|||||||||III US005579517A United States Patent (19) 11) Patent Number: 5,579,517 Reynolds Et Al
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|||||||||III US005579517A United States Patent (19) 11) Patent Number: 5,579,517 Reynolds et al. (45) Date of Patent: Nov. 26, 1996 (54) COMMON NAME SPACE FOR LONG AND 5,313,646 5/1994 Hendricks et al. ..................... 395/600 SHORT FILENAMES 5,359,725 10/1994 Garcia et al. ... ... 395/500 5,371,885 12/1994 Letwin ... ... 395/600 (75) Inventors: Aaron R. Reynolds, Redmond; Dennis E. 2. 2. Ea. 3: R. Adler, Mercer Island; Ralph A. a 4/5 allc. ... Lipe, Woodinville; Ray D. Pedrizetti, 5,421,001 5/1995 Methe ..................................... 395/500 Issaquah; Jeffrey T. Parsons; OTHER PUBLICATIONS Rasipuram V. Arun, both of Redmond, & T. all of Wash. Ray Duncan, "Using long filenames and extended attributes' parts 1 & 2, PC Magazine vol. 9 nos 8 & 9. pp. Assignee: Microsoft Corporation, Redmond, 317 & 305, Apr. 24 & May 15, 1990. (73) Wash. Ray Duncan, "Design Goals and Implementation of the new High Performance File System” Microsoft Systems Journal, Appl. No.: 427,004 vol. 4, No. 5, pp. 1-13, Sep. 1989. (21) a v V 9 Filed: Apr. 24, 1995 Primary Examiner-Thomas G. Black (22) Assistant Examiner-C. Pham Related U.S. Application Data Attorney, Agent, or Firm-Seed and Berry (63) Continuation of Ser. No. 41497, Apr. 1, 1993, abandoned. ' ABSTRACT (51) Int. Cl. ................................. G06F 17/30 An operating system provides a common name space for U.S. Cl 395/616. 395/425: 395/500; both long filenames and short filenames. In this common (52) A1 "395,575,364,246,364/DIG 1364,254; namespace, a long filename and a short filename are pro 66526,366. DiG 2 vided for each file. Each file has a short filename directory Field of Search a 1 3 395/425 600 entry and may have at least one long filename directory entry (58) a - 395500 associated with it. The number of long filename directory entries that are associated with a file depends on the number References Cited of characters in the long filename of the file. The long (56) filename directory entries are configured to minimize com U.S. PATENT DOCUMENTS patibility problems with existing installed program bases. 4,987,531 1/1991 Nishikado et al. ..................... 395/600 5,307,494 4/1994 Yasumatsu et al. .................... 395/600 4 Claims, 8 Drawing Sheets Begin --- Y Provide a 82 1. first 10. Long Filename Sisy". No. - y s ----- 86 Yes --- : 's- is ve. its - his ...106 is - Y------88 . Y. inRemove All Return s notifES --- says- : Remove initial Periods.--90 Yes flas SRG." Shorten Name Period c- To ------- 8 Characters y - - ----- : Translate Any --92 Illegal Short Name : Characters into Y------12 ----- Use Revised Y Name As -boss' truncate Leading 96 ShortName -:NAS Yes. Picar - Estegion - 3 Characters - Ram - Y, Ne-too-- 9 Truncate Long Append"-1" To - Name to Leading Portion 6 Characters Of The Name y - -102 Append"-1" To Namc U.S. Patent Nov. 26, 1996 Sheet 1 of 8 5,579,517 Data CPU Processing 10 System Registers -13 AL -15 i Memory - 16 DevicesI/O 14 O.S. h-17 — Figure 1 U.S. Patent Nov. 26, 1996 Sheet 2 of 8 5,579,517 -20 | Last Long Filename Directory Entry 20 First Long Filename Directory Entry -18 Short Filename Directory Entry Figure 2 U.S. Patent Nov. 26, 1996 Sheet 3 of 8 5,579,517 Offset OOh Filename -22 08h -------------- File Extension -24 OBh - File Attribute -26 0Ch. Reserved |-28 16h ---------- - Time of Last Update so 18h --- Date of Last Update 32 1Ah Beginning Disk Cluster |-34 1Ch . File Size -36 a n 18 Figure 3a U.S. Patent Nov. 26, 1996 Sheet 4 of 8 5,579,517 Offset 00h Oh Signature ---38 Long Filename I-40 OBh File Attributes - 42 0Chl --- - - Flags Field - 43 ODh. ------------- Checksum --44 OEh...... -- Long Filename |-48 1Ah Beginning Disk Cluster 50 1.Ch. Long Filename - 52 20h- n 20 Figure 3b U.S. Patent Nov. 26, 1996 Sheet 5 of 8 5,579,517 Create 54 New File Is a ong Filename Directory Entry Needed Yes Allocate Space for Directory Entries 59 Fill in Directory Entries Figure 4 U.S. Patent Nov. 26, 1996 Sheet 6 of 8 5,579,517 ( been D ------------- Set Hidden Bit 62 Set Beginning in File Disk Cluster Attributes Field Field to 0 64 Set Read Only Bit in File Attributes Field Set System Bit in File Attributes Field Set Volume Label in File Attributes Field "-70 Fill in Signature Byte Field Fill in Checksum Byte Field Figure 5a U.S. Patent Nov. 26, 1996 Sheet 7 of 8 5,579,517 7 6 5 4 3 2 1 O File Attributes 42 Figure 5b Provide a. 78 Short File Name Use Short File 80 Name as Long FileName Figure 6a U.S. Patent Nov. 26, 1996 Sheet 8 of 8 5,579,517 A N Begin Y- --- — 82 -104 Provide a Revised Short Name Collide With Long Filename Another Short Is . 84 L-8 6 -m MM - 'W O6 LongName AYNYes Use Long Name Increment Number Valid Short As Short Name In Name By 1 — --- Y ------88 y v Remove All ? Return Does 108 Spaces From N New Name Long Name ... ... ------- ExceedChar 8 ---------------------------- acterS ? Remove Initial Periods,-90 Trailing Periods And 10 Extra Periods Prior To Shorten N The Last Embedded Sho t 2 Period O morrowwow 8 Characters ... v. - Translate Any -92 Illegal Short Name Characters Into --------------------------- 112 " " Use Revised v . Name As 94. - - 96 ShortName Truncate Leading ------ Long Name Yes | Portion to 6 Characters E;XtenSIOn An "...Y. and Extension to 3 Characters - VN-1 00 V 98 Truncate Long Append "-1" To Name to Leading Portion 6 Characters Of The Name - - Append "~1" y To Name Figure 6b 5,579,517 1. 2 COMMON NAME SPACE FOR LONG AND entry includes the second filename for the file. The second SHORT FILENAMES filename includes more characters than the short filename. The data processing system also includes a processor for running the operating system and accessing either the first CROSS-REFERENCE TO RELATED directory entry or the second directory entry to locate the APPLICATION file. This application is a continuation of U.S. patent applica In accordance with yet another aspect of the present tion Ser. No. 08/041,497, filed Apr. 1, 1993, now abandoned. invention, a method is practiced in a data processing system having memory. In accordance with this method, a file is TECHNICAL FIELD 10 created and the file is assigned a user-specified long file name. The long filename is manipulated with the data The present invention relates generally to data processing processing system to create a short filename of fewer systems and, more particularly, to a common name space for characters. The long filename and the short filename are long and short filenames. stored in memory so that the file can be accessed by either 15 the long filename or the short filename. BACKGROUND OF THE INVENTION In accordance with a further aspect of the present inven tion, a method is practiced in which a first directory entry for Many operating systems, such as the MS-DOS, version 5, a file is stored in a memory means. The first directory entry operating system, sold by Microsoft Corporation of Red holds the short filename for the file. The short filename mond, Washington, support only short filenames. In the includes at most a maximum number of characters that is MS-DOS, version 5, operating system, filenames may be a 20 permissible by an application program. A second directory maximum length of eleven characters. Each filename may entry is also stored in the memory means for the file. A have a main portion of eight characters followed by an second directory entry holds at least the first portion of a extension of three characters. An example filename in the long filename for the file. The long filename includes a MS-DOS, version 5, operating system is “EXAMPLE 1. greater number of characters than the maximum number of EXE', wherein “EXAMPLE1' constitutes the main portion 25 characters that is permissible by the application program. and "EXE' constitutes the extension. The application program is run on a processor of the data Each filename is limited to eleven characters due to processing system. The application program identifies the constraints in the file system of the MS-DOS, version 5, file by the short filename. operating system. This file system employs a directory In accordance with a still further aspect of the present structure in which each file has a directory entry associated 30 invention, a method is practiced in which a first directory with it. Unfortunately, the directory entry for a file only entry is stored in the memory means for a file. The first supports filenames with a maximum length of eleven char directory entry holds a short filename for the file that acters. Such a limit in the length of the filenames is often includes at most the maximum number of characters that is frustrating to a user. The length limit of eleven characters permissible by the operating system. A second directory prevents a user from employing adequately descriptive 35 entry is stored in the memory means for the file. The second filenames and, in many instances, forces a user to insert directory entry holds along filename for the file that includes awkward abbreviations of descriptive terms into the file more than the maximum number of characters that is per ale. missible by the operating system. In this instance, the 40 operating system does not use long filenames; rather, it uses SUMMARY OF THE INVENTION solely short filenames.