)
PRESERVE_ATIME =

Attempt to preserve access time (atime, utime or utimes) of the file queried on systems that support such system calls.

INT2NUM(MAGIC_PRESERVE_ATIME)
RAW =

Do not translate unprintable characters to an octal representation.

INT2NUM(MAGIC_RAW)
ERROR =

Treat operating system errors while trying to open files and follow symbolic links as first class errors, instead of storing them in the Magic library error buffer for retrieval later.

INT2NUM(MAGIC_ERROR)
MIME_ENCODING =

Return a MIME encoding, instead of a textual description.

INT2NUM(MAGIC_MIME_ENCODING)
MIME =

A shorthand for using MIME_TYPE and MIME_ENCODING flags together.

INT2NUM(MAGIC_MIME)
APPLE =

Return the Apple creator and type.

INT2NUM(MAGIC_APPLE)
NO_CHECK_COMPRESS =

Do not look for, or inside compressed files.

INT2NUM(MAGIC_NO_CHECK_COMPRESS)
NO_CHECK_TAR =

Do not look for, or inside tar archive files.

INT2NUM(MAGIC_NO_CHECK_TAR)
NO_CHECK_SOFT =

Do not consult Magic files.

INT2NUM(MAGIC_NO_CHECK_SOFT)
NO_CHECK_APPTYPE =

Check for EMX application type (only supported on EMX).

INT2NUM(MAGIC_NO_CHECK_APPTYPE)
NO_CHECK_ELF =

Do not check for ELF files (do not examine ELF file details).

INT2NUM(MAGIC_NO_CHECK_ELF)
NO_CHECK_TEXT =

Do not check for various types of text files.

INT2NUM(MAGIC_NO_CHECK_TEXT)
NO_CHECK_CDF =

Do not check for CDF files.

INT2NUM(MAGIC_NO_CHECK_CDF)
NO_CHECK_TOKENS =

Do not look for known tokens inside ASCII files.

INT2NUM(MAGIC_NO_CHECK_TOKENS)
NO_CHECK_ENCODING =

Return a MIME encoding, instead of a textual description.

INT2NUM(MAGIC_NO_CHECK_ENCODING)
NO_CHECK_BUILTIN =

Do not use built-in tests; only consult the Magic file.

INT2NUM(MAGIC_NO_CHECK_BUILTIN)
NO_CHECK_ASCII =

Do not check for various types of text files, same as NO_CHECK_TEXT.

INT2NUM(MAGIC_NO_CHECK_ASCII)
NO_CHECK_FORTRAN =

Do not look for Fortran sequences inside ASCII files.

INT2NUM(MAGIC_NO_CHECK_FORTRAN)
NO_CHECK_TROFF =

Do not look for troff sequences inside ASCII files.

INT2NUM(MAGIC_NO_CHECK_TROFF)

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#new ⇒ self #new(path, ...) ⇒ self #new(array) ⇒ self

Opens the underlying Magic database and returns a new Magic.

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>

Will raise Magic::LibraryError exception if, or Magic::MagicError exception if, or

See also: Magic::open, Magic::mime, Magic::type, Magic::encoding, Magic::compile and Magic::check

Overloads:

  • #new ⇒ self
  • #new(path, ...) ⇒ self
  • #new(array) ⇒ self 


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# File 'ext/magic/ruby-magic.c', line 83

VALUE
rb_mgc_initialize(VALUE object, VALUE arguments)
{
    VALUE mutex = Qnil;

    magic_arguments_t ma;
    const char *klass = NULL;

    if (rb_block_given_p()) {
        klass = "Magic";

        if (!NIL_P(object)) {
            klass = rb_class2name(CLASS_OF(object));
        }

        rb_warn("%s::new() does not take block; use %s::open() instead",
                klass, klass);
    }

    mutex = rb_class_new_instance(0, 0, rb_const_get(rb_cObject,
                rb_intern("Mutex")));

    rb_ivar_set(object, id_at_mutex, mutex);

    MAGIC_COOKIE(ma.cookie);

    ma.flags = MAGIC_NONE;
    ma.data.file.path = NULL;

    rb_ivar_set(object, id_at_flags, INT2NUM(ma.flags));
    rb_mgc_load(object, arguments);

    return object;
}

Class Method Details

.check(path) ⇒ Object

call-seq:

Magic.check( path, ... ) -> true or false
Magic.check( array )     -> true or false

Returns

Example:

See also: Magic::open, Magic::mime, Magic::type, Magic::encoding and Magic::compile



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# File 'lib/magic.rb', line 181

def check(path)
  open {|m| m.check(path) }
end

.compile(path) ⇒ Object

call-seq:

Magic.compile( path, ... ) -> true
Magic.compile( array )     -> true

Returns

Example:

See also: Magic::open, Magic::mime, Magic::type, Magic::encoding, and Magic::check



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# File 'lib/magic.rb', line 166

def compile(path)
  open {|m| m.compile(path) }
end

.encoding(&block) ⇒ Object

call-seq:

Magic.encoding                  -> self
Magic.encoding {|magic| block } -> string or array

Returns

Example:

See also: Magic::open, Magic::mime, Magic::type, Magic::compile and Magic::check



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# File 'lib/magic.rb', line 151

def encoding(&block)
  open(Magic::MIME_ENCODING, &block)
end

.mime(&block) ⇒ Object

call-seq:

Magic.mime                  -> self
Magic.mime {|magic| block } -> string or array

Returns

Example:

See also: Magic::open, Magic::type, Magic::encoding, Magic::compile and Magic::check



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# File 'lib/magic.rb', line 121

def mime(&block)
  open(Magic::MIME, &block)
end

.open(flags = Magic::NONE) ⇒ Object

call-seq:

Magic.open( flags )                  -> self
Magic.open( flags ) {|magic| block } -> string or array

Returns

Example:

See also: Magic::mime, Magic::type, Magic::encoding, Magic::compile and Magic::check



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# File 'lib/magic.rb', line 95

def open(flags = Magic::NONE)
  magic = Magic.new
  magic.flags = flags

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

.type(&block) ⇒ Object

call-seq:

Magic.type                  -> self
Magic.type {|magic| block } -> string or array

Returns

Example:

See also: Magic::open, Magic::mime, Magic::encoding, Magic::compile and Magic::check



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

def type(&block)
  open(Magic::MIME_TYPE, &block)
end

.version ⇒ Integer

Returns

Example:

Magic.version   #=> 517

Will raise Magic::NotImplementedError exception if, or

See also: Magic::version_to_a and Magic::version_to_s

Returns:

  • (Integer) 


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# File 'ext/magic/ruby-magic.c', line 540

VALUE
rb_mgc_version(VALUE object)
{
    int rv;
    int local_errno;

    UNUSED(object);

    rv = magic_version_wrapper();
    local_errno = errno;

    if (rv < 0 && local_errno == ENOSYS) {
        MAGIC_GENERIC_ERROR(rb_mgc_eNotImplementedError, ENOSYS,
                error(E_NOT_IMPLEMENTED));
    }

    return INT2NUM(rv);
}

.version_to_a ⇒ Object Also known as: version_array

call-seq:

Magic.version_to_a -> array

Returns

Example:

Magic.version_to_a   #=> [5, 17]

Will raise Magic::NotImplementedError exception if, or

See also: Magic::version_to_s



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# File 'lib/magic/version.rb', line 46

def version_to_a
  [self.version / 100, self.version % 100]
end

.version_to_s ⇒ Object Also known as: version_string

call-seq:

Magic.version_to_s -> string

Returns

Example:

Magic.version_to_s   #=> "5.17"

Will raise Magic::NotImplementedError exception if, or

See also: Magic::version_to_a



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# File 'lib/magic/version.rb', line 64

def version_to_s
  '%d.%02d' % self.version_to_a
end

Instance Method Details

#buffer(string) ⇒ String, Array

Returns

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>

Will raise Magic::LibraryError exception if, or

See also: Magic#file and Magic#descriptor

Returns:



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# File 'ext/magic/ruby-magic.c', line 466

VALUE
rb_mgc_buffer(VALUE object, VALUE value)
{
    magic_arguments_t ma;
    const char *cstring = NULL;

    Check_Type(value, T_STRING);

    CHECK_MAGIC_OPEN(object);
    MAGIC_COOKIE(ma.cookie);

    ma.flags = NUM2INT(rb_mgc_get_flags(object));

    ma.data.buffer.size = RSTRING_LEN(value);
    ma.data.buffer.buffer = RVAL2CSTR(value);

    cstring = (const char *)MAGIC_SYNCHRONIZED(magic_buffer_internal, &ma);
    if (!cstring) {
        MAGIC_LIBRARY_ERROR(ma.cookie);
    }

    return magic_return(CSTR2RVAL(cstring), &ma);
}

#check ⇒ Boolean #check(path, ...) ⇒ Boolean #check(array) ⇒ Boolean

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>

See also: Magic#compile, Magic::compile and Magic::check

Will raise Magic::LibraryError exception if, or

Overloads:

  • #check ⇒ Boolean

    Returns:

    • (Boolean)
  • #check(path, ...) ⇒ Boolean

    Returns:

    • (Boolean)
  • #check(array) ⇒ Boolean

    Returns:

    • (Boolean) 


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# File 'ext/magic/ruby-magic.c', line 376

VALUE
rb_mgc_check(VALUE object, VALUE arguments)
{
    magic_arguments_t ma;
    VALUE value = Qnil;

    CHECK_MAGIC_OPEN(object);
    MAGIC_COOKIE(ma.cookie);

    if (!RARRAY_EMPTY_P(arguments)) {
        value = magic_join(arguments, CSTR2RVAL(":"));
    }
    else {
        value = magic_join(rb_mgc_get_path(object), CSTR2RVAL(":"));
    }

    ma.flags = NUM2INT(rb_mgc_get_flags(object));
    ma.data.file.path = RVAL2CSTR(value);

    if (!MAGIC_SYNCHRONIZED(magic_check_internal, &ma)) {
        return Qfalse;
    }

    return Qtrue;
}

#close ⇒ nil

Closes the underlying Magic database.

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>
magic.close         #=> nil

See also: Magic#closed?

Returns:

  • (nil) 


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# File 'ext/magic/ruby-magic.c', line 131

VALUE
rb_mgc_close(VALUE object)
{
    magic_t cookie;

    MAGIC_COOKIE(cookie);

    if (cookie) {
        MAGIC_SYNCHRONIZED(magic_close_internal, cookie);

        if (DATA_P(object)) {
            DATA_PTR(object) = NULL;
        }
    }

    return Qnil;
}

#closed? ⇒ Boolean

Returns true if the underlying Magic database is open, or false otherwise.

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>
magic.closed?       #=> false
magic.close         #=> nil
magic.closed?       #=> true

See also: Magic#close

Returns:

  • (Boolean) 


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# File 'ext/magic/ruby-magic.c', line 165

VALUE
rb_mgc_closed(VALUE object)
{
    magic_t cookie;

    MAGIC_COOKIE(cookie);

    if (DATA_P(object) && DATA_PTR(object) && cookie) {
        return Qfalse;
    }

    return Qtrue;
}

#compile ⇒ true #compile(path, ...) ⇒ true #compile(array) ⇒ true

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>

See also: Magic#check, Magic::check and Magic::compile

Will raise Magic::LibraryError exception if, or

Overloads:

  • #compile ⇒ true

    Returns:

    • (true)
  • #compile(path, ...) ⇒ true

    Returns:

    • (true)
  • #compile(array) ⇒ true

    Returns:

    • (true) 


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# File 'ext/magic/ruby-magic.c', line 336

VALUE
rb_mgc_compile(VALUE object, VALUE arguments)
{
    magic_arguments_t ma;
    VALUE value = Qnil;

    CHECK_MAGIC_OPEN(object);
    MAGIC_COOKIE(ma.cookie);

    if (!RARRAY_EMPTY_P(arguments)) {
        value = magic_join(arguments, CSTR2RVAL(":"));
    }
    else {
        value = magic_join(rb_mgc_get_path(object), CSTR2RVAL(":"));
    }

    ma.flags = NUM2INT(rb_mgc_get_flags(object));
    ma.data.file.path = RVAL2CSTR(value);

    if (!MAGIC_SYNCHRONIZED(magic_compile_internal, &ma)) {
        MAGIC_LIBRARY_ERROR(ma.cookie);
    }

    return Qtrue;
}

#descriptor(integer) ⇒ String, Array

Returns

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>

Will raise Magic::LibraryError exception if, or

See also: Magic#file and Magic#buffer

Returns:



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# File 'ext/magic/ruby-magic.c', line 504

VALUE
rb_mgc_descriptor(VALUE object, VALUE value)
{
    magic_arguments_t ma;
    const char *cstring = NULL;

    Check_Type(value, T_FIXNUM);

    CHECK_MAGIC_OPEN(object);
    MAGIC_COOKIE(ma.cookie);

    ma.flags = NUM2INT(rb_mgc_get_flags(object));
    ma.data.file.fd = NUM2INT(value);

    cstring = (const char *)MAGIC_SYNCHRONIZED(magic_descriptor_internal, &ma);
    if (!cstring) {
        MAGIC_LIBRARY_ERROR(ma.cookie);
    }

    return magic_return(CSTR2RVAL(cstring), &ma);
}

#file(path) ⇒ String, Array

Returns

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>

Will raise Magic::LibraryError exception if, or

See also: Magic#buffer and Magic#descriptor

Returns:



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# File 'ext/magic/ruby-magic.c', line 416

VALUE
rb_mgc_file(VALUE object, VALUE value)
{
    int rv;
    magic_arguments_t ma;
    const char *cstring = NULL;
    const char *empty = "(null)";

    Check_Type(value, T_STRING);

    CHECK_MAGIC_OPEN(object);
    MAGIC_COOKIE(ma.cookie);

    ma.flags = NUM2INT(rb_mgc_get_flags(object));
    ma.data.file.path = RVAL2CSTR(value);

    cstring = (const char *)MAGIC_SYNCHRONIZED(magic_file_internal, &ma);
    if (!cstring) {
        rv = magic_version_wrapper();

        if (ma.flags & MAGIC_ERROR) {
            MAGIC_LIBRARY_ERROR(ma.cookie);
        }
        else if (rv < 515) {
            (void)magic_errno(ma.cookie);
            cstring = magic_error(ma.cookie);
        }
    }

    assert(cstring != NULL && "Must be a valid pointer to `const char' type");
    assert(strncmp(cstring, empty, strlen(empty)) != 0 && \
            "Empty or invalid result");

    return magic_return(CSTR2RVAL(cstring), &ma);
}

#flags ⇒ Integer

Returns

Example:

magic = Magic.new           #=> #<Magic:0x007f8fdc012e58>
magic.flags                 #=> 0
magic.flags = Magic::MIME   #=> 1040
magic.flags                 #=> 1040

See also: Magic#flags_to_a

Returns:

  • (Integer) 


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# File 'ext/magic/ruby-magic.c', line 226

VALUE
rb_mgc_get_flags(VALUE object)
{
    CHECK_MAGIC_OPEN(object);
    return rb_ivar_get(object, id_at_flags);
}

#flags=(integer) ⇒ Integer

Example:

magic = Magic.new                #=> #<Magic:0x007f8fdc012e58>
magic.flags = Magic::MIME        #=> 1040
magic.flags = Magic::MIME_TYPE   #=> 16

Will raise Magic::FlagsError exception if, or Magic::LibraryError exception if, or Magic::NotImplementedError exception if, or

Returns:

  • (Integer) 


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# File 'ext/magic/ruby-magic.c', line 247

VALUE
rb_mgc_set_flags(VALUE object, VALUE value)
{
    int local_errno;
    magic_t cookie;

    Check_Type(value, T_FIXNUM);

    CHECK_MAGIC_OPEN(object);
    MAGIC_COOKIE(cookie);

    if (magic_setflags_wrapper(cookie, NUM2INT(value)) < 0) {
        local_errno = errno;

        switch (local_errno) {
            case EINVAL:
                MAGIC_GENERIC_ERROR(rb_mgc_eFlagsError, EINVAL,
                        error(E_FLAG_INVALID_VALUE));
                break;
            case ENOSYS:
                MAGIC_GENERIC_ERROR(rb_mgc_eNotImplementedError, ENOSYS,
                        error(E_FLAG_NOT_IMPLEMENTED));
                break;
            default:
                MAGIC_LIBRARY_ERROR(cookie);
                break;
        }
    }

    return rb_ivar_set(object, id_at_flags, value);
}

#flags_to_a(names = false) ⇒ Object Also known as: flags_array

call-seq:

magic.flags_to_a( names ) -> array

Returns an array

Example:

Will raise Magic::LibraryError exception if, or

See also: Magic#flags

Raises:



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# File 'lib/magic.rb', line 63

def flags_to_a(names = false)
  raise LibraryError, "Magic library is not open" if closed?

  n, i = 0, @flags

  flags = []

  return [names ? 'NONE' : 0] if @flags.zero?

  @@flags_map ||= flags_as_map if names

  while i > 0
    n = 2 ** (Math.log(i) / Math.log(2)).to_i
    i = i - n
    flags.insert(0, names ? @@flags_map[n] : n)
  end

  flags
end

#inspect ⇒ Object

call-seq:

magic.inspect -> string

Returns

Example:

magic = Magic.new   #=> #<Magic:0x007fd5258a1108>
magic.inspect       #=> "#<Magic:0x007fd5258a1108 @flags=0, @path=[\"/etc/magic\", \"/usr/share/misc/magic\"]>"



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# File 'lib/magic.rb', line 47

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

#load ⇒ Array #load(path, ...) ⇒ Array #load(array) ⇒ Array

Example:

magic = Magic.new                                   #=> #<Magic:0x007f8fdc012e58>
magic.load                                          #=> ["/etc/magic", "/usr/share/misc/magic"]
magic.load("/usr/share/misc/magic", "/etc/magic")   #=> ["/usr/share/misc/magic", "/etc/magic"]
magic.load                                          #=> ["/etc/magic", "/usr/share/misc/magic"]

Will raise Magic::LibraryError exception if, or

Overloads:

  • #load ⇒ Array

    Returns:

    • (Array)
  • #load(path, ...) ⇒ Array

    Returns:

    • (Array)
  • #load(array) ⇒ Array

    Returns:

    • (Array) 


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# File 'ext/magic/ruby-magic.c', line 294

VALUE
rb_mgc_load(VALUE object, VALUE arguments)
{
    magic_arguments_t ma;
    VALUE value = Qnil;

    CHECK_MAGIC_OPEN(object);
    MAGIC_COOKIE(ma.cookie);

    if (!RARRAY_EMPTY_P(arguments) && !NIL_P(RARRAY_FIRST(arguments))) {
        value = magic_join(arguments, CSTR2RVAL(":"));
        ma.data.file.path = RVAL2CSTR(value);
    }
    else {
        ma.data.file.path = magic_getpath_wrapper();
    }

    ma.flags = NUM2INT(rb_mgc_get_flags(object));

    if (!MAGIC_SYNCHRONIZED(magic_load_internal, &ma)) {
        MAGIC_LIBRARY_ERROR(ma.cookie);
    }

    value = magic_split(CSTR2RVAL(ma.data.file.path), CSTR2RVAL(":"));

    return rb_ivar_set(object, id_at_path, value);
}

#path ⇒ Array

Returns an array

Example:

magic = Magic.new   #=> #<Magic:0x007f8fdc012e58>
magic.path          #=> ["/etc/magic", "/usr/share/misc/magic"]

Will raise Magic::LibraryError exception if

Returns:

  • (Array) 


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# File 'ext/magic/ruby-magic.c', line 192

VALUE
rb_mgc_get_path(VALUE object)
{
    VALUE value = Qnil;
    const char *cstring = NULL;

    CHECK_MAGIC_OPEN(object);

    value = rb_ivar_get(object, id_at_path);
    if (!NIL_P(value) && !RARRAY_EMPTY_P(value) && !getenv("MAGIC")) {
        return value;
    }

    cstring = magic_getpath_wrapper();
    value = magic_split(CSTR2RVAL(cstring), CSTR2RVAL(":"));

    return rb_ivar_set(object, id_at_path, value);
}