Abstract:
A method and apparatus for invoking system resources directly from within a mark-up language document. Links referencing a pre-defined system command to be invoked may be embedded within the document. The specific system command may be identified in the link by an alias, such as, for example, a numeric code. By clicking on the link, the system will analyze the contents of the link. If the link calls for invoking a system command, the system will extract the alias, determine the appropriate pre-defined system command referred to by the alias, and execute the system command.

Description:
[0001]    This application is a continuation of and claims priority from application Ser. No. 09/465,081, filed Dec. 16, 1999, the content of which is herein incorporated by reference in its entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to mark-up language documents, and more particularly to techniques for invoking system commands from within a mark-up language document.  
           [0004]    2. Description of Related Art  
           [0005]    Mark-up languages have become exceedingly popular tools for authoring electronic content. Mark-up languages used today include, for example, Standard Generalized Markup Language (SGML), HyperText Markup Language (HTML), eXtensible Markup Language (XML), eXtensible HyperText Markup Language (XHTML), and Synchronized Multimedia Integration Language (SMIL). These languages allow the developer to “mark-up” a document. For example, tags may be inserted within the document to specify how the document, or a portion of the document, should be formatted or displayed. As another example, links may be used to define relationships between the document and other documents and to allow a user to jump from one document to another. Links may also be used to perform various functions including, for example, to create tool bars, to link to a cascading style sheet (rev=stylesheet), a script (rev=script), or a printable version (like a .pdf) of the document (rev=print), and to embed authorship details. Links may also perform a variety of functions, including executing a string of commands such as JavaScript commands.  
           [0006]    When viewed through an application program, such as a web browser or a reading device (discussed herein), links are commonly depicted as underlined text having a blue or red color. In the mark-up language document itself, the link is designated by a link attribute and corresponding language to indicate the resource to which it refers. The link attributes generally include, for example, the following: href (URL for linked resource); id (SGML ID attribute); rel (forward link types); rev (reverse link types); and title (advisory title string). Examples of links within a mark-up language document include:  
           [0007]    1) &lt;A HREF=“http://msn.com”&gt; 
           [0008]    2) &lt;A HREF=“ftp://msn.com”&gt; 
           [0009]    3) &lt;A HREF=“javascript://msn.com”&gt; 
           [0010]    4) &lt;A HREF=“mailto:jdoe@webreference.com”&gt; 
           [0011]    The first link refers to a HyperText Transfer Protocol (HTTP) and provides a Uniform Resource Locator (URL) to which the system should jump. The second link refers to a File Transfer Protocol (FTP) and provides a file the system should retrieve. The third link provides JavaScript that the system should run. The fourth link provides an e-mail address to which the system should send an e-mail message.  
           [0012]    Because of their versatility, mark-up languages are now used in a number of applications. One such application is for authoring web-page content. Another such application that is rapidly gaining recognition is for so-called “electronic books” or “e-books.” E-books are electronic publications (such as books, journals, magazines, etc.) that can be viewed using computer-based display devices. Application programs running on these reading devices display the e-book content. Examples of such reading devices include the “ROCKET EBOOK” by NuvoMedia, Inc. and the “SOFTBOOK READER” by Softbook Press, Inc. Alternatively, these devices may be traditional computing devices such as personal computers.  
           [0013]    E-books are provided in a mark-up language format. As a result, e-book pages may be formatted and linked using the commands available in the mark-up language. For example, e-books may be formatted in a general format in accordance with an Open eBook standard. This standard is set forth in Open eBook Publication Structure 1.0, which can be found at www.openebook.org. This publication is incorporated herein by reference in its entirety.  
           [0014]    One aspect of e-books is that it may be desirable to perform various system commands while viewing an e-book. Consider, for example, a user viewing an e-book from a personal computing environment. The user may wish to adjust the font settings. Present systems are limiting in that the user must take several steps to invoke system commands and operations. To adjust font settings, the user must exit the window for the e-book viewing program, call up the specific commands from the operating system to adjust the font, and then return to the e-book. This may be particularly disruptive where the user is in the middle of reading an e-book. It is therefore desirable to have a system where system commands may be more conveniently accessed and performed without interrupting the user&#39;s activity.  
           [0015]    Certain techniques can be used to perform functions within a mark-up language document. In particular, JavaScript may be directly embedded with a tag within the mark-up language document. The tag may designate the JavaScript such that when a user selects the corresponding link, the JavaScript is executed. However, this technique is limiting in that the JavaScript may only perform limited operations and, more significantly, cannot execute system commands outside of the application program reading the JavaScript. Further, the entire JavaScript command set must be included within the mark-up language document. The negative consequence is that possibly undesirable and even malicious functions may be unknowingly executed. Further, the JavaScript-based approach is limiting in that it may unnecessarily increase the size of the document, especially in documents having a large number of JavaScript links. Many e-book documents already are rather large due to the significant amount of text and graphic content. It is therefore desirable to have a system where pre-defined system commands may be easily identified and executed without requiring increased memory for the document.  
         BRIEF SUMMARY OF THE INVENTION  
         [0016]    The present invention solves many of the aforementioned problems by providing a method of invoking pre-defined system commands directly from a mark-up language document. Links referencing a pre-defined system command to be invoked may be embedded within the document. The specific system command may be identified in the link by an alias, such as, for example, a numeric code. When a user selects the link, the system will analyze the contents of the link. If the link includes an instruction to invoke a system command, the system will extract the corresponding alias, refer to a look-up table to identify the appropriate system command to which the alias refers, and execute the identified system command. The look-up table correlates each alias with a pre-defined system command.  
           [0017]    By using the invoking techniques of the present invention, system commands may be invoked directly from within a mark-up language document. Further, since only those system commands identified in the look-up table can be performed, undesirable or harmful system commands are precluded from being invoked. Even further, desired functionality may be provided in mark-up language documents without the need to enter script in the document itself. Even further, system commands may be subsequently added, altered, disabled, or removed from the look-up table and the change can thereby be applied to all pre-existing documents. These as well as other novel advantages, details, embodiments, features and objects of the present invention will be apparent to those skilled in the art from following the detailed description of the invention, the attached claims and accompanying drawings, listed herein, which are useful in explaining the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    In the following text and drawings, wherein similar reference numerals denote similar elements throughout the several views thereof, the present invention is explained with reference to illustrative embodiments, in which:  
         [0019]    [0019]FIG. 1 is a schematic block diagram of a computing device for use with the present invention;  
         [0020]    [0020]FIG. 2 is a schematic block diagram of a reading device in accordance with a preferred embodiment of the present invention;  
         [0021]    [0021]FIG. 3 is an illustrative table identifying various aliases and the corresponding pre-defined system commands in accordance with the present invention;  
         [0022]    [0022]FIG. 4 is an illustration of the present invention implemented within a reading device for reading e-books;  
         [0023]    [0023]FIG. 5 is a screen print of a page of an e-book having small fonts;  
         [0024]    [0024]FIG. 6 is a screen print of a page of an e-book having large fonts; and  
         [0025]    [0025]FIG. 7 is a flow chart depicting the process by which a system command may be invoked in accordance with a preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    In a preferred embodiment, the present invention is implemented within electronic books (“e-books”) and/or programs and devices for reading e-books. However, the invention may be implemented within, and therefore encompasses, any mark-up language document and any system that interacts with mark-up language documents. The electronic reading device for use with the present invention may be a separate hand-held computing device or may be an application for use with a more general computing device such as a personal computer (FIG. 1). Hand-held reading devices available today include, for example, Windows CE devices.  
         [0027]    [0027]FIG. 1 is a schematic block diagram depicting a personal computing device for use with the present invention. It is envisioned that the hand-held reading device would be a simplified version of personal computer  100 . The personal computing device is typically a general-purpose-computing device in the form of a conventional personal computer  100 , including a processing unit  110 , a system memory  120 , and a system bus  130  that couples various system components including the system memory to the processing unit  110 . The system bus  130  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read only memory (ROM)  140  and random access memory (RAM)  150 .  
         [0028]    A basic input/output system  160  (BIOS), containing the basic routines that help to transfer information between elements within the personal computer  100 , such as during start-up, is stored in ROM  140 . The personal computer  100  further includes a hard disk drive  170  for reading from and writing to a hard disk, not shown, a magnetic disk drive  180  for reading from or writing to a removable magnetic disk  190 , and an optical disk drive  191  for reading from or writing to a removable optical disk  192  such as a CD ROM or other optical media. The hard disk drive  170 , magnetic disk drive  180 , and optical disk drive  191  are connected to the system bus  130  by a hard disk drive interface  192 , a magnetic disk drive interface  193 , and an optical disk drive interface  194 , respectively. The drives and their associated computer-readable media provide nonvolatile storage of computer readable instructions, data structures, program modules and other data for the personal computer  100 .  
         [0029]    Although the exemplary environment described herein employs a hard disk, a removable magnetic disk  190  and a removable optical disk  192 , it should be appreciated by those skilled in the art that other types of computer readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs), and the like, may also be used in the exemplary operating environment. It is anticipated that a hand-held device implementing this invention would typically have only one mass-storage peripheral, either a micro hard disk or else flash memory or equivalent.  
         [0030]    A number of program modules may be stored on the hard disk, magnetic disk  190 , optical disk  192 , ROM  140  or RAM  150 , including an operating system  195 , one or more application programs  196 , other program modules  197 , and program data  198 . A user may enter commands and information into the personal computer  100  through input devices such as a keyboard  101  and pointing device  102 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit  110  through a serial port interface  106  that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port or a universal serial bus (USB). A monitor  107  or other type of display device is also connected to the system bus  130  via an interface, such as a video adapter  108 . In addition to the monitor, personal computers typically include other peripheral output devices (not shown), such as speakers and printers. Preferably, any implementation of the present invention is designed to be operable in a least case scenario only by touch, and does not always require the use of a keyboard or mouse.  
         [0031]    The personal computer  100  may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer  109 . The remote computer  109  may be another personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the personal computer  100 , although only a memory storage device  111  has been illustrated in FIG. 1. The logical connections depicted in FIG. 1 include a local area network (LAN)  112  and a wide area network (WAN)  113 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet. It is anticipated that a hand-held device used to implement the present invention would typically use a wireless LAN interface based on an infra-red or radio frequency communication link.  
         [0032]    When used in a LAN networking environment, the personal computer  100  is connected to the local network  112  through a network interface or adapter  114 . When used in a WAN networking environment, the personal computer  100  typically includes a modem  115  or other means for establishing a communications over the wide area network  113 , such as the Internet. The modem  115 , which may be internal or external, is connected to the system bus  130  via the serial port interface  106 . In a networked environment, program modules depicted relative to the personal computer  100 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.  
         [0033]    [0033]FIG. 2 is a simplified schematic block diagram of various elements of a reading device in accordance with a preferred embodiment of the present invention. Resident within memory  120  are a look-up table  300 , an application program  196 A for reading e-books, one or more e-book files  205 , and one or more other application programs  196 B (optional). Memory  120  also includes, among other things, an operating system  195 . It will be readily apparent that the e-book file may also be resident within other memory devices of the computing system of FIG. 1 such as hard disk drive  170 , magnetic disk  190 , optical disk  192 , or remote computer  109 . Further, those skilled in the art will appreciate that the present invention may be incorporated in any number of system architectures other than that of FIG. 1. In the embodiment of FIG. 2, the application program  196 A for reading e-books runs on the operating system platform  195 , displays one or more e-books  205 , and uses table  300  to identify and invoke pre-defined system commands. Table  300  and the techniques for invoking system commands in accordance with the present invention are discussed herein.  
         [0034]    In accordance with a preferred embodiment of the present invention, a link within a mark-up language document invokes a system command to be performed. System commands are generally functions or operations that may be performed by an operating system or other applications related to the mark-up language document. As preferred, the link is accompanied by an instruction to invoke and an alias to identify a specific system command to be invoked. The alias is a reference code identifying a pre-defined system command. In this regard, the following link may be used:  
         [0035]    &lt;A HREF=X-MSR1INVOKE:−100&gt;Link Text Goes Here&lt;/a&gt; 
         [0036]    The instruction to invoke the system command is the term “X-MSR1INVOKE” and the alias is the term “−100” in the above link. Those skilled in the art will appreciate that any number of such instructions and aliases may be used and still be considered within the scope of the present invention. The alias refers to a pre-defined system command, which may be ascertained from a look-up table identifying the system commands for each alias. The table  300  of FIG. 3 is illustrative in this regard. In the embodiment illustrated in FIG. 3, table  300  provides a first column  310  of various aliases ranging from −100 to +100. A second column  320  identifies the pre-defined system commands corresponding to the alias. For example, the alias −99 identifies the system command for adjusting the contrast a specified amount. Aliases  98 - 100  remain undefined. The table  300  may be subsequently amended to add new system commands or to alter, disable, and/or remove existing commands.  
         [0037]    In addition to aliases having certain pre-defined system commands, certain aliases may also be reserved for future development, including for example, applets for third-party applications. These system commands may be performed, for example, by other application programs  196 B.  
         [0038]    Any number of system commands may be performed by the invoking function of the present invention including, but not limited to, system configuration commands, networked operations, commerce functions, and utilities commands. System configuration commands may include, for example, Brightness (+,−), Contrast (+,−), Page Color (range: 0 to 512), Rotate ( 90 , 180 , 270 ), Visual Guides (hide/show), All Annotations (hide/show), Bookmarks (hide/show), Highlights (hide/show), Notes (hide/show), Drawings (hide/show), and Riffle Increments (range). Networked operations may include, for example, Network Lookup (lookup a definition of a term in a networked reference source), and Network Search (lookup references to a term in a networked index). Commerce functions may include, for example, Initiate Transaction, Initiate File Upload, and Form Post (send information to a server). Utilities commands may include, for example, Load Value (entering a value into the system to be operated on by next X-MSR INVOKE command).  
         [0039]    Advantageously, the table  300  pre-defines the various system commands that may be automatically invoked when the user selects the corresponding link. Further, since only those system commands that are provided in table  300  may be invoked, undesirable or even harmful system commands are thereby precluded from be invoked. Even further, table  300  may be subsequently modified and such changes to the table  300  may be applied to all links referencing alias defined by the table  300 . For example, a system command to increase the font by one increment may be altered to increase the font by three increments. Accordingly, the link referencing the system command to adjust the font will then adjust the font by three increments rather than one.  
         [0040]    [0040]FIG. 4 illustrates an example of how the present invention may be implemented within a system for reading mark-up language documents. FIG. 4 depicts a screen of an application program  400  showing a page from an e-book. The page is essentially a listing of links  405 - 430  that allow the user to invoke various system commands. The user may click on one of the links  405 - 430  using a pointing device, such as a mouse  102 , thereby automatically executing the selected system command. In this example, links  405 - 430  have embedded −1 through 4, respectively, in the mark-up language document. The corresponding pre-defined system commands for these aliases are identified by table  300  of FIG. 3. For example, the “Use Large Fonts” link  430  has an alias of 4 and may be written in the mark-up language document as follows:  
         [0041]    &lt;A HREF=X-MSR1INVOKE: 4&gt;Use Large Fonts&lt;/a&gt; 
         [0042]    By selecting the “Use Large Fonts” link  430 , the system command for adjusting font size is automatically invoked and a large font format is thereby applied. The large font setting is preferably applied to all e-books viewed by the reading program  400  until the “Use Small Fonts” link  430  is selected. Alternatively, the system command may apply to only that particular e-book that is being viewed, such that default settings are applied when other e-books are viewed.  
         [0043]    Referring still to FIG. 4, after the system command has been invoked, link  430  is automatically renamed to “Use Small Fonts”. The system senses that some of the system commands are complements of each other and renames the text visible on the screen to reflect the changed settings. FIGS. 5 and 6 respectively illustrate the font size of a page of an e-book before and after the link  430  was selected.  
         [0044]    In an alternative embodiment, more than one function may be invoked by a link. For example, the following link may be used to invoke two system commands:  
         [0045]    &lt;A HREF=X-MSR1INVOKE:−100, −99&gt;Link Text Goes Here&lt;/a&gt; 
         [0046]    [0046]FIG. 7 is a flow chart depicting the process by which a system command may be invoked in accordance with a preferred embodiment of the present invention. Though the present invention covers any mark-up language document and a system that interacts with such mark-up language documents, the following example is presented in the specific application of a reading device. At step  705 , a reading program parses the mark-up language document to recognize the links that are present in the document. At step  710 , the program monitors whether the user has selected a link. Once the user selects a link, the program reads the link to determine the form of the link. One option is that the link may identify a standard protocol in which case the program follows operation in accordance with known techniques (step  725 ). For example, if the link refers to another mark-up language document, the software will navigate to and display that document. The other option is that the link indicates that a system resource is to be invoked, namely it recites the “X-MSR1INVOKE” protocol. At step  720 , the link is then checked to identify the alias for that link and table  300  is checked to identify the specific system command to be performed. At step  730 , the program performs the pre-defined system command. The system then returns to step  710  where it waits for the user to select another link.  
         [0047]    Advantageously, the present invention overcomes many of the limitation of the prior art. For example, the present invention provides a technique to invoke system commands automatically from within a mark-up language document. As another example, since only pre-defined system commands may be invoked as provided in look-up table  300 , undesirable or even harmful system commands are thereby precluded from being invoked. As yet another example, since the system commands are not embedded within the document itself, the size of the document is reduced. As even another example, table  300  may be subsequently modified to alter existing system commands and even to include additional system commands.  
         [0048]    It will be apparent to those skilled in the art that application of the present invention need not merely be utilized in conjunction with a reading device. The present invention may be implemented within any computing environment and may be used with any application using mark-up language documents including, for example and without limitation, a web browser or a word processor.  
         [0049]    In the foregoing specification, the present invention has been described with reference to specific exemplary embodiments thereof. Although the invention has been described in terms of a preferred embodiment, those skilled in the art will recognize that various modifications, embodiments or variations of the invention can be practiced within the spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, therefore, to be regarded in an illustrated rather than restrictive sense. Accordingly, it is not intended that the invention be limited except as may be necessary in view of the appended claims.  
         [0050]    The present invention has been described in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.