MIME Encapsulation of Macintosh Files - MacMIME

Network Working Group                                   Patrik Faltstrom
Request for Comments: 1740                 Royal Institute of Technology
Category: Standards Track                                   Dave Crocker
                                                  Brandenburg Consulting
                                                            Erik E. Fair
                                                     Apple Computer Inc.
                                                           December 1994


            MIME Encapsulation of Macintosh files - MacMIME

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Abstract

   This memo describes the format to use when sending Apple Macintosh
   files via MIME [BORE93].  The format is compatible with existing
   mechanisms for distributing Macintosh files, while allowing non-
   Macintosh systems access to data in standardized formats.

2.  Introduction

   Files on the Macintosh consists of two parts, called forks:

   Data fork:       The actual data included in the file.  The Data
                    fork is typically the only meaningful part of a
                    Macintosh file on a non-Macintosh computer system.
                    For example, if a Macintosh user wants to send a
                    file of data to a user on an IBM-PC, she would only
                    send the Data fork.

   Resource fork:   Contains a collection of arbitrary attribute/value
                    pairs, including program segments, icon bitmaps,
                    and parametric values.

   Additional information regarding Macintosh files is stored by the
   Finder in a hidden file, called the "Desktop Database".

   Because of the complications in storing different parts of a
   Macintosh file in a non-Macintosh filesystem that only handles
   consecutive data in one part, it is common to convert the Macintosh
   file into some other format before transferring it over the network.

   The two styles of use are [APPL90]:

   AppleSingle:   Apple's standard format for encoding Macintosh files
                  as one byte stream.
   AppleDouble:   Similar to AppleSingle except that the Data fork is
                  separated from the Macintosh-specific parts by the
                  AppleDouble encoding.

   AppleDouble is the preferred format for a Macintosh file that is to
   be included in an Internet mail message, because it provides
   recipients with Macintosh computers the entire document, including
   Icons and other Macintosh specific information, while other users
   easily can extract the Data fork (the actual data) as it is separated
   from the AppleDouble encoding.

2.  MIME format for Apple/Macintosh-specific file information

   2a.  APPLICATION/APPLEFILE

      MIME type-name:            APPLICATION
      MIME subtype name:         APPLEFILE
      Required parameters:       none
      Optional parameters:       NAME, which must be a "value" as
                                 defined in RFC-1521 [BORE93].
      Encoding considerations:   The presence of binary data will
                                 typically require use of
                                 Content-Transfer-Encoding: BASE64
      Security considerations:   See separate section in the document
      Published specification:   Apple-single & Apple-double [APPL90]
      Rationale:                 Permits MIME-based transmission of
                                 data with Apple/Macintosh specific
                                 information, while allowing general
                                 access to non-specific user data.

   2b.  MULTIPART/APPLEDOUBLE

      MIME type-name:            MULTIPART
      MIME subtype name:         APPLEDOUBLE
      Required parameters:       none
      Optional parameters:       NAME, which must be a "value" as
                                 defined in RFC-1521 [BORE93].
      Encoding considerations:   none
      Security considerations:   See separate section in the document
      Published specification:   Apple-single & Apple-double [APPL90]
      Rationale:                 Permits MIME-based transmission of
                                 data with Apple/Macintosh specific
                                 information, while allowing general
                                 access to non-specific user data.

   2c.  Detail specific to MIME-based usage

      Macintosh documents do not always need to be sent in a special
      format.  Those documents with well-known MIME types and
      non-existent or trivial resource forks can be sent as regular
      MIME body parts, without use of AppleSingle or AppleDouble.

      Documents which lack a data fork must be sent as AppleSingle.

      Unless there are strong reasons not to, all other documents
      should normally be sent as AppleDouble.  This includes documents
      with non-trivial resource forks, and documents without
      corresponding well-known MIME types.

      It may be valuable in some cases to allow the user to choose one
      format over another, either because he disagrees with the
      implementor's definition of "trivial" resource forks, or for
      reasons of his own.

3.  AppleSingle

   An AppleSingle, version 2 file, is sent as one consecutive stream of
   bytes.  The format is described in [APPL90] with a brief summary in
   Appendix A. The one and only part of the file is sent in an
   application/applefile message.

   The first four bytes of an AppleSingle header are, in hexadecimal:
   00, 05, 16, 00.

   The AppleSingle file is binary data.  Hence, it may be necessary to
   perform a Content-Transfer-Encoding for transmission, depending on
   the underlying email transport environment.  The safest encoding is
   Base64, since it permits transfer over the most restricted channels.

   Even though an AppleSingle file includes the original Macintosh
   filename, it is recommended that a name parameter be included on the
   Content-Type header to give the recipient a hint as to what file is
   attached.  The value of the name parameter must be a "value" as
   defined by RFC-1521 [BORE93].  Note that this restricts the value to
    seven-bit US-ASCII characters.

   3a.  AppleSingle example

      Content-Type: application/applefile; name="Computers-1/2-93"

          [The AppleSingle file goes here]

4.  AppleDouble

   An AppleDouble, version 2, file is divided in two parts:

   Header:      including the Macintosh resource fork and desktop
                information and
   Data fork:   containing the Macintosh data fork.

   The AppleDouble format is described in [APPL90] with a brief summary
   in Appendix B.

   The AppleDouble file itself is sent as a multipart/appledouble MIME
   body-part, which may have only two sub-parts.  The header is sent as
   application/applefile and the data fork as whatever best describes
   it.  For example, is the data for is actually a GIF image, it should
   be sent as image/gif.  If no appropriate Content-Type has been
   registered for the data type, it should be sent as an
   application/octet-stream.

   The first four bytes of an AppleDouble header are, in hexadecimal:
   00, 05, 16, 07.

   The AppleDouble header is binary data.  Hence, it may be necessary to
   perform a Content-Transfer-Encoding for transmission, depending on
   the underlying email transport environment.  The safest encoding is
   Base64, since it permits transfer over the most restrictive channels.

   Even though an AppleDouble file includes the original Macintosh
   filename, it is recommended that a name parameter be included on the
   Content-Type header of both the header and data parts of the
   AppleDouble file to give the recipient a hint as to what file is
   attached.  The value of the name parameter must be a "value" as
   defined by RFC-1521 [BORE93].  Note that this restricts the value to
   seven-bit US-ASCII characters.

   4a.  AppleDouble example

      Content-Type: multipart/appledouble; boundary=mac-part

      --mac-part
      Content-Type: application/applefile; name="My-new-car"

          [The AppleDouble header goes here]

      --mac-part
      Content-Type: image/gif;

          [The data fork goes here]

      --mac-part--

5.  References

   BORE93   Borenstein N., and N. Freed, MIME (Multipurpose Internet
            Mail Extensions): Mechanisms for Specifying and Describing
            the Format of Internet Message Bodies, RFC 1521, Bellcore,
            Innosoft, September 1993.

   APPL90   AppleSingle/AppleDouble Formats for Foreign Files
            Developer's Note, Apple Computer, Inc., 1990

6.  Security Considerations

   To the extent that application/applefile facilitates the transmission
   of operating-system sensitive data, it may open a door for easier
   relaxation of security rules than is intended either by the sender of
   the administrator of the sender's system.

7.  Acknowledgements

   Thanks to all of the people on the ietf-822 list who have provided
   much meaningful input for this document.  Some of them must though be
   remembered by name, because they have almost crushed my mailbox with
   a very nice and interesting debate:

      Johan Berglund, Steve Dorner, David Gelhar, David Herron, Lee
      Jones, Raymond Lau, Jamey Maze, John B. Melby, Jan Michael
      Rynning, Rens Troost and Peter Svanberg.

10.  Authors' Addresses

   Patrik Faltstrom
   Department of Numerical Analysis and Computing Science
   Royal Institute of Technology
   S-100 44 Stockholm
   Sweden

   EMail: paf@nada.kth.se


   Dave Crocker
   Brandenburg Consulting
   675 Spruce Dr.
   Sunnyvale, CA  94086

   EMail: dcrocker@mordor.stanford.edu


   Erik E. Fair
   Engineering Computer Operations
   Apple Computer Inc.

   EMail: fair@apple.com

Appendix A.  The AppleSingle format

   In the AppleSingle format, a file's contents and attributes are
   stored in a single file in the foreign file system.  For example,
   both forks of a Macintosh file, the Finder information, and an
   associated comment are arranged in a single file with a simple
   structure.

   An AppleSingle file consists of a header followed by one or more data
   entries.  The header consists of several fixed fields and a list of
   entry descriptors, each pointing to a data entry.  Each entry is
   optional and may or may not appear in the file.

    AppleSingle file header:

   Field               Length

   Magic number         4 bytes
   Version number       4 bytes
   Filler              16 bytes
   Number of entries    2 bytes

    Entry descriptor for each entry:

   Entry ID             4 bytes
   Offset               4 bytes
   Length               4 bytes

   Byte ordering in the file fields follows MC68000 conventions, most
   significant byte first.  The fields in the header file follow the
   conventions described in the following sections.

   Magic number
      This field, modelled after the UNIX magic number feature,
      specifies the file's format.  Apple has defined the magic number
      for the AppleSingle format as $00051600 or 0x00051600.

   Version number
      This field denotes the version of AppleSingle format in the event
      the format evolves (more fields may be added to the header).  The
      version described in this note is version $00020000 or
      0x00020000.

   Filler
      This field is all zeros ($00 or 0x00).

   Number of entries
      This field specifies how many different entries are included in
      the file.  It is an unsigned 16-bit number.  If the number of
      entries is any number other than 0, then that number of entry
      descriptors immediately follows the number of entries field.

   Entry descriptors

      The entry descriptor is made up of the following three fields:

      Entry ID:   an unsigned 32-bit number, defines what the entry is.
                  Entry IDs range from 1 to $FFFFFFFF. Entry ID 0 is
                  invalid.
      Offset:     an unsigned 32-bit number, shows the offset from the
                  beginning of the file to the beginning of the entry's
                  data.
      Length:     an unsigned 32-bit number, shows the length of the
                  data in bytes.  The length can be 0.

   Predefined entry ID's

      Apple has defined a set of entry IDs and their values as follows:

      Data Fork              1 Data fork
      Resource Fork          2 Resource fork
      Real Name              3 File's name as created on home file
                               system
      Comment                4 Standard Macintosh comment
      Icon, B&W              5 Standard Macintosh black and white icon
      Icon, Colour           6 Macintosh colour icon
      File Dates Info        8 File creation date, modification date,
                               and so on
      Finder Info            9 Standard Macintosh Finder information
      Macintosh File Info   10 Macintosh file information, attributes
                               and so on
      ProDOS File Info      11 ProDOS file information, attributes and
                               so on
      MS-DOS File Info      12 MS-DOS file information, attributes and
                               so on
      Short Name            13 AFP short name
      AFP File Info         14 AFP file, information, attributes and so
                               on
      Directory ID          15 AFP directory ID

      Apple reserves the range of entry IDs from 1 to $7FFFFFFF. The
      rest of the range is available for applications to define their
      own entries.  Apple does not arbitrate the use of the rest of the
      range.

Appendix B.  The AppleDouble format

   The AppleDouble format uses two files to store data, resources and
   attributes.  The AppleDouble Data file contains the data fork and the
   AppleDouble Header file contains the resource fork.

   The AppleDouble Data file contains the standard Macintosh data fork
   with no additional header.  The AppleDouble Header file has exactly
   the same format as the AppleSingle file, except that it does not
   contain a Data fork entry.  The magic number in the AppleDouble
   Header file differs from the magic number in the AppleSingle Header
   file so that an application can tell whether it needs to look in
   another file for the data fork.  The magic number for the AppleDouble
   format is $00051607 or 0x00051607.

   The entries in the AppleDouble Header file can appear in any order;
   however, since the resource fork is the entry that is most commonly
   extended (after the data fork), Apple recommends that the resource
   fork entry to be placed last in the file.  The data fork is easily
   extended because it resides by itself in the AppleDouble Data file.

Appendix C.  applefile.h

   This is an example of a header file for the language C which can be
   used when parsing the data in either an AppleSingle file or
   AppleDouble header.

   The file is written by Lee Jones.  Distribution is unlimited.

   /* applefile.h - Data structures used by AppleSingle/AppleDouble
    * file format
    *
    * Written by Lee Jones, 22-Oct-1993
    *
    * For definitive information, see "AppleSingle/AppleDouble
    * Formats for Foreign Files Developer's Note"; Apple Computer
    * Inc.; (c) 1990.
    *
    * Other details were added from:
    *   Inside Macintosh [old version], volumes II to VI,
    *   Apple include files supplied with Think C 5.0.1,
    *   Microsoft MS-DOS Programmer's Reference, version 5, and
    *   Microsoft C 6.00a's dos.h include file.
    *
    * I don't have ProDOS or AFP Server documentation so related
    * entries may be a bit skimpy.
    *
    * Edit history:
    *
    * when       who  why
    * ---------  ---  ------------------------------------------
    * 22-Oct-93  LMJ  Pull together from Inside Macintosh,
    *                 Developer's Note, etc
    * 26-Oct-93  LMJ  Finish writing first version and list
    *                 references
    * 06-Feb-94  EEF  Very minor cleanup
    */

   /* Following items define machine specific size (for porting). */

   typedef char            xchar8;         /* 8-bit field */
   typedef char            schar8;         /* signed 8-bit field */
   typedef unsigned char   uchar8;         /* unsigned 8-bit field */
   typedef short           xint16;         /* 16-bit field */
   typedef unsigned short  uint16;         /* unsigned 16-bit field */
   typedef long            xint32;         /* 32-bit field */
   typedef long            sint32;         /* signed 32-bit field */
   typedef unsigned long   uint32;         /* unsigned 32-bit field */

   /* REMINDER: the Motorola 680x0 is a big-endian architecture! */

   typedef uint32 OSType;                  /* 32 bit field */

   /* In the QuickDraw coordinate plane, each coordinate is
    * -32767..32767. Each point is at the intersection of a
    * horizontal grid line and a vertical grid line.  Horizontal
    * coordinates increase from left to right. Vertical
    * coordinates increase from top to bottom. This is the way
    * both a TV screen and page of English text are scanned:
    * from top left to bottom right.
    */

   struct Point /* spot in QuickDraw 2-D grid */
   {
       xint16 v; /* vertical coordinate */
       xint16 h; /* horizontal coordinate */
   }; /* Point */

   typedef struct Point Point;

   /* See older Inside Macintosh, Volume II page 84 or Volume IV
    * page 104.
    */

   struct FInfo /* Finder information */
   {
       OSType fdType; /* File type, 4 ASCII chars */
       OSType fdCreator; /* File's creator, 4 ASCII chars */
       uint16 fdFlags; /* Finder flag bits */
       Point  fdLocation; /* file's location in folder */
       xint16 fdFldr; /* file 's folder (aka window) */
   }; /* FInfo */

   typedef struct FInfo FInfo;

   /*
    * Masks for finder flag bits (field fdFlags in struct
    * FInfo).
    */

   #define F_fOnDesk       0x0001 /* file is on desktop (HFS only) */
   #define F_maskColor     0x000E /* color coding (3 bits) */
   /*                      0x0010 /* reserved (System 7) */
   #define F_fSwitchLaunch 0x0020 /* reserved (System 7) */
   #define F_fShared       0x0040 /* appl available to multiple users */
   #define F_fNoINITs      0x0080 /* file contains no INIT resources */
   #define F_fBeenInited   0x0100 /* Finder has loaded bundle res. */
   /*                      0x0200  /* reserved (System 7) */
   #define F_fCustomIcom   0x0400 /* file contains custom icon */
   #define F_fStationary   0x0800 /* file is a stationary pad */
   #define F_fNameLocked   0x1000 /* file can't be renamed by Finder */
   #define F_fHasBundle    0x2000 /* file has a bundle */
   #define F_fInvisible    0x4000 /* file's icon is invisible */
   #define F_fAlias        0x8000 /* file is an alias file (System 7) */

   /* See older Inside Macintosh, Volume IV, page 105.
    */

   struct FXInfo /* Extended finder information */

   {
       xint16 fdIconID; /* icon ID number */
       xint16 fdUnused[3]; /* spare */
       schar8 fdScript; /* scrip flag and code */
       schar8 fdXFlags; /* reserved */
       xint16 fdComment; /* comment ID number */
       xint32 fdPutAway; /* home directory ID */
   }; /* FXInfo */

   typedef struct FXInfo FXInfo;

   /* Pieces used by AppleSingle & AppleDouble (defined later). */

   struct ASHeader /* header portion of AppleSingle */
   {
               /* AppleSingle = 0x00051600; AppleDouble = 0x00051607 */

       uint32 magicNum; /* internal file type tag */
       uint32 versionNum; /* format version: 2 = 0x00020000 */
       uchar8 filler[16]; /* filler, currently all bits 0 */
       uint16 numEntries; /* number of entries which follow */
   }; /* ASHeader */

   typedef struct ASHeader ASHeader;

   struct ASEntry /* one AppleSingle entry descriptor */
   {
       uint32 entryID; /* entry type: see list, 0 invalid */
       uint32 entryOffset; /* offset, in octets, from beginning */
                                   /* of file to this entry's data */
       uint32 entryLength; /* length of data in octets */
   }; /* ASEntry */

   typedef struct ASEntry ASEntry;

   /* Apple reserves the range of entry IDs from 1 to 0x7FFFFFFF.
    * Entry ID 0 is invalid.  The rest of the range is available
    * for applications to define their own entry types.  "Apple does
    * not arbitrate the use of the rest of the range."
    */

   #define AS_DATA         1 /* data fork */
   #define AS_RESOURCE     2 /* resource fork */
   #define AS_REALNAME     3 /* File's name on home file system */
   #define AS_COMMENT      4 /* standard Mac comment */
   #define AS_ICONBW       5 /* Mac black & white icon */
   #define AS_ICONCOLOR    6 /* Mac color icon */
           /*              7       /* not used */
   #define AS_FILEDATES    8 /* file dates; create, modify, etc */
   #define AS_FINDERINFO   9 /* Mac Finder info & extended info */
   #define AS_MACINFO      10 /* Mac file info, attributes, etc */
   #define AS_PRODOSINFO   11 /* Pro-DOS file info, attrib., etc */
   #define AS_MSDOSINFO    12 /* MS-DOS file info, attributes, etc */
   #define AS_AFPNAME      13 /* Short name on AFP server */
   #define AS_AFPINFO      14 /* AFP file info, attrib., etc */

   #define AS_AFPDIRID     15 /* AFP directory ID */

   /* matrix of entry types and their usage:
    *
    *                   Macintosh    Pro-DOS    MS-DOS    AFP server
    *                   ---------    -------    ------    ----------
    *  1   AS_DATA         xxx         xxx       xxx         xxx
    *  2   AS_RESOURCE     xxx         xxx
    *  3   AS_REALNAME     xxx         xxx       xxx         xxx
    *
    *  4   AS_COMMENT      xxx
    *  5   AS_ICONBW       xxx
    *  6   AS_ICONCOLOR    xxx
    *
    *  8   AS_FILEDATES    xxx         xxx       xxx         xxx
    *  9   AS_FINDERINFO   xxx
    * 10   AS_MACINFO      xxx
    *
    * 11   AS_PRODOSINFO               xxx
    * 12   AS_MSDOSINFO                          xxx
    *
    * 13   AS_AFPNAME                                        xxx
    * 14   AS_AFPINFO                                        xxx
    * 15   AS_AFPDIRID                                       xxx
    */

   /* entry ID 1, data fork of file - arbitrary length octet string */

   /* entry ID 2, resource fork - arbitrary length opaque octet string;
    *              as created and managed by Mac O.S. resoure manager
    */

   /* entry ID 3, file's name as created on home file system - arbitrary
    *              length octet string; usually short, printable ASCII
    */

   /* entry ID 4, standard Macintosh comment - arbitrary length octet
    *              string; printable ASCII, claimed 200 chars or less
    */

   /* This is probably a simple duplicate of the 128 octet bitmap
    * stored as the 'ICON' resource or the icon element from an 'ICN#'
    * resource.
    */

   struct ASIconBW /* entry ID 5, standard Mac black and white icon */
   {
       uint32 bitrow[32]; /* 32 rows of 32 1-bit pixels */
   }; /* ASIconBW */

   typedef struct ASIconBW ASIconBW;

   /* entry ID 6, "standard" Macintosh color icon - several competing
    *              color icons are defined.  Given the copyright dates
    * of the Inside Macintosh volumes, the 'cicn' resource predominated
    * when the AppleSingle Developer's Note was written (most probable
    * candidate).  See Inside Macintosh, Volume V, pages 64 & 80-81 for
    * a description of 'cicn' resources.
    *
    * With System 7, Apple introduced icon families.  They consist of:
    *      large (32x32) B&W icon, 1-bit/pixel,    type 'ICN#',
    *      small (16x16) B&W icon, 1-bit/pixel,    type 'ics#',
    *      large (32x32) color icon, 4-bits/pixel, type 'icl4',
    *      small (16x16) color icon, 4-bits/pixel, type 'ics4',
    *      large (32x32) color icon, 8-bits/pixel, type 'icl8', and
    *      small (16x16) color icon, 8-bits/pixel, type 'ics8'.
    * If entry ID 6 is one of these, take your pick.  See Inside
    * Macintosh, Volume VI, pages 2-18 to 2-22 and 9-9 to 9-13, for
    * descriptions.
    */

   /* entry ID 7, not used */

   /* Times are stored as a "signed number of seconds before of after
    * 12:00 a.m. (midnight), January 1, 2000 Greenwich Mean Time (GMT).
    * Applications must convert to their native date and time
    * conventions." Any unknown entries are set to 0x80000000
    * (earliest reasonable time).
    */

   struct ASFileDates      /* entry ID 8, file dates info */
   {
       sint32 create; /* file creation date/time */
       sint32 modify; /* last modification date/time */
       sint32 backup; /* last backup date/time */
       sint32 access; /* last access date/time */
   }; /* ASFileDates */

   typedef struct ASFileDates ASFileDates;

   /* See older Inside Macintosh, Volume II, page 115 for
    * PBGetFileInfo(), and Volume IV, page 155, for PBGetCatInfo().
    */

   /* entry ID 9, Macintosh Finder info & extended info */
   struct ASFinderInfo
   {
       FInfo ioFlFndrInfo; /* PBGetFileInfo() or PBGetCatInfo() */
       FXInfo ioFlXFndrInfo; /* PBGetCatInfo() (HFS only) */
   }; /* ASFinderInfo */

   typedef struct ASFinderInfo ASFinderInfo;

   struct ASMacInfo        /* entry ID 10, Macintosh file information */
   {

       uchar8 filler[3]; /* filler, currently all bits 0 */
       uchar8 ioFlAttrib; /* PBGetFileInfo() or PBGetCatInfo() */
   }; /* ASMacInfo */

   typedef struct ASMacInfo ASMacInfo;

   #define AS_PROTECTED    0x0002 /* protected bit */
   #define AS_LOCKED       0x0001 /* locked bit */

   /* NOTE: ProDOS-16 and GS/OS use entire fields.  ProDOS-8 uses low
    * order half of each item (low byte in access & filetype, low word
    * in auxtype); remainder of each field should be zero filled.
    */

   struct ASProdosInfo     /* entry ID 11, ProDOS file information */
   {
       uint16 access; /* access word */
       uint16 filetype; /* file type of original file */
       uint32 auxtype; /* auxiliary type of the orig file */
   }; /* ASProDosInfo */

   typedef struct ASProdosInfo ASProdosInfo;

   /* MS-DOS file attributes occupy 1 octet; since the Developer Note
    * is unspecific, I've placed them in the low order portion of the
    * field (based on example of other ASMacInfo & ASProdosInfo).
    */

   struct ASMsdosInfo      /* entry ID 12, MS-DOS file information */
   {
       uchar8 filler; /* filler, currently all bits 0 */
       uchar8 attr; /* _dos_getfileattr(), MS-DOS */
                                   /* interrupt 21h function 4300h */
   }; /* ASMsdosInfo */

   typedef struct ASMsdosInfo ASMsdosInfo;

   #define AS_DOS_NORMAL   0x00 /* normal file (all bits clear) */
   #define AS_DOS_READONLY 0x01 /* file is read-only */
   #define AS_DOS_HIDDEN   0x02 /* hidden file (not shown by DIR) */
   #define AS_DOS_SYSTEM   0x04 /* system file (not shown by DIR) */
   #define AS_DOS_VOLID    0x08 /* volume label (only in root dir) */
   #define AS_DOS_SUBDIR   0x10 /* file is a subdirectory */
   #define AS_DOS_ARCHIVE  0x20 /* new or modified (needs backup) */

   /* entry ID 13, short file name on AFP server - arbitrary length
    *              octet string; usualy printable ASCII starting with
    *              '!' (0x21)
    */

   struct ASAfpInfo   /* entry ID 12, AFP server file information */
   {
       uchar8 filler[3]; /* filler, currently all bits 0 */
       uchar8 attr; /* file attributes */
   }; /* ASAfpInfo */

   typedef struct ASAfpInfo ASAfpInfo;

   #define AS_AFP_Invisible    0x01 /* file is invisible */
   #define AS_AFP_MultiUser    0x02 /* simultaneous access allowed */
   #define AS_AFP_System       0x04 /* system file */
   #define AS_AFP_BackupNeeded 0x40 /* new or modified (needs backup) */

   struct ASAfpDirId       /* entry ID 15, AFP server directory ID */
   {
       uint32 dirid; /* file's directory ID on AFP server */
   }; /* ASAfpDirId */

   typedef struct ASAfpDirId ASAfpDirId;

   /*
    * The format of an AppleSingle/AppleDouble header
    */
   struct AppleSingle /* format of disk file */
   {
       ASHeader header; /* AppleSingle header part */
       ASEntry  entry[1]; /* array of entry descriptors */
   /* uchar8  filedata[];          /* followed by rest of file */
   }; /* AppleSingle */

   typedef struct AppleSingle AppleSingle;

   /*
    * FINAL REMINDER: the Motorola 680x0 is a big-endian architecture!
    */

   /* End of applefile.h */